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• How to Write an Abstract | Steps & Examples

How to Write an Abstract | Steps & Examples

Published on 1 March 2019 by Shona McCombes . Revised on 10 October 2022 by Eoghan Ryan.

An abstract is a short summary of a longer work (such as a dissertation or research paper ). The abstract concisely reports the aims and outcomes of your research, so that readers know exactly what your paper is about.

Although the structure may vary slightly depending on your discipline, your abstract should describe the purpose of your work, the methods you’ve used, and the conclusions you’ve drawn.

One common way to structure your abstract is to use the IMRaD structure. This stands for:

• Introduction

Abstracts are usually around 100–300 words, but there’s often a strict word limit, so make sure to check the relevant requirements.

In a dissertation or thesis , include the abstract on a separate page, after the title page and acknowledgements but before the table of contents .

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Table of contents

Abstract example, when to write an abstract, step 1: introduction, step 2: methods, step 3: results, step 4: discussion, tips for writing an abstract, frequently asked questions about abstracts.

Hover over the different parts of the abstract to see how it is constructed.

This paper examines the role of silent movies as a mode of shared experience in the UK during the early twentieth century. At this time, high immigration rates resulted in a significant percentage of non-English-speaking citizens. These immigrants faced numerous economic and social obstacles, including exclusion from public entertainment and modes of discourse (newspapers, theater, radio).

Incorporating evidence from reviews, personal correspondence, and diaries, this study demonstrates that silent films were an affordable and inclusive source of entertainment. It argues for the accessible economic and representational nature of early cinema. These concerns are particularly evident in the low price of admission and in the democratic nature of the actors’ exaggerated gestures, which allowed the plots and action to be easily grasped by a diverse audience despite language barriers.

Keywords: silent movies, immigration, public discourse, entertainment, early cinema, language barriers.

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You will almost always have to include an abstract when:

• Completing a thesis or dissertation
• Submitting a research paper to an academic journal
• Writing a book proposal
• Applying for research grants

It’s easiest to write your abstract last, because it’s a summary of the work you’ve already done. Your abstract should:

• Be a self-contained text, not an excerpt from your paper
• Be fully understandable on its own
• Reflect the structure of your larger work

Start by clearly defining the purpose of your research. What practical or theoretical problem does the research respond to, or what research question did you aim to answer?

You can include some brief context on the social or academic relevance of your topic, but don’t go into detailed background information. If your abstract uses specialised terms that would be unfamiliar to the average academic reader or that have various different meanings, give a concise definition.

After identifying the problem, state the objective of your research. Use verbs like “investigate,” “test,” “analyse,” or “evaluate” to describe exactly what you set out to do.

This part of the abstract can be written in the present or past simple tense  but should never refer to the future, as the research is already complete.

• This study will investigate the relationship between coffee consumption and productivity.
• This study investigates the relationship between coffee consumption and productivity.

Next, indicate the research methods that you used to answer your question. This part should be a straightforward description of what you did in one or two sentences. It is usually written in the past simple tense, as it refers to completed actions.

• Structured interviews will be conducted with 25 participants.
• Structured interviews were conducted with 25 participants.

Don’t evaluate validity or obstacles here — the goal is not to give an account of the methodology’s strengths and weaknesses, but to give the reader a quick insight into the overall approach and procedures you used.

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Next, summarise the main research results . This part of the abstract can be in the present or past simple tense.

• Our analysis has shown a strong correlation between coffee consumption and productivity.
• Our analysis shows a strong correlation between coffee consumption and productivity.
• Our analysis showed a strong correlation between coffee consumption and productivity.

Depending on how long and complex your research is, you may not be able to include all results here. Try to highlight only the most important findings that will allow the reader to understand your conclusions.

Finally, you should discuss the main conclusions of your research : what is your answer to the problem or question? The reader should finish with a clear understanding of the central point that your research has proved or argued. Conclusions are usually written in the present simple tense.

• We concluded that coffee consumption increases productivity.
• We conclude that coffee consumption increases productivity.

If there are important limitations to your research (for example, related to your sample size or methods), you should mention them briefly in the abstract. This allows the reader to accurately assess the credibility and generalisability of your research.

If your aim was to solve a practical problem, your discussion might include recommendations for implementation. If relevant, you can briefly make suggestions for further research.

If your paper will be published, you might have to add a list of keywords at the end of the abstract. These keywords should reference the most important elements of the research to help potential readers find your paper during their own literature searches.

Be aware that some publication manuals, such as APA Style , have specific formatting requirements for these keywords.

It can be a real challenge to condense your whole work into just a couple of hundred words, but the abstract will be the first (and sometimes only) part that people read, so it’s important to get it right. These strategies can help you get started.

Read other abstracts

The best way to learn the conventions of writing an abstract in your discipline is to read other people’s. You probably already read lots of journal article abstracts while conducting your literature review —try using them as a framework for structure and style.

You can also find lots of dissertation abstract examples in thesis and dissertation databases .

Reverse outline

Not all abstracts will contain precisely the same elements. For longer works, you can write your abstract through a process of reverse outlining.

For each chapter or section, list keywords and draft one to two sentences that summarise the central point or argument. This will give you a framework of your abstract’s structure. Next, revise the sentences to make connections and show how the argument develops.

Write clearly and concisely

A good abstract is short but impactful, so make sure every word counts. Each sentence should clearly communicate one main point.

To keep your abstract or summary short and clear:

• Avoid passive sentences: Passive constructions are often unnecessarily long. You can easily make them shorter and clearer by using the active voice.
• Avoid long sentences: Substitute longer expressions for concise expressions or single words (e.g., “In order to” for “To”).
• Avoid obscure jargon: The abstract should be understandable to readers who are not familiar with your topic.
• Avoid repetition and filler words: Replace nouns with pronouns when possible and eliminate unnecessary words.
• Avoid detailed descriptions: An abstract is not expected to provide detailed definitions, background information, or discussions of other scholars’ work. Instead, include this information in the body of your thesis or paper.

If you’re struggling to edit down to the required length, you can get help from expert editors with Scribbr’s professional proofreading services .

Check your formatting

If you are writing a thesis or dissertation or submitting to a journal, there are often specific formatting requirements for the abstract—make sure to check the guidelines and format your work correctly. For APA research papers you can follow the APA abstract format .

Checklist: Abstract

The word count is within the required length, or a maximum of one page.

The abstract appears after the title page and acknowledgements and before the table of contents .

I have clearly stated my research problem and objectives.

I have briefly described my methodology .

I have summarized the most important results .

I have stated my main conclusions .

I have mentioned any important limitations and recommendations.

The abstract can be understood by someone without prior knowledge of the topic.

You've written a great abstract! Use the other checklists to continue improving your thesis or dissertation.

An abstract is a concise summary of an academic text (such as a journal article or dissertation ). It serves two main purposes:

• To help potential readers determine the relevance of your paper for their own research.
• To communicate your key findings to those who don’t have time to read the whole paper.

Abstracts are often indexed along with keywords on academic databases, so they make your work more easily findable. Since the abstract is the first thing any reader sees, it’s important that it clearly and accurately summarises the contents of your paper.

An abstract for a thesis or dissertation is usually around 150–300 words. There’s often a strict word limit, so make sure to check your university’s requirements.

The abstract is the very last thing you write. You should only write it after your research is complete, so that you can accurately summarize the entirety of your thesis or paper.

Avoid citing sources in your abstract . There are two reasons for this:

• The abstract should focus on your original research, not on the work of others.
• The abstract should be self-contained and fully understandable without reference to other sources.

There are some circumstances where you might need to mention other sources in an abstract: for example, if your research responds directly to another study or focuses on the work of a single theorist. In general, though, don’t include citations unless absolutely necessary.

The abstract appears on its own page, after the title page and acknowledgements but before the table of contents .

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• How to Write an Abstract for a Dissertation or Thesis
• Doing a PhD

What is a Thesis or Dissertation Abstract?

The Cambridge English Dictionary defines an abstract in academic writing as being “ a few sentences that give the main ideas in an article or a scientific paper ” and the Collins English Dictionary says “ an abstract of an article, document, or speech is a short piece of writing that gives the main points of it ”.

Whether you’re writing up your Master’s dissertation or PhD thesis, the abstract will be a key element of this document that you’ll want to make sure you give proper attention to.

What is the Purpose of an Abstract?

The aim of a thesis abstract is to give the reader a broad overview of what your research project was about and what you found that was novel, before he or she decides to read the entire thesis. The reality here though is that very few people will read the entire thesis, and not because they’re necessarily disinterested but because practically it’s too large a document for most people to have the time to read. The exception to this is your PhD examiner, however know that even they may not read the entire length of the document.

Some people may still skip to and read specific sections throughout your thesis such as the methodology, but the fact is that the abstract will be all that most read and will therefore be the section they base their opinions about your research on. In short, make sure you write a good, well-structured abstract.

How Long Should an Abstract Be?

If you’re a PhD student, having written your 100,000-word thesis, the abstract will be the 300 word summary included at the start of the thesis that succinctly explains the motivation for your study (i.e. why this research was needed), the main work you did (i.e. the focus of each chapter), what you found (the results) and concluding with how your research study contributed to new knowledge within your field.

Woodrow Wilson, the 28th President of the United States of America, once famously said:

The point here is that it’s easier to talk open-endedly about a subject that you know a lot about than it is to condense the key points into a 10-minute speech; the same applies for an abstract. Three hundred words is not a lot of words which makes it even more difficult to condense three (or more) years of research into a coherent, interesting story.

What Makes a Good PhD Thesis Abstract?

Whilst the abstract is one of the first sections in your PhD thesis, practically it’s probably the last aspect that you’ll ending up writing before sending the document to print. The reason being that you can’t write a summary about what you did, what you found and what it means until you’ve done the work.

A good abstract is one that can clearly explain to the reader in 300 words:

• What your research field actually is,
• What the gap in knowledge was in your field,
• The overarching aim and objectives of your PhD in response to these gaps,
• What methods you employed to achieve these,
• You key results and findings,
• How your work has added to further knowledge in your field of study.

Another way to think of this structure is:

• Introduction,
• Aims and objectives,
• Discussion,
• Conclusion.

Following this ‘formulaic’ approach to writing the abstract should hopefully make it a little easier to write but you can already see here that there’s a lot of information to convey in a very limited number of words.

How Do You Write a Good PhD Thesis Abstract?

The biggest challenge you’ll have is getting all the 6 points mentioned above across in your abstract within the limit of 300 words . Your particular university may give some leeway in going a few words over this but it’s good practice to keep within this; the art of succinctly getting your information across is an important skill for a researcher to have and one that you’ll be called on to use regularly as you write papers for peer review.

Keep It Concise

Every word in the abstract is important so make sure you focus on only the key elements of your research and the main outcomes and significance of your project that you want the reader to know about. You may have come across incidental findings during your research which could be interesting to discuss but this should not happen in the abstract as you simply don’t have enough words. Furthermore, make sure everything you talk about in your thesis is actually described in the main thesis.

Make a Unique Point Each Sentence

Keep the sentences short and to the point. Each sentence should give the reader new, useful information about your research so there’s no need to write out your project title again. Give yourself one or two sentences to introduce your subject area and set the context for your project. Then another sentence or two to explain the gap in the knowledge; there’s no need or expectation for you to include references in the abstract.

Explain Your Research

Some people prefer to write their overarching aim whilst others set out their research questions as they correspond to the structure of their thesis chapters; the approach you use is up to you, as long as the reader can understand what your dissertation or thesis had set out to achieve. Knowing this will help the reader better understand if your results help to answer the research questions or if further work is needed.

Keep It Factual

Keep the content of the abstract factual; that is to say that you should avoid bringing too much or any opinion into it, which inevitably can make the writing seem vague in the points you’re trying to get across and even lacking in structure.

Write, Edit and Then Rewrite

Spend suitable time editing your text, and if necessary, completely re-writing it. Show the abstract to others and ask them to explain what they understand about your research – are they able to explain back to you each of the 6 structure points, including why your project was needed, the research questions and results, and the impact it had on your research field? It’s important that you’re able to convey what new knowledge you contributed to your field but be mindful when writing your abstract that you don’t inadvertently overstate the conclusions, impact and significance of your work.

Thesis and Dissertation Abstract Examples

Perhaps the best way to understand how to write a thesis abstract is to look at examples of what makes a good and bad abstract.

Example of A Bad Abstract

Let’s start with an example of a bad thesis abstract:

In this project on “The Analysis of the Structural Integrity of 3D Printed Polymers for use in Aircraft”, my research looked at how 3D printing of materials can help the aviation industry in the manufacture of planes. Plane parts can be made at a lower cost using 3D printing and made lighter than traditional components. This project investigated the structural integrity of EBM manufactured components, which could revolutionise the aviation industry.

What Makes This a Bad Abstract

Hopefully you’ll have spotted some of the reasons this would be considered a poor abstract, not least because the author used up valuable words by repeating the lengthy title of the project in the abstract.

Working through our checklist of the 6 key points you want to convey to the reader:

• There has been an attempt to introduce the research area , albeit half-way through the abstract but it’s not clear if this is a materials science project about 3D printing or is it about aircraft design.
• There’s no explanation about where the gap in the knowledge is that this project attempted to address.
• We can see that this project was focussed on the topic of structural integrity of materials in aircraft but the actual research aims or objectives haven’t been defined.
• There’s no mention at all of what the author actually did to investigate structural integrity. For example was this an experimental study involving real aircraft, or something in the lab, computer simulations etc.
• The author also doesn’t tell us a single result of his research, let alone the key findings !
• There’s a bold claim in the last sentence of the abstract that this project could revolutionise the aviation industry, and this may well be the case, but based on the abstract alone there is no evidence to support this as it’s not even clear what the author did .

This is an extreme example but is a good way to illustrate just how unhelpful a poorly written abstract can be. At only 71 words long, it definitely hasn’t maximised the amount of information that could be presented and the what they have presented has lacked clarity and structure.

A final point to note is the use of the EBM acronym, which stands for Electron Beam Melting in the context of 3D printing; this is a niche acronym for the author to assume that the reader would know the meaning of. It’s best to avoid acronyms in your abstract all together even if it’s something that you might expect most people to know about, unless you specifically define the meaning first.

Example of A Good Abstract

Having seen an example of a bad thesis abstract, now lets look at an example of a good PhD thesis abstract written about the same (fictional) project:

Additive manufacturing (AM) of titanium alloys has the potential to enable cheaper and lighter components to be produced with customised designs for use in aircraft engines. Whilst the proof-of-concept of these have been promising, the structural integrity of AM engine parts in response to full thrust and temperature variations is not clear.

The primary aim of this project was to determine the fracture modes and mechanisms of AM components designed for use in Boeing 747 engines. To achieve this an explicit finite element (FE) model was developed to simulate the environment and parameters that the engine is exposed to during flight. The FE model was validated using experimental data replicating the environmental parameters in a laboratory setting using ten AM engine components provided by the industry sponsor. The validated FE model was then used to investigate the extent of crack initiation and propagation as the environment parameters were adjusted.

This project was the first to investigate fracture patterns in AM titanium components used in aircraft engines; the key finding was that the presence of cavities within the structures due to errors in the printing process, significantly increased the risk of fracture. Secondly, the simulations showed that cracks formed within AM parts were more likely to worsen and lead to component failure at subzero temperatures when compared to conventionally manufactured parts. This has demonstrated an important safety concern which needs to be addressed before AM parts can be used in commercial aircraft.

What Makes This a Good Abstract

Having read this ‘good abstract’ you should have a much better understand about what the subject area is about, where the gap in the knowledge was, the aim of the project, the methods that were used, key results and finally the significance of these results. To break these points down further, from this good abstract we now know that:

• The research area is around additive manufacturing (i.e. 3D printing) of materials for use in aircraft.
• The gap in knowledge was how these materials will behave structural when used in aircraft engines.
• The aim was specifically to investigate how the components can fracture.
• The methods used to investigate this were a combination of computational and lab based experimental modelling.
• The key findings were the increased risk of fracture of these components due to the way they are manufactured.
• The significance of these findings were that it showed a potential risk of component failure that could comprise the safety of passengers and crew on the aircraft.

The abstract text has a much clearer flow through these different points in how it’s written and has made much better use of the available word count. Acronyms have even been used twice in this good abstract but they were clearly defined the first time they were introduced in the text so that there was no confusion about their meaning.

The abstract you write for your dissertation or thesis should succinctly explain to the reader why the work of your research was needed, what you did, what you found and what it means. Most people that come across your thesis, including any future employers, are likely to read only your abstract. Even just for this reason alone, it’s so important that you write the best abstract you can; this will not only convey your research effectively but also put you in the best light possible as a researcher.

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How to structure your dissertation abstract

Abstracts written for undergraduate and master's level dissertations have a number of structural components [ NOTE ]. Even though every dissertation is different, these structural components are likely to be relevant for most dissertations. When writing the dissertation abstract, the most important thing to remember is why your research was significant. This should have been clearly explained in the introductory chapter of your dissertation ( Chapter One: Introduction ). Understanding the significance of your research is important because how much you write for each component of the abstract (in terms of word count or number of sentences) will depend on the relative importance of each of these components to your research.

There are four major structural components, which aim to let the reader know about the background to and significance of your study, the research strategy being followed, the findings of the research, and the conclusions that were made. You should write one or a number of sentences for each of these components, with each making up a part of the 150 to 350 words that are typically written in dissertation abstracts. This section sets out and explains these structural components. These four major components are:

• COMPONENT #1: Study background and significance
• COMPONENT #2: Components of your research strategy
• COMPONENT #3: Findings
• COMPONENT #4: Conclusions

COMPONENT #1 Study background and significance

The first few sentences of the dissertation abstract highlight the background to your research, as well as the significance of the study. Hopefully, by the time you come to write the abstract, you will already know why your study is significant.

In explaining the significance of your study, you will also need to provide some context for your research. This includes the problem that you are addressing and your motivation for conducting the study. In building the background to the study, this part of the abstract should address questions such as:

What is the purpose of the research?

Why did you carry out the research?

How is the study significant? Why should anyone care or why do they care (is the study interesting)?

Remember, all of this needs to be encompassed within just a few sentences. Therefore, only outline those aspects of your study that you feel are the most important; those aspects that you think will catch the reader's attention.

COMPONENT #2 Components of your research strategy

The relative importance of the methodological components discussed in the dissertation abstract will depend on whether any of these components made the study significant in some way. Ask yourself the question: Did any of the following components of research strategy help make my study significant?

The broad research design (e.g., qualitative, quantitative, mixed, etc.)

The type of research design (e.g., experimental research, case study approach, grounded theory, ethnography, etc.)

The research methods (e.g., survey, interviews, focus groups, observation, etc.)

The analytical techniques used (e.g., content analysis, statistical analyses, etc.)

If the answer is YES , greater focus (and word count) should probably be dedicated to explaining these components of research strategy in the dissertation abstract. If not, try and summarise the components used more succinctly (i.e., in fewer words). Since the way that you would write the research strategy part of your dissertation abstract will vary depending on the relative significance of these components to your study, we have produced examples to help.

In explaining the approach to research strategy that you adopted in this part of your dissertation abstract, addressing some of the following questions may help:

What research design guided your study?

What was the scope of your study?

What research methods did you use?

What were the main ideas, constructs and/or variables that you examined, measured, controlled and/or ignored?

What was your unit of analysis?

What was your sample (and population)?

What analysis techniques did you use to arrive at your findings?

Often, you will be able to combine the answer to a number of these questions in a single sentence, which will help make the abstract more concise and succinct.

COMPONENT #3 Major findings

Following a discussion of the components of your research strategy, the dissertation abstract should move on to present the main findings from your research. We use the word findings and not results to emphasise the fact that the abstract is not the section where you should include lots of data; and it should definitely not include any analysis. Leave this to the Results/Findings chapter of your dissertation (often Chapter Four: Results/Findings ). Remember that the findings part of the dissertation abstract should focus on answering your research questions and/or hypotheses.

It may help to answer some of the following questions in order to write this part of the dissertation abstract:

Did the findings answer your research questions and/or hypotheses?

What did the findings show in terms of these research questions and/or hypotheses?

What are the most important findings?

What is the significance of your findings?

To what extent are your findings trustworthy (i.e., reliable, generalisable, consistent, dependable, etc.)?

You should avoid making comments that are vague or over-exaggerate your findings. You should also ensure that you explain the findings in a way that non-experts could understand without having to read additional parts of your dissertation.

COMPONENT #4 Conclusions

The final part of your dissertation abstract should focus on the conclusions from your research and the resultant implications. Bearing in mind the findings that have just been discussed, you need to address questions such as:

What has been learned?

What are the implications of the findings?

Is there potential for generalisation of your findings?

What are the limitations of your research?

When writing the conclusion part of your abstract, remember that these conclusions should be precise and concise. There is no need to re-summarise what you have already discussed or the contents of your dissertation. This is an informative abstract, not a descriptive one. If you are unsure of the difference, you may find the section, Choosing between dissertation abstract styles: Descriptive and informative , helpful. Furthermore, be careful not to make claims that cannot be supported by your findings. There is always a danger to over-exaggerate and/or over-generalise in this part of the abstract, which should be avoided. It is unlikely that you will have changed the world through your study, but you may still have added something significant to the literature, so try and strike the right balance.

NOTE: This article is based on the use of the informative abstract style, not the descriptive style; the former being the typical style adopted in undergraduate and master's dissertations and theses. For a comparison of the two styles - descriptive and informative - see the article, Choosing between dissertation abstract styles: Descriptive or informative .

In the next section, Useful phrases when writing a dissertation abstract , we set out some phrases that you may find useful when writing up your dissertation abstract.

Writing an Abstract for Your Research Paper

Definition and Purpose of Abstracts

An abstract is a short summary of your (published or unpublished) research paper, usually about a paragraph (c. 6-7 sentences, 150-250 words) long. A well-written abstract serves multiple purposes:

• an abstract lets readers get the gist or essence of your paper or article quickly, in order to decide whether to read the full paper;
• an abstract prepares readers to follow the detailed information, analyses, and arguments in your full paper;
• and, later, an abstract helps readers remember key points from your paper.

It’s also worth remembering that search engines and bibliographic databases use abstracts, as well as the title, to identify key terms for indexing your published paper. So what you include in your abstract and in your title are crucial for helping other researchers find your paper or article.

If you are writing an abstract for a course paper, your professor may give you specific guidelines for what to include and how to organize your abstract. Similarly, academic journals often have specific requirements for abstracts. So in addition to following the advice on this page, you should be sure to look for and follow any guidelines from the course or journal you’re writing for.

The Contents of an Abstract

Abstracts contain most of the following kinds of information in brief form. The body of your paper will, of course, develop and explain these ideas much more fully. As you will see in the samples below, the proportion of your abstract that you devote to each kind of information—and the sequence of that information—will vary, depending on the nature and genre of the paper that you are summarizing in your abstract. And in some cases, some of this information is implied, rather than stated explicitly. The Publication Manual of the American Psychological Association , which is widely used in the social sciences, gives specific guidelines for what to include in the abstract for different kinds of papers—for empirical studies, literature reviews or meta-analyses, theoretical papers, methodological papers, and case studies.

Here are the typical kinds of information found in most abstracts:

• the context or background information for your research; the general topic under study; the specific topic of your research
• the central questions or statement of the problem your research addresses
• what’s already known about this question, what previous research has done or shown
• the main reason(s) , the exigency, the rationale , the goals for your research—Why is it important to address these questions? Are you, for example, examining a new topic? Why is that topic worth examining? Are you filling a gap in previous research? Applying new methods to take a fresh look at existing ideas or data? Resolving a dispute within the literature in your field? . . .
• your research and/or analytical methods
• your main findings , results , or arguments
• the significance or implications of your findings or arguments.

Your abstract should be intelligible on its own, without a reader’s having to read your entire paper. And in an abstract, you usually do not cite references—most of your abstract will describe what you have studied in your research and what you have found and what you argue in your paper. In the body of your paper, you will cite the specific literature that informs your research.

When to Write Your Abstract

Although you might be tempted to write your abstract first because it will appear as the very first part of your paper, it’s a good idea to wait to write your abstract until after you’ve drafted your full paper, so that you know what you’re summarizing.

What follows are some sample abstracts in published papers or articles, all written by faculty at UW-Madison who come from a variety of disciplines. We have annotated these samples to help you see the work that these authors are doing within their abstracts.

Choosing Verb Tenses within Your Abstract

The social science sample (Sample 1) below uses the present tense to describe general facts and interpretations that have been and are currently true, including the prevailing explanation for the social phenomenon under study. That abstract also uses the present tense to describe the methods, the findings, the arguments, and the implications of the findings from their new research study. The authors use the past tense to describe previous research.

The humanities sample (Sample 2) below uses the past tense to describe completed events in the past (the texts created in the pulp fiction industry in the 1970s and 80s) and uses the present tense to describe what is happening in those texts, to explain the significance or meaning of those texts, and to describe the arguments presented in the article.

The science samples (Samples 3 and 4) below use the past tense to describe what previous research studies have done and the research the authors have conducted, the methods they have followed, and what they have found. In their rationale or justification for their research (what remains to be done), they use the present tense. They also use the present tense to introduce their study (in Sample 3, “Here we report . . .”) and to explain the significance of their study (In Sample 3, This reprogramming . . . “provides a scalable cell source for. . .”).

Sample Abstract 1

From the social sciences.

Reporting new findings about the reasons for increasing economic homogamy among spouses

Gonalons-Pons, Pilar, and Christine R. Schwartz. “Trends in Economic Homogamy: Changes in Assortative Mating or the Division of Labor in Marriage?” Demography , vol. 54, no. 3, 2017, pp. 985-1005.

Sample Abstract 2

From the humanities.

Analyzing underground pulp fiction publications in Tanzania, this article makes an argument about the cultural significance of those publications

Emily Callaci. “Street Textuality: Socialism, Masculinity, and Urban Belonging in Tanzania’s Pulp Fiction Publishing Industry, 1975-1985.” Comparative Studies in Society and History , vol. 59, no. 1, 2017, pp. 183-210.

Sample Abstract/Summary 3

From the sciences.

Reporting a new method for reprogramming adult mouse fibroblasts into induced cardiac progenitor cells

Lalit, Pratik A., Max R. Salick, Daryl O. Nelson, Jayne M. Squirrell, Christina M. Shafer, Neel G. Patel, Imaan Saeed, Eric G. Schmuck, Yogananda S. Markandeya, Rachel Wong, Martin R. Lea, Kevin W. Eliceiri, Timothy A. Hacker, Wendy C. Crone, Michael Kyba, Daniel J. Garry, Ron Stewart, James A. Thomson, Karen M. Downs, Gary E. Lyons, and Timothy J. Kamp. “Lineage Reprogramming of Fibroblasts into Proliferative Induced Cardiac Progenitor Cells by Defined Factors.” Cell Stem Cell , vol. 18, 2016, pp. 354-367.

Sample Abstract 4, a Structured Abstract

Reporting results about the effectiveness of antibiotic therapy in managing acute bacterial sinusitis, from a rigorously controlled study

Note: This journal requires authors to organize their abstract into four specific sections, with strict word limits. Because the headings for this structured abstract are self-explanatory, we have chosen not to add annotations to this sample abstract.

Wald, Ellen R., David Nash, and Jens Eickhoff. “Effectiveness of Amoxicillin/Clavulanate Potassium in the Treatment of Acute Bacterial Sinusitis in Children.” Pediatrics , vol. 124, no. 1, 2009, pp. 9-15.

“OBJECTIVE: The role of antibiotic therapy in managing acute bacterial sinusitis (ABS) in children is controversial. The purpose of this study was to determine the effectiveness of high-dose amoxicillin/potassium clavulanate in the treatment of children diagnosed with ABS.

METHODS : This was a randomized, double-blind, placebo-controlled study. Children 1 to 10 years of age with a clinical presentation compatible with ABS were eligible for participation. Patients were stratified according to age (<6 or ≥6 years) and clinical severity and randomly assigned to receive either amoxicillin (90 mg/kg) with potassium clavulanate (6.4 mg/kg) or placebo. A symptom survey was performed on days 0, 1, 2, 3, 5, 7, 10, 20, and 30. Patients were examined on day 14. Children’s conditions were rated as cured, improved, or failed according to scoring rules.

RESULTS: Two thousand one hundred thirty-five children with respiratory complaints were screened for enrollment; 139 (6.5%) had ABS. Fifty-eight patients were enrolled, and 56 were randomly assigned. The mean age was 6630 months. Fifty (89%) patients presented with persistent symptoms, and 6 (11%) presented with nonpersistent symptoms. In 24 (43%) children, the illness was classified as mild, whereas in the remaining 32 (57%) children it was severe. Of the 28 children who received the antibiotic, 14 (50%) were cured, 4 (14%) were improved, 4(14%) experienced treatment failure, and 6 (21%) withdrew. Of the 28children who received placebo, 4 (14%) were cured, 5 (18%) improved, and 19 (68%) experienced treatment failure. Children receiving the antibiotic were more likely to be cured (50% vs 14%) and less likely to have treatment failure (14% vs 68%) than children receiving the placebo.

CONCLUSIONS : ABS is a common complication of viral upper respiratory infections. Amoxicillin/potassium clavulanate results in significantly more cures and fewer failures than placebo, according to parental report of time to resolution.” (9)

Some Excellent Advice about Writing Abstracts for Basic Science Research Papers, by Professor Adriano Aguzzi from the Institute of Neuropathology at the University of Zurich:

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How to Write an Abstract (With Examples)

Sarah Oakley

Table of Contents

What is an abstract in a paper, how long should an abstract be, 5 steps for writing an abstract, examples of an abstract, how prowritingaid can help you write an abstract.

If you are writing a scientific research paper or a book proposal, you need to know how to write an abstract, which summarizes the contents of the paper or book.

When researchers are looking for peer-reviewed papers to use in their studies, the first place they will check is the abstract to see if it applies to their work. Therefore, your abstract is one of the most important parts of your entire paper.

In this article, we’ll explain what an abstract is, what it should include, and how to write one.

An abstract is a concise summary of the details within a report. Some abstracts give more details than others, but the main things you’ll be talking about are why you conducted the research, what you did, and what the results show.

When a reader is deciding whether to read your paper completely, they will first look at the abstract. You need to be concise in your abstract and give the reader the most important information so they can determine if they want to read the whole paper.

Remember that an abstract is the last thing you’ll want to write for the research paper because it directly references parts of the report. If you haven’t written the report, you won’t know what to include in your abstract.

If you are writing a paper for a journal or an assignment, the publication or academic institution might have specific formatting rules for how long your abstract should be. However, if they don’t, most abstracts are between 150 and 300 words long.

A short word count means your writing has to be precise and without filler words or phrases. Once you’ve written a first draft, you can always use an editing tool, such as ProWritingAid, to identify areas where you can reduce words and increase readability.

If your abstract is over the word limit, and you’ve edited it but still can’t figure out how to reduce it further, your abstract might include some things that aren’t needed. Here’s a list of three elements you can remove from your abstract:

Discussion : You don’t need to go into detail about the findings of your research because your reader will find your discussion within the paper.

Definition of terms : Your readers are interested the field you are writing about, so they are likely to understand the terms you are using. If not, they can always look them up. Your readers do not expect you to give a definition of terms in your abstract.

References and citations : You can mention there have been studies that support or have inspired your research, but you do not need to give details as the reader will find them in your bibliography.

Good writing = better grades

ProWritingAid will help you improve the style, strength, and clarity of all your assignments.

If you’ve never written an abstract before, and you’re wondering how to write an abstract, we’ve got some steps for you to follow. It’s best to start with planning your abstract, so we’ve outlined the details you need to include in your plan before you write.

Remember to consider your audience when you’re planning and writing your abstract. They are likely to skim read your abstract, so you want to be sure your abstract delivers all the information they’re expecting to see at key points.

1. What Should an Abstract Include?

Abstracts have a lot of information to cover in a short number of words, so it’s important to know what to include. There are three elements that need to be present in your abstract:

Your context is the background for where your research sits within your field of study. You should briefly mention any previous scientific papers or experiments that have led to your hypothesis and how research develops in those studies.

Your hypothesis is your prediction of what your study will show. As you are writing your abstract after you have conducted your research, you should still include your hypothesis in your abstract because it shows the motivation for your paper.

Throughout your abstract, you also need to include keywords and phrases that will help researchers to find your article in the databases they’re searching. Make sure the keywords are specific to your field of study and the subject you’re reporting on, otherwise your article might not reach the relevant audience.

2. Can You Use First Person in an Abstract?

You might think that first person is too informal for a research paper, but it’s not. Historically, writers of academic reports avoided writing in first person to uphold the formality standards of the time. However, first person is more accepted in research papers in modern times.

If you’re still unsure whether to write in first person for your abstract, refer to any style guide rules imposed by the journal you’re writing for or your teachers if you are writing an assignment.

3. Abstract Structure

Some scientific journals have strict rules on how to structure an abstract, so it’s best to check those first. If you don’t have any style rules to follow, try using the IMRaD structure, which stands for Introduction, Methodology, Results, and Discussion.

Following the IMRaD structure, start with an introduction. The amount of background information you should include depends on your specific research area. Adding a broad overview gives you less room to include other details. Remember to include your hypothesis in this section.

The next part of your abstract should cover your methodology. Try to include the following details if they apply to your study:

What type of research was conducted?

How were the test subjects sampled?

What were the sample sizes?

What was done to each group?

How long was the experiment?

How was data recorded and interpreted?

Following the methodology, include a sentence or two about the results, which is where your reader will determine if your research supports or contradicts their own investigations.

The results are also where most people will want to find out what your outcomes were, even if they are just mildly interested in your research area. You should be specific about all the details but as concise as possible.

The last few sentences are your conclusion. It needs to explain how your findings affect the context and whether your hypothesis was correct. Include the primary take-home message, additional findings of importance, and perspective. Also explain whether there is scope for further research into the subject of your report.

Your conclusion should be honest and give the reader the ultimate message that your research shows. Readers trust the conclusion, so make sure you’re not fabricating the results of your research. Some readers won’t read your entire paper, but this section will tell them if it’s worth them referencing it in their own study.

4. How to Start an Abstract

The first line of your abstract should give your reader the context of your report by providing background information. You can use this sentence to imply the motivation for your research.

You don’t need to use a hook phrase or device in your first sentence to grab the reader’s attention. Your reader will look to establish relevance quickly, so readability and clarity are more important than trying to persuade the reader to read on.

5. How to Format an Abstract

Most abstracts use the same formatting rules, which help the reader identify the abstract so they know where to look for it.

Here’s a list of formatting guidelines for writing an abstract:

Stick to one paragraph

Use block formatting with no indentation at the beginning

Put your abstract straight after the title and acknowledgements pages

Use present or past tense, not future tense

There are two primary types of abstract you could write for your paper—descriptive and informative.

An informative abstract is the most common, and they follow the structure mentioned previously. They are longer than descriptive abstracts because they cover more details.

Descriptive abstracts differ from informative abstracts, as they don’t include as much discussion or detail. The word count for a descriptive abstract is between 50 and 150 words.

Here is an example of an informative abstract:

A growing trend exists for authors to employ a more informal writing style that uses “we” in academic writing to acknowledge one’s stance and engagement. However, few studies have compared the ways in which the first-person pronoun “we” is used in the abstracts and conclusions of empirical papers. To address this lacuna in the literature, this study conducted a systematic corpus analysis of the use of “we” in the abstracts and conclusions of 400 articles collected from eight leading electrical and electronic (EE) engineering journals. The abstracts and conclusions were extracted to form two subcorpora, and an integrated framework was applied to analyze and seek to explain how we-clusters and we-collocations were employed. Results revealed whether authors’ use of first-person pronouns partially depends on a journal policy. The trend of using “we” showed that a yearly increase occurred in the frequency of “we” in EE journal papers, as well as the existence of three “we-use” types in the article conclusions and abstracts: exclusive, inclusive, and ambiguous. Other possible “we-use” alternatives such as “I” and other personal pronouns were used very rarely—if at all—in either section. These findings also suggest that the present tense was used more in article abstracts, but the present perfect tense was the most preferred tense in article conclusions. Both research and pedagogical implications are proffered and critically discussed.

Wang, S., Tseng, W.-T., & Johanson, R. (2021). To We or Not to We: Corpus-Based Research on First-Person Pronoun Use in Abstracts and Conclusions. SAGE Open, 11(2).

Here is an example of a descriptive abstract:

From the 1850s to the present, considerable criminological attention has focused on the development of theoretically-significant systems for classifying crime. This article reviews and attempts to evaluate a number of these efforts, and we conclude that further work on this basic task is needed. The latter part of the article explicates a conceptual foundation for a crime pattern classification system, and offers a preliminary taxonomy of crime.

Farr, K. A., & Gibbons, D. C. (1990). Observations on the Development of Crime Categories. International Journal of Offender Therapy and Comparative Criminology, 34(3), 223–237.

If you want to ensure your abstract is grammatically correct and easy to read, you can use ProWritingAid to edit it. The software integrates with Microsoft Word, Google Docs, and most web browsers, so you can make the most of it wherever you’re writing your paper.

Before you edit with ProWritingAid, make sure the suggestions you are seeing are relevant for your document by changing the document type to “Abstract” within the Academic writing style section.

You can use the Readability report to check your abstract for places to improve the clarity of your writing. Some suggestions might show you where to remove words, which is great if you’re over your word count.

We hope the five steps and examples we’ve provided help you write a great abstract for your research paper.

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Writing an abstract - a six point checklist (with samples)

Posted in: abstract , dissertations

The abstract is a vital part of any research paper. It is the shop front for your work, and the first stop for your reader. It should provide a clear and succinct summary of your study, and encourage your readers to read more. An effective abstract, therefore should answer the following questions:

• Why did you do this study or project?
• What did you do and how?
• What did you find?
• What do your findings mean?

So here's our run down of the key elements of a well-written abstract.

• Size - A succinct and well written abstract should be between approximately 100- 250 words.
• Background - An effective abstract usually includes some scene-setting information which might include what is already known about the subject, related to the paper in question (a few short sentences).
• Purpose  - The abstract should also set out the purpose of your research, in other words, what is not known about the subject and hence what the study intended to examine (or what the paper seeks to present).
• Methods - The methods section should contain enough information to enable the reader to understand what was done, and how. It should include brief details of the research design, sample size, duration of study, and so on.
• Results - The results section is the most important part of the abstract. This is because readers who skim an abstract do so to learn about the findings of the study. The results section should therefore contain as much detail about the findings as the journal word count permits.
• Conclusion - This section should contain the most important take-home message of the study, expressed in a few precisely worded sentences. Usually, the finding highlighted here relates to the primary outcomes of the study. However, other important or unexpected findings should also be mentioned. It is also customary, but not essential, to express an opinion about the theoretical or practical implications of the findings, or the importance of their findings for the field. Thus, the conclusions may contain three elements:
• The primary take-home message.
• Any additional findings of importance.
• Implications for future studies.

Example Abstract 2: Engineering Development and validation of a three-dimensional finite element model of the pelvic bone.

Abstract from: Dalstra, M., Huiskes, R. and Van Erning, L., 1995. Development and validation of a three-dimensional finite element model of the pelvic bone. Journal of biomechanical engineering, 117(3), pp.272-278.

And finally...  A word on abstract types and styles

Abstract types can differ according to subject discipline. You need to determine therefore which type of abstract you should include with your paper. Here are two of the most common types with examples.

Informative Abstract

The majority of abstracts are informative. While they still do not critique or evaluate a work, they do more than describe it. A good informative abstract acts as a surrogate for the work itself. That is, the researcher presents and explains all the main arguments and the important results and evidence in the paper. An informative abstract includes the information that can be found in a descriptive abstract [purpose, methods, scope] but it also includes the results and conclusions of the research and the recommendations of the author. The length varies according to discipline, but an informative abstract is usually no more than 300 words in length.

Descriptive Abstract A descriptive abstract indicates the type of information found in the work. It makes no judgements about the work, nor does it provide results or conclusions of the research. It does incorporate key words found in the text and may include the purpose, methods, and scope of the research. Essentially, the descriptive abstract only describes the work being summarised. Some researchers consider it an outline of the work, rather than a summary. Descriptive abstracts are usually very short, 100 words or less.

Adapted from Andrade C. How to write a good abstract for a scientific paper or conference presentation. Indian J Psychiatry. 2011 Apr;53(2):172-5. doi: 10.4103/0019-5545.82558. PMID: 21772657; PMCID: PMC3136027 .

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Dissertation Structure & Layout 101: How to structure your dissertation, thesis or research project.

By: Derek Jansen (MBA) Reviewed By: David Phair (PhD) | July 2019

So, you’ve got a decent understanding of what a dissertation is , you’ve chosen your topic and hopefully you’ve received approval for your research proposal . Awesome! Now its time to start the actual dissertation or thesis writing journey.

To craft a high-quality document, the very first thing you need to understand is dissertation structure . In this post, we’ll walk you through the generic dissertation structure and layout, step by step. We’ll start with the big picture, and then zoom into each chapter to briefly discuss the core contents. If you’re just starting out on your research journey, you should start with this post, which covers the big-picture process of how to write a dissertation or thesis .

*The Caveat *

In this post, we’ll be discussing a traditional dissertation/thesis structure and layout, which is generally used for social science research across universities, whether in the US, UK, Europe or Australia. However, some universities may have small variations on this structure (extra chapters, merged chapters, slightly different ordering, etc).

So, always check with your university if they have a prescribed structure or layout that they expect you to work with. If not, it’s safe to assume the structure we’ll discuss here is suitable. And even if they do have a prescribed structure, you’ll still get value from this post as we’ll explain the core contents of each section.  

Overview: S tructuring a dissertation or thesis

• Acknowledgements page
• Abstract (or executive summary)
• Table of contents , list of figures and tables
• Chapter 1: Introduction
• Chapter 2: Literature review
• Chapter 3: Methodology
• Chapter 4: Results
• Chapter 5: Discussion
• Chapter 6: Conclusion
• Reference list

As I mentioned, some universities will have slight variations on this structure. For example, they want an additional “personal reflection chapter”, or they might prefer the results and discussion chapter to be merged into one. Regardless, the overarching flow will always be the same, as this flow reflects the research process , which we discussed here – i.e.:

• The introduction chapter presents the core research question and aims .
• The literature review chapter assesses what the current research says about this question.
• The methodology, results and discussion chapters go about undertaking new research about this question.
• The conclusion chapter (attempts to) answer the core research question .

In other words, the dissertation structure and layout reflect the research process of asking a well-defined question(s), investigating, and then answering the question – see below.

To restate that – the structure and layout of a dissertation reflect the flow of the overall research process . This is essential to understand, as each chapter will make a lot more sense if you “get” this concept. If you’re not familiar with the research process, read this post before going further.

Right. Now that we’ve covered the big picture, let’s dive a little deeper into the details of each section and chapter. Oh and by the way, you can also grab our free dissertation/thesis template here to help speed things up.

The title page of your dissertation is the very first impression the marker will get of your work, so it pays to invest some time thinking about your title. But what makes for a good title? A strong title needs to be 3 things:

• Succinct (not overly lengthy or verbose)
• Specific (not vague or ambiguous)
• Representative of the research you’re undertaking (clearly linked to your research questions)

Typically, a good title includes mention of the following:

• The broader area of the research (i.e. the overarching topic)
• The specific focus of your research (i.e. your specific context)
• Indication of research design (e.g. quantitative , qualitative , or  mixed methods ).

For example:

A quantitative investigation [research design] into the antecedents of organisational trust [broader area] in the UK retail forex trading market [specific context/area of focus].

Again, some universities may have specific requirements regarding the format and structure of the title, so it’s worth double-checking expectations with your institution (if there’s no mention in the brief or study material).

Acknowledgements

This page provides you with an opportunity to say thank you to those who helped you along your research journey. Generally, it’s optional (and won’t count towards your marks), but it is academic best practice to include this.

So, who do you say thanks to? Well, there’s no prescribed requirements, but it’s common to mention the following people:

• Your dissertation supervisor or committee.
• Any professors, lecturers or academics that helped you understand the topic or methodologies.
• Any tutors, mentors or advisors.
• Your family and friends, especially spouse (for adult learners studying part-time).

There’s no need for lengthy rambling. Just state who you’re thankful to and for what (e.g. thank you to my supervisor, John Doe, for his endless patience and attentiveness) – be sincere. In terms of length, you should keep this to a page or less.

Abstract or executive summary

The dissertation abstract (or executive summary for some degrees) serves to provide the first-time reader (and marker or moderator) with a big-picture view of your research project. It should give them an understanding of the key insights and findings from the research, without them needing to read the rest of the report – in other words, it should be able to stand alone .

For it to stand alone, your abstract should cover the following key points (at a minimum):

• Your research questions and aims – what key question(s) did your research aim to answer?
• Your methodology – how did you go about investigating the topic and finding answers to your research question(s)?
• Your findings – following your own research, what did do you discover?
• Your conclusions – based on your findings, what conclusions did you draw? What answers did you find to your research question(s)?

So, in much the same way the dissertation structure mimics the research process, your abstract or executive summary should reflect the research process, from the initial stage of asking the original question to the final stage of answering that question.

In practical terms, it’s a good idea to write this section up last , once all your core chapters are complete. Otherwise, you’ll end up writing and rewriting this section multiple times (just wasting time). For a step by step guide on how to write a strong executive summary, check out this post .

Need a helping hand?

Table of contents

This section is straightforward. You’ll typically present your table of contents (TOC) first, followed by the two lists – figures and tables. I recommend that you use Microsoft Word’s automatic table of contents generator to generate your TOC. If you’re not familiar with this functionality, the video below explains it simply:

If you find that your table of contents is overly lengthy, consider removing one level of depth. Oftentimes, this can be done without detracting from the usefulness of the TOC.

Right, now that the “admin” sections are out of the way, its time to move on to your core chapters. These chapters are the heart of your dissertation and are where you’ll earn the marks. The first chapter is the introduction chapter – as you would expect, this is the time to introduce your research…

It’s important to understand that even though you’ve provided an overview of your research in your abstract, your introduction needs to be written as if the reader has not read that (remember, the abstract is essentially a standalone document). So, your introduction chapter needs to start from the very beginning, and should address the following questions:

• What will you be investigating (in plain-language, big picture-level)?
• Why is that worth investigating? How is it important to academia or business? How is it sufficiently original?
• What are your research aims and research question(s)? Note that the research questions can sometimes be presented at the end of the literature review (next chapter).
• What is the scope of your study? In other words, what will and won’t you cover ?
• How will you approach your research? In other words, what methodology will you adopt?
• How will you structure your dissertation? What are the core chapters and what will you do in each of them?

These are just the bare basic requirements for your intro chapter. Some universities will want additional bells and whistles in the intro chapter, so be sure to carefully read your brief or consult your research supervisor.

If done right, your introduction chapter will set a clear direction for the rest of your dissertation. Specifically, it will make it clear to the reader (and marker) exactly what you’ll be investigating, why that’s important, and how you’ll be going about the investigation. Conversely, if your introduction chapter leaves a first-time reader wondering what exactly you’ll be researching, you’ve still got some work to do.

Now that you’ve set a clear direction with your introduction chapter, the next step is the literature review . In this section, you will analyse the existing research (typically academic journal articles and high-quality industry publications), with a view to understanding the following questions:

• What does the literature currently say about the topic you’re investigating?
• Is the literature lacking or well established? Is it divided or in disagreement?
• How does your research fit into the bigger picture?
• How does your research contribute something original?
• How does the methodology of previous studies help you develop your own?

Depending on the nature of your study, you may also present a conceptual framework towards the end of your literature review, which you will then test in your actual research.

Again, some universities will want you to focus on some of these areas more than others, some will have additional or fewer requirements, and so on. Therefore, as always, its important to review your brief and/or discuss with your supervisor, so that you know exactly what’s expected of your literature review chapter.

Now that you’ve investigated the current state of knowledge in your literature review chapter and are familiar with the existing key theories, models and frameworks, its time to design your own research. Enter the methodology chapter – the most “science-ey” of the chapters…

In this chapter, you need to address two critical questions:

• Exactly HOW will you carry out your research (i.e. what is your intended research design)?
• Exactly WHY have you chosen to do things this way (i.e. how do you justify your design)?

Remember, the dissertation part of your degree is first and foremost about developing and demonstrating research skills . Therefore, the markers want to see that you know which methods to use, can clearly articulate why you’ve chosen then, and know how to deploy them effectively.

Importantly, this chapter requires detail – don’t hold back on the specifics. State exactly what you’ll be doing, with who, when, for how long, etc. Moreover, for every design choice you make, make sure you justify it.

In practice, you will likely end up coming back to this chapter once you’ve undertaken all your data collection and analysis, and revise it based on changes you made during the analysis phase. This is perfectly fine. Its natural for you to add an additional analysis technique, scrap an old one, etc based on where your data lead you. Of course, I’m talking about small changes here – not a fundamental switch from qualitative to quantitative, which will likely send your supervisor in a spin!

You’ve now collected your data and undertaken your analysis, whether qualitative, quantitative or mixed methods. In this chapter, you’ll present the raw results of your analysis . For example, in the case of a quant study, you’ll present the demographic data, descriptive statistics, inferential statistics , etc.

Typically, Chapter 4 is simply a presentation and description of the data, not a discussion of the meaning of the data. In other words, it’s descriptive, rather than analytical – the meaning is discussed in Chapter 5. However, some universities will want you to combine chapters 4 and 5, so that you both present and interpret the meaning of the data at the same time. Check with your institution what their preference is.

Now that you’ve presented the data analysis results, its time to interpret and analyse them. In other words, its time to discuss what they mean, especially in relation to your research question(s).

What you discuss here will depend largely on your chosen methodology. For example, if you’ve gone the quantitative route, you might discuss the relationships between variables . If you’ve gone the qualitative route, you might discuss key themes and the meanings thereof. It all depends on what your research design choices were.

Most importantly, you need to discuss your results in relation to your research questions and aims, as well as the existing literature. What do the results tell you about your research questions? Are they aligned with the existing research or at odds? If so, why might this be? Dig deep into your findings and explain what the findings suggest, in plain English.

The final chapter – you’ve made it! Now that you’ve discussed your interpretation of the results, its time to bring it back to the beginning with the conclusion chapter . In other words, its time to (attempt to) answer your original research question s (from way back in chapter 1). Clearly state what your conclusions are in terms of your research questions. This might feel a bit repetitive, as you would have touched on this in the previous chapter, but its important to bring the discussion full circle and explicitly state your answer(s) to the research question(s).

Next, you’ll typically discuss the implications of your findings? In other words, you’ve answered your research questions – but what does this mean for the real world (or even for academia)? What should now be done differently, given the new insight you’ve generated?

Lastly, you should discuss the limitations of your research, as well as what this means for future research in the area. No study is perfect, especially not a Masters-level. Discuss the shortcomings of your research. Perhaps your methodology was limited, perhaps your sample size was small or not representative, etc, etc. Don’t be afraid to critique your work – the markers want to see that you can identify the limitations of your work. This is a strength, not a weakness. Be brutal!

This marks the end of your core chapters – woohoo! From here on out, it’s pretty smooth sailing.

The reference list is straightforward. It should contain a list of all resources cited in your dissertation, in the required format, e.g. APA , Harvard, etc.

It’s essential that you use reference management software for your dissertation. Do NOT try handle your referencing manually – its far too error prone. On a reference list of multiple pages, you’re going to make mistake. To this end, I suggest considering either Mendeley or Zotero. Both are free and provide a very straightforward interface to ensure that your referencing is 100% on point. I’ve included a simple how-to video for the Mendeley software (my personal favourite) below:

Some universities may ask you to include a bibliography, as opposed to a reference list. These two things are not the same . A bibliography is similar to a reference list, except that it also includes resources which informed your thinking but were not directly cited in your dissertation. So, double-check your brief and make sure you use the right one.

The very last piece of the puzzle is the appendix or set of appendices. This is where you’ll include any supporting data and evidence. Importantly, supporting is the keyword here.

Your appendices should provide additional “nice to know”, depth-adding information, which is not critical to the core analysis. Appendices should not be used as a way to cut down word count (see this post which covers how to reduce word count ). In other words, don’t place content that is critical to the core analysis here, just to save word count. You will not earn marks on any content in the appendices, so don’t try to play the system!

Time to recap…

And there you have it – the traditional dissertation structure and layout, from A-Z. To recap, the core structure for a dissertation or thesis is (typically) as follows:

• Acknowledgments page

Most importantly, the core chapters should reflect the research process (asking, investigating and answering your research question). Moreover, the research question(s) should form the golden thread throughout your dissertation structure. Everything should revolve around the research questions, and as you’ve seen, they should form both the start point (i.e. introduction chapter) and the endpoint (i.e. conclusion chapter).

I hope this post has provided you with clarity about the traditional dissertation/thesis structure and layout. If you have any questions or comments, please leave a comment below, or feel free to get in touch with us. Also, be sure to check out the rest of the  Grad Coach Blog .

Psst... there’s more!

This post was based on one of our popular Research Bootcamps . If you're working on a research project, you'll definitely want to check this out ...

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36 Comments

many thanks i found it very useful

Glad to hear that, Arun. Good luck writing your dissertation.

Such clear practical logical advice. I very much needed to read this to keep me focused in stead of fretting.. Perfect now ready to start my research!

what about scientific fields like computer or engineering thesis what is the difference in the structure? thank you very much

Thanks so much this helped me a lot!

Very helpful and accessible. What I like most is how practical the advice is along with helpful tools/ links.

Thanks Ade!

Thank you so much sir.. It was really helpful..

You’re welcome!

Hi! How many words maximum should contain the abstract?

Thank you so much 😊 Find this at the right moment

You’re most welcome. Good luck with your dissertation.

best ever benefit i got on right time thank you

Many times Clarity and vision of destination of dissertation is what makes the difference between good ,average and great researchers the same way a great automobile driver is fast with clarity of address and Clear weather conditions .

I guess Great researcher = great ideas + knowledge + great and fast data collection and modeling + great writing + high clarity on all these

You have given immense clarity from start to end.

Morning. Where will I write the definitions of what I’m referring to in my report?

Thank you so much Derek, I was almost lost! Thanks a tonnnn! Have a great day!

Thanks ! so concise and valuable

This was very helpful. Clear and concise. I know exactly what to do now.

Thank you for allowing me to go through briefly. I hope to find time to continue.

Really useful to me. Thanks a thousand times

Very interesting! It will definitely set me and many more for success. highly recommended.

Thank you soo much sir, for the opportunity to express my skills

Usefull, thanks a lot. Really clear

Very nice and easy to understand. Thank you .

That was incredibly useful. Thanks Grad Coach Crew!

My stress level just dropped at least 15 points after watching this. Just starting my thesis for my grad program and I feel a lot more capable now! Thanks for such a clear and helpful video, Emma and the GradCoach team!

Do we need to mention the number of words the dissertation contains in the main document?

It depends on your university’s requirements, so it would be best to check with them 🙂

Such a helpful post to help me get started with structuring my masters dissertation, thank you!

Great video; I appreciate that helpful information

It is so necessary or avital course

This blog is very informative for my research. Thank you

Doctoral students are required to fill out the National Research Council’s Survey of Earned Doctorates

wow this is an amazing gain in my life

This is so good

How can i arrange my specific objectives in my dissertation?

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Organizing Research for Arts and Humanities Papers and Theses

• General Guide Information
• Developing a Topic
• What are Primary and Secondary Sources
• What are Scholarly and Non-Scholarly Sources
• Writing an Abstract
• Writing Academic Book Reviews
• Writing A Literature Review
• Using Images and other Media

What is an abstract?

Note: This description of a typical abstract and its elements is geared toward researchers in the arts and humanities. Additional information on writing abstracts is available in Dr. Robert Labaree's libguide on organizing research in the social sciences .

An abstract is a summary of a paper, a book, or a presentation. As a general rule, the abstract is written by the author of the work. Most abstracts are informative.

Abstracts are a required part of graduate theses and dissertations. Abstracts are common in academic and scholarly journal articles, as well as in conference presentations and publications of proceedings. The author, the title, and the abstract are the most immediately visible elements of a work of scholarship that other researchers see as they peruse scholarly databases and publications. These are also the elements that may be indexed by search engines such as Google.

Stylistic guidelines : Use active verbs, when possible, and write in complete sentences. Try to imagine yourself in the shoes of a reader who is not familiar with your work, and who might be reading the abstract to decide on the im portance and relevance of your research.

An informative abstract

A common type of abstract is informative. Such an abstract is usually about 300-500 words in length. It is usually composed after the conclusion of the writing of the work, and acts as a surrogate for the work itself.

Generally speaking an informative abstract should include at least the following elements:

1) an overall description of the topic explored;

2) the theoretical, historical, or methodological framework used;

3) an outline of the main argument(s);

4) a brief summary of the conclusion(s).

A descriptive abstract

A somewhat less common type of abstract is descriptive. Descriptive abstracts are short, ordinarily 150 words or less, and briefly describe the work, almost in an outline format.

Remember to keep track of your sources, regardless of the stage of your research. The USC Libraries have an excellent guide to  citation styles  and to  citation management software . 

• << Previous: What are Scholarly and Non-Scholarly Sources
• Next: Writing Academic Book Reviews >>
• Last Updated: Jan 19, 2023 3:12 PM
• URL: https://libguides.usc.edu/ah_writing

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How to Write a Dissertation Abstract

Last Updated: March 6, 2020 References

wikiHow is a “wiki,” similar to Wikipedia, which means that many of our articles are co-written by multiple authors. To create this article, volunteer authors worked to edit and improve it over time. This article has been viewed 23,121 times.

An abstract is a small summary of a larger paper. A dissertation is a long research paper with an original argument that you must write to graduate with a Master’s degree or doctorate. An abstract helps give your reader a map of your paper before he or she reads it. It also helps researchers to know if your paper will be helpful to them before they expend time reading it. Therefore, you should try to write as clear an abstract as possible, in simple and concise language.

Including the Necessary Information

• Start with your main thesis at the top.
• Next, read each section of your paper. As you read, write a one-sentence summary of each major chapter or section. Keep them in order on your paper. Regardless of your discipline, take time to point out the key theorists in the discipline you’ll be exploring in your paper.
• Include a summary of your conclusions, as well.
• If you’re writing an abstract for a scientific dissertation, it’s not necessary to include all of your literature review; however, you might include a sentence on how your paper fits into the larger academic discussion.

• Discuss how your research fits into the larger academic discussion.
• Talk about your methodology.
• Include your conclusions.
• Take time to discuss how it could lead to further research.

• Include any major works you’re analyzing. In other words, provide a short discussion of the source material, whether it’s the diaries of a famous historical figure for a history dissertation, a work of literature, a piece of music, or a great work of art.
• Discuss the major theories you’re applying to make your argument.
• Cover your main argument.
• Talk about your conclusions.

• Include any methodology you used to conduct research.
• Provide an overview of any studies you conducted, including participants and the purpose of the study.
• Discuss major theories that you are using for analyzing your work, as well as how your research fits into the larger discussion. Remember to keep it brief.
• Don’t forget to discuss your conclusions, as well as how your research could lead to further research.

• Include major theories you are using to analyze your research.
• Talk about your research methods, especially if you are collecting data.
• Provide specifics if you are looking at a particular company or analyzing a particular model.
• Discuss your overall conclusions.

Writing Your Abstract

• The name of the article you have written.
• Publication information, if there is any.

• Remember, you’re just trying to give your reader an overview of your dissertation, not every detail.

• You should also include the sentence about your conclusion.

• Remember, you are not just summarizing your individual thoughts in your abstract, you are recreating the argument you make in your paper in a shortened form.

• For instance, if you’re an archaeologist, you need to reference your primary materials.
• If you’re a librarian, you should talk about the methods you’ve used to collect your research.
• If you’re a psychologist, talk about the way you conducted your study.

• Only include information that is in the paper; do not bring new ideas into the abstract.

• The way you implement your research in science includes methodology (how you carried out your experiment), but in a humanities paper, you’ll likely be talking about the theories you applied in your research (such as applying Foucault’s theories to a book like Wuthering Heights).

Expert Q&A

• If you wrote a scientific, sociological, or psychological dissertation (or any other type of dissertation requiring field research), be sure to include information on your methodology. Thanks Helpful 0 Not Helpful 0
• If you’re writing an abstract on a literature paper, be sure to include the major works you’re reviewing. Thanks Helpful 0 Not Helpful 0
• You can use some technical language if it is a technical paper. Thanks Helpful 0 Not Helpful 0

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• ↑ http://www.sciencebuddies.org/science-fair-projects/project_abstract.shtml
• ↑ http://writingcenter.unc.edu/handouts/abstracts/
• ↑ http://libguides.usc.edu/content.php?pid=83009&sid=621164
• ↑ http://librarybissell.act.edu/content.php?pid=136789&sid=1171531
• ↑ http://users.ece.cmu.edu/~koopman/essays/abstract.html
• ↑ https://owl.english.purdue.edu/owl/resource/656/01/

About this article

To write a dissertation abstract, start with a condensed version of your thesis that's no more than 1 sentence long. Then, include sentences about the methodology you used for your research and any major points or theories you analyzed. You should also include a sentence about the conclusions you drew based on your research. In general, try to keep your dissertation abstract between 100 and 200 words. To learn how to use an outline of your dissertation to write your abstract, keep reading! Did this summary help you? Yes No

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Thesis and Dissertation Guide

• « Thesis & Dissertation Resources
• The Graduate School Home
• Introduction

Copyright Page

Dedication, acknowledgements, preface (optional), table of contents.

• List of Tables, Figures, and Illustrations

List of Abbreviations

List of symbols.

• Non-Traditional Formats
• Font Type and Size
• Spacing and Indentation
• Tables, Figures, and Illustrations
• Formatting Previously Published Work
• Internet Distribution
• Open Access
• Registering Copyright
• Using Copyrighted Materials
• Use of Your Own Previously Published Materials
• Submission Steps
• Submission Checklist
• Sample Pages

I. Order and Components

Please see the sample thesis or dissertation pages throughout and at the end of this document for illustrations. The following order is required for components of your thesis or dissertation:

• Dedication, Acknowledgements, and Preface (each optional)
• Table of Contents, with page numbers
• List of Tables, List of Figures, or List of Illustrations, with titles and page numbers (if applicable)
• List of Abbreviations (if applicable)
• List of Symbols (if applicable)
• Introduction, if any
• Main body, with consistent subheadings as appropriate
• Appendices (if applicable)
• Endnotes (if applicable)
• References (see section on References for options)

Many of the components following the title and copyright pages have required headings and formatting guidelines, which are described in the following sections.

Please consult the Sample Pages to compare your document to the requirements. A Checklist is provided to assist you in ensuring your thesis or dissertation meets all formatting guidelines.

The title page of a thesis or dissertation must include the following information:

• The title of the thesis or dissertation in all capital letters and centered 2″ below the top of the page.
• Your name, centered 1″ below the title. Do not include titles, degrees, or identifiers. The name you use here does not need to exactly match the name on your university records, but we recommend considering how you will want your name to appear in professional publications in the future.

Notes on this statement:

• When indicating your degree in the second bracketed space, use the full degree name (i.e., Doctor of Philosophy, not Ph.D. or PHD; Master of Public Health, not M.P.H. or MPH; Master of Social Work, not M.S.W. or MSW).
• List your department, school, or curriculum rather than your subject area or specialty discipline in the third bracketed space. You may include your subject area or specialty discipline in parentheses (i.e., Department of Romance Languages (French); School of Pharmacy (Molecular Pharmaceutics); School of Education (School Psychology); or similar official area).
• If you wish to include both your department and school names, list the school at the end of the statement (i.e., Department of Pharmacology in the School of Medicine).
• A dissertation submitted to the faculty at the University of North Carolina at Chapel Hill in partial fulfillment of the requirements for the degree of Doctor of Philosophy in the Department of Public Policy.
• A thesis submitted to the faculty at the University of North Carolina at Chapel Hill in partial fulfillment of the requirements for the degree of Master of Science in the School of Dentistry (Endodontics).
• A thesis submitted to the faculty at the University of North Carolina at Chapel Hill in partial fulfillment of the requirements for the degree of Master of Science in the Department of Nutrition in the Gillings School of Global Public Health.
• A dissertation submitted to the faculty at the University of North Carolina at Chapel Hill in partial fulfillment of the requirements for the degree of Doctor of Philosophy in the School of Education (Cultural Studies and Literacies).
• The words “Chapel Hill” must be centered 1″ below the statement.
• One single-spaced line below that, center the year in which your committee approves the completed thesis or dissertation. This need not be the year you graduate.
• Approximately 2/3 of the way across the page on the right-hand side of the page, 1″ below the year, include the phrase “Approved by:” (with colon) followed by each faculty member's name on subsequent double-spaced lines. Do not include titles such as Professor, Doctor, Dr., PhD, or any identifiers such as “chair” or “advisor” before or after any names. Line up the first letter of each name on the left under the “A” in the “Approved by:” line. If a name is too long to fit on one line, move this entire section of text slightly to the left so that formatting can be maintained.
• No signatures, signature lines, or page numbers should be included on the title page.

Include a copyright page with the following information single-spaced and centered 2″ above the bottom of the page:

© Year Author's Full Name (as it appears on the title page) ALL RIGHTS RESERVED

This page immediately follows the title page. It should be numbered with the lower case Roman numeral ii centered with a 1/2″ margin from the bottom edge.

Inclusion of this page offers you, as the author, additional protection against copyright infringement as it eliminates any question of authorship and copyright ownership. You do not need to file for copyright in order to include this statement in your thesis or dissertation. However, filing for copyright can offer other protections.

See Section IV for more information on copyrighting your thesis or dissertation.

Include an abstract page following these guidelines:

• Include the heading “ABSTRACT” in all capital letters, and center it 2″ below the top of the page.
• One double-spaced line below “ABSTRACT”, center your name, followed by a colon and the title of the thesis or dissertation. Use as many lines as necessary. Be sure that your name and the title exactly match the name and title used on the Title page.
• One single-spaced line below the title, center the phrase “(Under the direction of [advisor's name])”. Include the phrase in parentheses. Include the first and last name(s) of your advisor or formal co-advisors. Do not include the name of other committee members. Use the advisor's name only; do not include any professional titles such as PhD, Professor, or Dr. or any identifiers such as “chair” or “advisor”.
• Skip one double-spaced line and begin the abstract. The text of your abstract must be double-spaced and aligned with the document's left margin with the exception of indenting new paragraphs. Do not center or right-justify the abstract.
• Abstracts cannot exceed 150 words for a thesis or 350 words for a dissertation.
• Number the abstract page with the lower case Roman numeral iii (and iv, if more than one page) centered with a 1/2″ margin from the bottom edge.

Please write and proofread your abstract carefully. When possible, avoid including symbols or foreign words in your abstract, as they cannot be indexed or searched. Avoid mathematical formulas, diagrams, and other illustrative materials in the abstract. Offer a brief description of your thesis or dissertation and a concise summary of its conclusions. Be sure to describe the subject and focus of your work with clear details and avoid including lengthy explanations or opinions.

Your title and abstract will be used by search engines to help potential audiences locate your work, so clarity will help to draw the attention of your targeted readers.

You have an option to include a dedication, acknowledgements, or preface. If you choose to include any or all of these elements, give each its own page(s).

A dedication is a message from the author prefixed to a work in tribute to a person, group, or cause. Most dedications are short statements of tribute beginning with “To…” such as “To my family”.

Acknowledgements are the author's statement of gratitude to and recognition of the people and institutions that helped the author's research and writing.

A preface is a statement of the author's reasons for undertaking the work and other personal comments that are not directly germane to the materials presented in other sections of the thesis or dissertation. These reasons tend to be of a personal nature.

Any of the pages must be prepared following these guidelines:

• Do not place a heading on the dedication page.
• The text of short dedications must be centered and begin 2″ from the top of the page.
• Headings are required for the “ACKNOWLEDGEMENTS” and “PREFACE” pages. Headings must be in all capital letters and centered 2″ below the top of the page.
• The text of the acknowledgements and preface pages must begin one double-spaced line below the heading, be double-spaced, and be aligned with the document's left margin with the exception of indenting new paragraphs.
• Subsequent pages of text return to the 1″ top margin.
• The page(s) must be numbered with consecutive lower case Roman numerals (starting with the page number after the abstract) centered with a 1/2″ margin from the bottom edge.

Include a table of contents following these guidelines:

• Include the heading “TABLE OF CONTENTS” in all capital letters, and center it 2″ below the top of the page.
• Include one double-spaced line between the heading and the first entry.
• The table of contents should not contain listings for the pages that precede it, but it must list all parts of the thesis or dissertation that follow it.
• If relevant, be sure to list all appendices and a references section in your table of contents. Include page numbers for these items but do not assign separate chapter numbers.
• Entries must align with the document's left margin or be indented to the right of the left page margin using consistent tabs.
• Major subheadings within chapters must be included in the table of contents. The subheading(s) should be indented to the right of the left page margin using consistent tabs.
• If an entry takes up more than one line, break up the entry about three-fourths of the way across the page and place the rest of the text on a second line, single-spacing the two lines.
• Include one double-spaced line between each entry.
• Page numbers listed in the table of contents must be located just inside the right page margin with leaders (lines of periods) filling out the space between the end of the entry and the page number. The last digit of each number must line up on the right margin.
• Information included in the table of contents must match the headings, major subheadings, and numbering used in the body of the thesis or dissertation.
• The Table of Contents page(s) must be numbered with consecutive lower case Roman numerals centered with a 1/2″ margin from the bottom edge.

Lists of Tables, Figures, and Illustrations

If applicable, include a list of tables, list of figures, and/or list of illustrations following these guidelines:

• Include the heading(s) in all capital letters, centered 1″ below the top of the page.
• Each entry must include a number, title, and page number.
• Assign each table, figure, or illustration in your thesis or dissertation an Arabic numeral. You may number consecutively throughout the entire work (e.g., Figure 1, Figure 2, etc.), or you may assign a two-part Arabic numeral with the first number designating the chapter in which it appears, separated by a period, followed by a second number to indicate its consecutive placement in the chapter (e.g., Table 3.2 is the second table in Chapter Three).
• Numerals and titles must align with the document's left margin or be indented to the right of the left page margin using consistent tabs.
• Page numbers must be located just inside the right page margin with leaders (lines of periods) filling out the space between the end of the entry and the page number. The last digit of each number must line up on the right margin.
• Numbers, titles, and page numbers must each match the corresponding numbers, titles, and page numbers appearing in the thesis or dissertation.
• All Lists of Tables, Figures, and Illustrations page(s) must be numbered with consecutive lower case Roman numerals centered with a 1/2″ margin from the bottom edge.

If you use abbreviations extensively in your thesis or dissertation, you must include a list of abbreviations and their corresponding definitions following these guidelines:

• Include the heading “LIST OF ABBREVIATIONS” in all capital letters, and center it 1″ below the top of the page.
• Arrange your abbreviations alphabetically.
• Abbreviations must align with the document's left margin or be indented to the right of the left page margin using consistent tabs.
• If an entry takes up more than one line, single-space between the two lines.
• The List of Abbreviations page(s) must be numbered with consecutive lower case Roman numerals centered with a 1/2″ margin from the bottom edge.

If you use symbols in your thesis or dissertation, you may combine them with your abbreviations, titling the section “LIST OF ABBREVIATIONS AND SYMBOLS”, or you may set up a separate list of symbols and their definitions by following the formatting instructions above for abbreviations. The heading you choose must be in all capital letters and centered 1″ below the top of the page.

Previous: Introduction

Next: Format

How to Write a Good Abstract: Four Essential Elements with Example

This article shall guide you on how to write a good abstract. It lists the four essential elements of a good abstract, ideal number of words, and tense. The article ends with an example abstract of a real-life study with a supplemental video related to the findings.

After finishing your research paper, thesis, or scientific paper, there is a need for you to write the abstract. How is the abstract written? What are the essential elements of a good abstract?

If this is your first time, or you don’t feel confident about writing your first abstract, these tips are handy. I provide an example to demonstrate how it works.

Table of Contents

Why write the abstract.

Abstracts are indispensable references for scientists or students working on their research proposal; particularly, in preparing their literature review .

The information provided in the abstract must be sufficient to help the researcher decide whether the work is relevant to his or her interest or not. It should be brief but not lacking in essential elements to foster understanding of the research conducted. The abstract will also help the researcher decide whether to read the whole research paper or not.

Definition of an Abstract

An abstract is a summary of your research paper, thesis, or scientific paper. The abstract describes an unpublished or published research study in capsule form. It is a brief overview of the investigation so that researchers can comprehend the content of the research quickly. A good abstract is a mini-version of the whole research paper.

Four Essential Elements of a Good Abstract

So how should the abstract of a research paper be written so that readers will derive the maximum benefit from it?

In writing a good abstract, the critical sections of a research paper should be present. Generally, an informational abstract should sum up the main sections of the research paper, i.e., the introduction, the materials and methods used, the findings, discussion, conclusions, and recommendations. Therefore, it should contain the following essential elements:

1. Objective, aim, or purpose of the research paper

This part of the abstract mentions the study’s rationale. It states clearly the  objective , aim, or purpose of the study. It answers the question: “Why do we care about the issue?”

It states the problem statement or the central argument or  thesis statement . The relevance of the study in society is highlighted. Why did the researchers undertake the research? What is at stake?

2. Method or methodology that states the procedures used in the conduct of the study

The method or methodology part concisely describes the  method or methodology  employed in gathering the data, processing, and analysis. It gives a brief description of how the researcher or group of researchers performed the investigation. It includes the number of samples, instruments, and  statistical tests  used to analyze the data for quantitative researches. This part also gives a hint on the scope of the study.

This portion of the abstract tells us the perspective adopted by the researcher or researchers. It describes the types of evidence used.

The method or methodology part also mentions the key concepts, relevant keywords that make it distinct and searchable. It also describes the focus of the investigation, whether it is a group of people, a particular gender, race, community, environment, etc.

3. Results or major findings

This portion of the abstract summarizes the results or major findings of the study. It only states the significant results, most important ones, or highlights of the study in a sentence or a few sentences.

You can cite the probability values here to show the significance of computed correlations or differences. It emphasizes the practical importance of the findings; how those findings will add or enhance the body of knowledge on the issue.

4. Principal conclusion

This part of the research abstract states the principal conclusion of the study. After obtaining the findings, what did the researchers conclude?

The conclusion, in particular, should be given special attention in writing the abstract. The conclusion should be well supported by the findings of the investigation; not a sweeping statement without any valid argument or evidence to back it up. 

Other considerations in writing the research abstract

Do you need to include recommendations in the research abstract?

In practice, some academic institutions or scientific journals do not incorporate recommendations in the abstract. Browsing through some published scientific papers, I discovered that some abstracts end with only significant findings. While it would be good practice to have information as mentioned here, some deviations do exist.

As an academician, reading research abstracts that tell very little of the salient findings of the paper, particularly those behind a  paywall , causes frustration. I tend to think those abstracts work more as a marketing strategy rather than to disseminate important information.

For publicly-funded researches, where most researches almost always belong, withholding information for commercial gain, appears to be unethical or defeats the purpose of research. In the US,  taxpayers spend $140 billion every year  supporting research that they cannot access for free. That is why  open-access publishing  has gained popularity in recent years. However, authors still contend with the high costs of publication in open-access journals.

In truth, we can’t afford to be  free riders  as reliable and rigorous scientific publication requires time, money, and effort to produce. A candidate paper for publication requires intensive  peer review , editing, and formatting to make it worthy of publication in reputable journals. But perhaps publishing companies also need to be reasonable in their charges as many reviewers give their services for free.

Finally, the references (e.g. name of author and date) should not be cited in the abstract unless the research paper involves an improvement or modification of a previously published method used by a researcher.

Number of Words

Many references on how to write a good abstract recommend that it should be short. But how short should the research abstract be?

If you submit a paper for inclusion in a conference presentation, organizers usually limit its length from 250 to 300 words. It is possible, however, to capture the essence of the paper in a few sentences.

Hence, the challenge is how to make the research abstract as short as possible, without leaving out the essential elements, that will cause readers to read the paper. The abstract serves as a teaser, a taste of the pie for readers to decide whether they will read the whole piece.

Abstracts should not exceed 250 words, but this number could vary depending on the prescribed number of words, say when you would like to submit your research paper to a popular scientific journal. A good abstract adheres to brevity.

The limited number of words required for the research abstract means that every word included in the abstract is necessary and should be coherent. Important information should fit into one paragraph. This format requires a little bit of thinking and practice for the beginning researcher.

Tense of the Abstract

In what tense should the abstract be written?

The abstract is usually written in the past tense because the investigation has transpired. However, statement of facts in, say, the results and discussion and the conclusion, must be in the present tense.

In recent years, however, many authors write in the active tense. They use the first-person perspective in writing the paper. You can see the following phrases in the abstract:

• We analyze five years of sample visitor data…
• We compare non-linear, Poisson, and negative binomial count data…
• In this study, I challenge these interpretations…

Ultimately, the journal of publication defines the manner of abstract writing. But if you want the reader to grasp what you want to convey, bringing all the elements together would be more useful to the reader.

Example of an Abstract

I provide an example of a good abstract abiding with the precepts advanced in this article. It is for you to judge if this meets your expectations.

Young children’s exposure to violent computer games

This report discusses a two-year study on the effect of exposing four to six-year-old children to violent computer games. The study involved 200 children in nursery schools whose aggressive tendencies and anti-social behavior were observed with their teachers’ cooperation. The computer games they played at home were likewise assessed with the help of their parents. A strong correlation between violent computer game use and aggressive tendencies was obtained. Violent computer games, especially interactive ones, caused greater aggressiveness and anti-social behavior among children.

Although concisely written, the abstract captures the essence of the study. You can easily understand what transpired in that study, determine its relevance to your particular research, and decide whether to read the whole paper or merely cite the findings to strengthen your argument. But it always pays to read at least the method or methodology section of the full paper. While the study’s results are highly socially relevant, you might want to  critique the paper  by meticulously examining how the data was gathered and analyzed.

The example of an abstract given here is a real-life situation, as Dr. Perry Wilson reports in the following video.

Notice in the video that the study has its limitations. The participants, while young (8 to 12 years old), were conscious that they were observed in a university laboratory. This set-up may have affected their behavior.

Again, delving into the methodology of the study pays off. You cannot just blindly accept any scientific finding. It is always subject to error.

Final Notes

Have your style by deviating a little from the convention. The point is, the abstract should be interesting enough such that readers will want to read your investigation, learn from it, or skip it because it’s not directly relevant to their interest.

Since you want others to discover your work, select keywords or phrases that capture the essence of your research. Popular search engines like Chrome, Firefox, Microsoft Edge, or Safari need these keywords to effectively serve those who look for information on the issue that you cared to spend your time, money, and effort.

©P. A. Regoniel 9 November 2021

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Writing the abstract for your dissertation marks the final push towards the completion of a monumental academic endeavor. The abstract, a succinct summary of your lengthy work, is not just a formality but a crucial component that encapsulates your research's essence. Jessica from Scribbr is here to steer you through this critical task with practical steps and an illustrative example. Let's dive into the art of crafting an effective dissertation abstract that makes your research stand out.

What is an Abstract?

An abstract is a concise summary of a larger work, like a dissertation or a research paper, typically ranging between 150 to 300 words. It's vital to adhere to the specific requirements set by your university or intended journal regarding the abstract's length. Positioned on a separate page, the abstract precedes the main text in your dissertation, coming right after the title page and acknowledgements but before the table of contents.

Crafting Your Abstract: Essential Components

The purpose of your research.

Begin by defining the purpose of your research, addressing the practical or theoretical problem it solves or the question it aims to answer. Providing a brief context of your topic's relevance is crucial, but avoid delving into extensive background information.

Your Research Objectives

State your research objectives clearly, employing verbs like investigate , test , analyze , or evaluate to describe your actions precisely. Remember, this section should be penned in the present or past simple tense, steering clear of future tense since the research is concluded.

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Final Touches: Proofreading and Revising

After composing your abstract, it's imperative to proofread and revise it to ensure clarity and adherence to guidelines. Utilizing a professional proofreading service can help eliminate language errors, refine your structure, and enhance your academic style.

Crafting an abstract is the last step in the long journey of your dissertation writing. By following this guide, you'll be able to create a compelling and concise abstract that effectively communicates the core of your research. Remember, the abstract is often the first (and sometimes the only) part of your work that readers engage with, making it your chance to make a strong impression.

For further assistance and resources, including how to format an APA style abstract, visit Scribbr's official website . And don't forget to proofread and revise your abstract to perfection before submission. Now, take a deep breath, finalize that abstract, and step forward towards the completion of your academic milestone.

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Dibble’s Reduction Thesis: Implications for Global Lithic Analysis

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• Published: 07 May 2024
• Volume 7 , article number  12 , ( 2024 )

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Harold Dibble demonstrated the systematic effects of reduction by retouch upon the size and shape of Middle Paleolithic tools. The result was the reduction thesis, with its far-reaching implications for the understanding of Middle Paleolithic assemblage variation that even now are incompletely assimilated. But Dibble’s influence extended beyond the European Paleolithic. Others identified additional reduction methods and measures that complement Dibble’s reduction thesis, and applied analytical concepts and methods consistent with it to industries and assemblages around the world. These developments facilitated comprehensive reduction analysis of archaeological tools and assemblages and their comparison in the abstract despite the great diversity of their time–space contexts. Dibble argued that many assemblages are time-averaged accumulations. In cases from New Zealand to North America, methods he pioneered and that others extended reveal the complex processes by which behavior, tool use, curation, and time interacted to yield those accumulations. We are coming to understand that the record is no mere collection of ethnographic vignettes, instead a body of data that requires macroarchaeological approaches. Archaeology’s pending conceptual revolution in part is a legacy of Dibble’s thought.

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Around 1980, Harold Dibble began a career that examined sources of variation in Middle Paleolithic industries, mostly in France and southwest Asia. His untimely death in 2018 could not diminish the scale and impact of Dibble’s contributions to Paleolithic archaeology. Other contributors can testify to his stature in that field. As an archaeologist who cannot tell a Quina scraper from a chapeau de gendarme platform, my task is different: to sketch some of Dibble’s broader contributions to lithic analysis beyond Paleolithic studies, and especially to emphasize several current lines of thought and practice that at once derive in part from Dibble’s work but extend beyond it. This essay does not pretend to be comprehensive evaluation of Dibble’s oeuvre, merely to trace the extent of some of its parts, on the logic that a scholar’s work can be gauged partly by surveying how others use and expand it.

Experimental Controls and Key Variables in Fracture Mechanics

In a series of highly controlled experiments over several decades, Dibble and students demonstrated systematic effects of the fracture mechanics of reduction upon the size and shape of flakes struck from cores. Results synthesized by Li et al. ( 2023 ), this experimental program identified variables, mostly continuous, that were independent (e.g., platform dimensions) and dependent (e.g. length, mass or volume) in the fracture mechanics of flake production. The program established a framework for study of variation in flake size and shape. Experiments’ designs showed the limited effects of unobservable variables like angle and force of blow, suggesting that observable independent variables could predict original size of flake tools.

Results may seem narrow but these experiments had very broad implications indeed. By itself, inferring flake size and shape has modest value; for the great mass of unretouched flakes, it has none at all, because these dimensions can be measured directly and require no inference. But the results have great value in the study of flake tools that underwent resharpening between first use at larger size and discard at smaller size. In that context, Dibble’s experimental program identified independent or causal variables, again mostly continuous, like platform area and mathematically expressed their effects upon dependent continuous variables of size and shape. This insight made it possible to predict original flake size from properties like platform area that are retained on many retouched flakes. To the extent that flake tools were smaller at discard than experimental controls predicted, reduction from resharpening or other reasons is implicated. To the further extent that shape changed as size declined, variation in flake-tool shape may be a by-product of reduction, not a reflection of intended original form. Enter the reduction thesis.

The Reduction Thesis

With some ethnographic support (see citations in Dibble et al., 2017 :823), Dibble’s work showed that many—not all—stone tools varied substantially and systematically between first use and discard. Trivially, they only could become smaller, not larger, but tools and types varied greatly in degree and pattern of reduction experienced and the range of intermediate forms they took between first use and discard. Size and shape at discard are observable directly, but Dibble’s contribution was to demonstrate that, for many retouched tools, remnant unchanged segments of the original detached flake (e.g., platform variables) furnished estimates of original size. Thus, arose the reduction thesis (Shott, 2005 ; Iovita’s, 2009 :1448 “reversed ontogenies”).

Lithic analysts readily appreciate the importance of inferring original size of retouched and therefore reduced archaeological specimens. Again, by itself the knowledge is modest. But it looms larger in the context of Middle Paleolithic studies, where tool types were regarded as Platonic essences based on particular configurations of their form, and placement and extent of retouch qua reduction. Alternatively, as Dibble ( 1987 ) suggested, the pattern and degree of reduction by retouch allowed large flake tools to transit from what seemed one essential Middle Paleolithic type, often one or another variety of scraper, through a second, possibly to a third, and so on. For example, Middle Paleolithic backed knives experienced “transformations from one morphological Keilmesser form to another” (Jöris, 2009 :295) as a result of resharpening to maintain functional edges. If so, tool form at discard reflects not original design, least of all size, but “the last stages of a series of metamorphoses” (Jelinek, 1976 :27) of original form, as Dibble’s mentor put it. In this perspective, the ontological validity of essentialist Middle Paleolithic tool types is in doubt, and to some typology has passed from analytical to descriptive enterprise. Assuming that the form in which a tool was discarded was its intended, unchanging form is Davidson and Noble’s ( 1989 ) “finished-artefact fallacy,” rephrased by Dibble et al. as “the fallacy of the ‘desired end product’” (2017:814). In North American practice, it also has been called the “Frison effect” (Frison, 1968 ).

Dibble’s insight later was expanded in three respects:

The reduction thesis applied to cores as well as tools, for instance, in Dibble’s ( 1995 ) analysis of the Biache St.-Vaast Level IIA reduction sequence that demonstrated how core form and scar-patterning varied with their degree of working. (Throughout this essay, “reduction sequence” indicates the patterned ways that cobbles were reduced in the process of shaping them into tools or detaching flakes from them for use as tools, and subsequent reduction by retouch of core and flake tools, usage consistent with Dibble [e.g., 1995 :101]. This is not the place to address the contested issue of how or whether the reduction-sequence concept, originating over a century ago in North America, differs from the more recent and, in Paleolithic studies, more popular “ chaîne opératoire ”; interested readers may consult Shott [ 2003a ].)

It explained variation in Paleolithic flake-tool types besides scrapers, e.g., notched flakes (e.g., Bustos Pérez, 2020 ; Holdaway et al., 1996 ; Roebroeks et al., 1997 ). It also was applied to extensively or completely retouched, quasi-formal tools like Acheulean handaxes (McPherron, 1994 ) in Africa and Europe, European Middle Paleolithic bifaces (Serwatka, 2015 ) and Upper Paleolithic endscrapers (Morales, 2016 ), late Paleolithic core tools in Southeast Asia (Nguyen & Clarkson, 2016 ), Middle Stone Age Aterian points (Iovita, 2011 ) and Still Bay points (Archer et al., 2015 ) in Africa and unifacial and bifacial points in northern (Hiscock, 2009 :83) and western Australia (Maloney et al., 2017 ). Such analyses linked in the same tool-use and -reduction sequences what initially were defined as distinct types (e.g., Middle Paleolithic Keilmesser handaxes and leaf points [Serwatka, 2015 :19] and late Paleolithic core tools such that “various tool types are viewed as points or stages along a trajectory of continued reduction, rather than as discrete or separate types as in a segmented and discontinuous scheme” [Nguyen & Clarkson, 2016 :38]).

Largely implicit in Dibble’s work, reduction is or at least can be understood as a continuous process.

Expansion of the reduction thesis itself is significant in two further respects. First, it suggested the argument’s universal scope, the recognition that stone tools of all times and places can be subject to systematic transformations during use. What began, then, as an effort to understand variation in Middle Paleolithic flake tools might apply to stone-tool variation of any age, any industrial character, anywhere. In this perspective, the thesis can “put the analysis of tool’s live [sic] histories in a global and standardized framework to interpret the organization of past societies” (Morales, 2016 :243). Second, and starting from studies of Acheulean handaxes (McPherron, 1994 ), the reduction thesis engaged the concept of allometry to explain variation in stone tools. (Crompton and Gowlett introduced allometric analysis to Paleolithic research, defining allometry somewhat broadly, as “size-related variability” [1993:178]. No doubt suitable for their purposes, allometry is best understood as a biological concept—change in shape with change in size—and process that unfolds during growth to maturity. In lithic studies, obviously, the direction of size change is reversed; there, the allometric process unfolds during reduction. In biology where the concept originated and in lithic studies more generally, allometry measures the degree and strength of shape’s dependence upon size variation. Although Crompton and Gowlett found allometric variation at Kilombe, they explained it in functional, i.e., design, terms, not as the product of reduction.) Allometry is an inherently continuous process that requires measurement in continuous terms. Allometric variation certainly describes some aspects of the morphological transformations of Middle Paleolithic flake tools wrought by the reduction process. But it is especially pertinent to the analysis of extensively retouched tools, Paleolithic or otherwise, whose distinctive forms and time–space distributions make them markers of industries or cultures. Expansion of the reduction thesis, therefore, is particularly relevant in archaeological contexts that abound in such tools, not least the Americas.

Besides pertaining to many Paleolithic and other defined tool types and besides its invocation of allometry, the reduction thesis bears upon other theoretical and methodological matters. It engages the concept of tool curation and encompasses the methodology of tool failure or survivorship analysis. It has implications for long-term accumulations that help to disentangle the complexities of the formation of stone-tool assemblages. It begs—and can help answer—a deceptively complicated question about stone-tool quantification. Finally, it can contribute to the intellectual transformation that archaeology desperately needs, a “macroarchaeology” (Perreault, 2019 ) that eschews ethnographic dependency, studies archaeological units in their own terms with their own long durations and applies uniquely archaeological theory to explain their time–space variation. All of this from experiments on the fracture mechanics of flakes and their implications for Middle Paleolithic flake tools. The following sections untangle and address some threads of the reduction thesis.

The reduction thesis has far-reaching implications, one of course that concerns the integrity of French Middle Paleolithic scraper typology. Tool types from scrapers to notches may not be the Platonic essences sometimes assumed (e.g., like Dibble [ 1987 ], Bustos Pérez’s [ 2020 :Table 43] and Roebroeks et al.’s [ 1997 :148 and Figs. 17–18] observations that varieties of Middle Paleolithic scraper types transit via reduction to varieties of notch and denticulate types). If so, the reduction thesis reveals Middle Paleolithic Mousterian assemblage variation not as a chronicle of the “acrobatic manoeuvering of…typological tribes” (Clarke, 1973 :10) signaling their self-conscious identity by fixed tool form and assemblage composition as they alternate between rockshelters. Instead, variation might be a record of adaptive behavior, when freed of the constraint of subjectively defined “technocomplexes” (Monnier & Missal, 2014 ; cf. Faivre et al., 2017 ).

Significantly, Dibble’s thesis applies, as above, to more formal Paleolithic tools types and equally to other areas and research contexts. As examples of the reduction thesis’s even broader scope, Dibble’s argument echoes in the variation exhibited by Hoabinhian and other Southeast Asian industries (Marwick, 2008 ), in a comprehensive revision of the causes and meaning of variation in Australian flake tools (Hiscock & Attenbrow, 2005 ), in Hoffman’s ( 1986 ) concern that a range of Holocene North American point “types” defined using traditional approaches (what Maloney et al., 2017 :43 called “ad hoc” classification) capture merely various degrees of reduction of a single original type (reading Fig.  1 from Stages B to E; see Hamsa [ 2013 ] for a similar conclusion from a different sample in a different North American region), in New World Paleoindian points (Suárez & Cardillo, 2019 ; Thulman et al., 2023 ), and in the need to identify original sizes and shapes of distinct Holocene Patagonian point types whose forms converge in reduction (Charlin & Cardillo, 2018 ).

(Source: Hoffman, 1986 :Fig. 5)

Reduction’s effect upon typology. A single original bifacial tool type (far left) retouched in varying pattern and degree ( x -axis) yields several apparent “types” (far right)

Reduction as Continuum

If tools undergo continuous reduction then, ipso facto , reduction is a continuum. Increasingly, reduction’s continuous nature is assimilated to European Paleolithic practice, with productive results applied to flake tools (e.g., Iovita, 2009 ; Morales, 2016 :236; Serwatka, 2015 ). What goes for tools goes for debitage; since the reduction thesis arose, lithic analysts have modeled reduction’s entire span in continuous terms. Dibble’s work on these lines parallels, not presages, research elsewhere, particularly in North America. As there, he questioned typological approaches to flake analysis that involved subjective judgments of selected products and favored detailed measurements of full ranges of flake classes (e.g. Dibble, 1988 ). (See Shott, 2021 :57–70 on the comparative merits of typological and attribute methods in flake analysis.) By engaging the full range of materials in the Biache St.-Vaast Level IIA assemblage and recording dimensions and other continuous measures, for instance, Dibble ( 1995 ) showed that cores themselves exhibited systematic, size-related variation according to degree of reduction, and that resulting flakes also patterned by size regardless of the supposedly distinct types to which some of each were assigned. In this way, “Dibble was able to show that relying solely on scar pattern analysis of cores and some Levallois products was not suitable for studying the dynamics of a reduction strategy” (Wojtczak, 2014 :26). The continuous nature of this reduction process largely remained implicit in Dibble’s treatment, yet is apparent upon close reading.

Reduction sequences, that is, are continuous because the size, shape, and technological properties of cores and even unretouched flakes vary continuously along the reduction continuum from the first to last flake detached from a cobble. Some still question a continuous view of reduction, arguing for instance that “the dichotomy between ‘discrete’ vs. ‘continuous’ is difficult to place on neutral grounds – lithic scholars rarely come up with convincing means to evaluate the alternative to their preferred view” (Hussain, 2019 :243). This view relates stances—reduction as continuum or successive, discrete stages—to distinct ontological first principles incapable of comparative evaluation. Indeed, to some “Stage-like descriptions of technological choices are the hallmark of” traditional French systematics (Anghelinu et al., 2020 :35). If so, the question of reduction as continuous or staged becomes a matter of a priori predilection rather than reasoned inference, metaphysic more than logic.

Yet precisely such evaluations of competing alternatives have been made, testing a priori stances rather than merely choosing between them. Dibble ( 1988 ) tested a stage-based thesis of “predetermination” in Levallois reduction. He showed instead that a wide range of reduction products varied continuously among and between themselves, a result inconsistent with stage views. Analyzing experimental flake assemblages, Bradbury and Carr ( 1999 ) found no evidence for reduction “stages,” and expressed relative order of flake detachment (from 0 to 100% of core reduction) as a joint, continuous, function of faceting measures and flake size. A later study systematically tested key implications of both “stage” and “continuum” views in experimental data, again finding no support for the validity of stages and extensive support for the continuous alternative (Shott, 2017 ). A complementary approach supplements attribute recording with mass analysis and involves flake-size distributions that, in the same experimental assemblage, vary predictably between successive segments defined arbitrarily or, for instance, by change in hammer. When such assemblage segments hypothetically are “mixed” in various combinations, they model the mixing that characterizes empirical flake assemblages accumulating over long periods. Using suitable methods—in this case, constrained least-squares regression—the approach offers the prospect of disentangling—unmixing—empirical assemblage accumulations. Applied to two large North American Great Basin quarry assemblages, it identified mostly early but also intermediate segments of reduction that varied continuously across contexts and between assemblages (Shott, 2021 :98–103), complex mixing and variation that rigid “stage” approaches could neither detect nor characterize. Thus, individual reduction sequences and their products can be understood in continuous terms, as can the complex mixing of many reduction sequences in archaeological accumulations. Again, the continuous nature of the reduction process mostly was implicit in Dibble’s work, but clearly his approach paralleled those taken elsewhere and led to similar conclusions.

Allometry and Modularity

Typically, continuous flake-tool reduction produces allometry; some segments—usually distal and/or lateral edges—are reduced while others—usually butts or platforms–remain unchanged. Shape changes as size declines, i.e., allometry. Shape changes because various distinct segments— modules —of flakes are retouched to varying degrees or not at all. Hence, the reduction thesis views even humble flakes as composites of modular parts. Because it draws an analytical distinction between segments qua modules of flakes, the thesis encompasses allometry and modularity as latent properties, made explicit in recent applications of landmark-based geometric morphometrics (GM) to flake assemblages (Knell, 2022 ).

Allometry can be analyzed using tool dimensions like length and thickness (e.g., Crompton & Gowlett, 1993 ). Yet GM methods are particularly suited to analysis of allometry. GM itself is an innovative way to characterize and measure stone tools. GM methods are not “size-free” (cf. Caruana & Herries, 2021 :92) in the sense of separating all variation in size from all variation in shape. Rather, they separate shape variation that is independent of size from shape variation that is size-dependent (Shott & Otárola-Castillo, 2022 :95). As a result, GM methods can be instrumental to allometric analysis, not obstacles to it.

GM facilitates allometric analysis only by defining modules, segments of larger wholes whose landmarks vary more internally than they do with other modules of the same points. The modularity concept originated in biology, modules there comprising distinct anatomical segments like wings or limbs. As above, though, Dibble’s experiments and the reduction thesis arguably preadapted lithic analysis to receive it. Among Paleolithic flake tools, one salient modular distinction is between platforms, which may change little during use and retouch, and distal segments, which may be extensively retouched. Other modules can be defined and their correlations studied depending upon the research focus. In Western Hemisphere bifacial points, an equally salient distinction is between stems and blades as separate modules (e.g., Shott & Otárola-Castillo, 2022 ; Thulman et al., 2023 ), again not the only conceivable modular subdivisions. (For instance, Patagonian Bird Type IV-V points support a tip-versus-rest-of-point modularity [González-José & Charlin, 2012 ], and point margins also can function as modules.) In this perspective, allometry occurs by changing size proportions among modules as functions of overall specimen size. Archaeological GM analysis transforms stone tools from integral wholes to things of complementary parts—modular constructions—in complex interaction. In the process, it invokes a concept of modules implicit in Dibble’s experiments.

Curation and Its Distributions

Pattern and especially degree of reduction reflect the practice of curation. Originating with Binford ( 1973 ), the curation concept was (Hayden, 1976 ; Nash, 1996 ; Odell, 1996 )—still is, in some quarters—fraught with ambiguity. Yet a consensus has emerged that views curation as a continuous property of individual tools, not a categorical trait of entire assemblages or industries (e.g., Morales et al., 2015b :302). It expresses the ratio between realized and maximum utility (Shott, 1996 ), calculated in subjects like retouched stone tools as the difference between size at first use and at discard, usually on a 0–1 scale. Thus, curation of retouched flake tools scales as the difference between each tool’s size at detachment (or modification in preparation for first use) and at discard. As above, size at discard is a simple matter of observation but Dibble and colleagues’ experiments permitted inference to size at detachment. Hence, Dibble’s experimental results are key to the measurement of curation.

Again tools, not assemblages or industries, are curated (Shott, 1996 ), and specimens of a single type can be curated to varying degrees. Of course their original size, shape, and production technology are important properties of tools and their types. But the reduction thesis underscores the equal importance of the characteristic patterns and degrees of reduction that tools of any type experienced. Reduction is inherent in stone-tool curation, so must be measured. Analysts have devised a range of measures, mostly geometric or allometric (e.g., Morale et al.,  2015a ; Shott, 2005 ). So many reduction measures demand criteria for their evaluation (Hiscock & Tabrett, 2010 ) and, considering their diversity and varying statistical properties, may even reward synthesis as pooled or “multifactorial” measures derived from ordination methods (e.g. Shott & Seeman, 2017 ).

At any time, each person has a single value for age, trivially. The populations they comprise do not have discrete ages. But they can be characterized by their age distributions, the number or proportion of individuals at each age or pooled intervals of age from birth to greatest age. Similarly, each retouched tool has a single, individual, curation value. But when numbers of tools of any type are analyzed (types necessarily being defined before compiling curation distributions to avoid the mistake of conflating ranges of reduction and curation [e.g., the limited curation of “single scrapers” versus the more extensive curation of “double scrapers”] with distinct types), the resulting range and relative frequency of reduction values are population properties of the type. Ranging from unretouched to extensively reduced specimens, tools’ reduction values form curation distributions for the types. Such distributions plot the fate of any number x of specimens of a type similar or identical in original size and shape as they undergo varying patterns and degrees of reduction. Fractions of x experience discard at progressive intervals along the range of curation from larger original to smaller discarded size and shape. Across a range of specimens of the type, degree of reduction (ascending on the x-axis in Fig.  2 ) leaves fewer survivals (cumulative survivorship descending on the y-axis there). Figure  2 shows distributions for two variants of reduction indices computed from the same set of North American Paleoindian unifacial scrapers (LT1NP, LT2NP which, for illustration only, are treated here as separate distributions) and one for reduction of a replicate scraper (LTMorrow). (See Sahle & Negash, 2016 :Fig. 5 for similar distributions characterizing Ethiopian ethnographic scrapers.) Reduction distributions may indicate high (LT1NP) or comparatively low (LTMorrow) curation. Empirical distributions can reveal differences that certainly are continuous and sometimes are subtle.

(Source: Shott & Seeman, 2015 : Fig. 5)

Reduction distributions plotting cumulative survivorship (descending on y -axis) against degree of curation (ascending on x -axis). Upper, convex distribution (LT1NP) indicates high curation, most specimens surviving until they experience extensive reduction. Lower, less convex distribution (LT2NP) indicates lower curation by continuous degree, more specimens discarded at low to modest degree of reduction. Distribution of experimental replica (LTMorrow) indicates lowest curation by comparison

Whatever their form, curation distributions are properties of tool types no less integral than their original design (Iovita, 2009 ). The variation they exhibit itself has analytical value. For instance, reduction distributions correlate degree of utility extracted to varying hunting return rates, making curation a behavioral variable that tracks long-term adaptations (Miller, 2018 :55–63). They can be fitted to failure models like Weibull that gauge their scales and shapes and identify causes of discard in experimental assemblages (Lin et al., 2016 ), and among Upper Paleolithic Iberian endscrapers (Morales, 2016 ; Morales et al.,  2015b :302–303) and late Pleistocene North American scrapers (Shott & Seeman, 2017 ). Differences between distributions beg explanation, perhaps by industrial variation in Paleolithic assemblages or by changing access to toolstones, varying land-use scales or technological organization, changing population density or sociopolitical organization in assemblages anywhere. In this way, the reduction thesis creates variables by which to explain prehistoric behavior.

Assemblage Formation

Curation rate itself arguably measures relative use-life of tools (Shott, 1996 ). In turn, use-life is a key quantity in assemblage-formation models, along with tool-using activity rates and “mapping relations” (how types “map onto” functions or uses) (Ammerman & Feldman, 1974 ). Tool-use rates and “mapping relations” establish the functional or activity correlates of tool use. They contribute to assemblage variation, but are irrelevant in the following discussion that holds them constant in order to illustrate how curation and use-life alone can generate assemblage variation. Curation, which can be estimated in stone tools from the reduction thesis, and use-life thereby extend the reduction thesis’s scope beyond individual tools to the size and composition of entire assemblages as time-averaged accumulations.

Use-life is measured in time, and assemblages accumulate in time, a truism but one with important implications. Assemblage size increases, ceteris paribus , with time, therefore with accumulation span. But assemblage composition also changes as size increases, even holding tool-use activity rate and mapping relations constant, if tool types vary among themselves in use-life. How and why this occurs is explained elsewhere (e.g., Schiffer, 1975 ; Shott, 2010 ). Relevant here is that the composition of assemblages—presence or absence of and, if present, proportions of, various tool types—can vary strictly as a function of time and the accumulation of discarded specimens; assemblage size and composition are not always, possibly not often, independent quantities, composition instead changing with size up to an equilibrium point determined by the relationship between accumulation span and tool-type use-lives. When assemblage composition (as richness—number of types present—or other measures like heterogeneity) is plotted against assemblage size, either between assemblages or in bootstrap sampling within an assemblage, a positive linear relationship can result, up to the equilibrium point beyond which composition changes little. Before that point, assemblage composition has not stabilized for use-life and assemblage-size effects; beyond it, composition is stabilized with respect to those effects.

The reduction thesis bears directly upon assemblage formation only in helping to reveal types’ relative use-lives. But because the thesis demonstrates that some Paleolithic “types” like single scrapers are not types at all but merely modestly reduced versions of the legitimate type “flake tool,” indirectly it also helps explain some patterns of assemblage variation. For instance, assemblage size-composition correlations are documented in contexts as diverse as the French Middle Paleolithic (Shott, 2003b ), the North American Paleoindian (Shott, 2010 ) and late prehistoric New Zealand (Phillipps et al., 2022 ). As one example, Olduvai Paleolithic flake-tool “types” can, like Middle Paleolithic ones, be linked as segments of cobble reduction sequences (Potts, 1991 ); they are not legitimate types. Bootstrapped plots of richness, a composition measure, against number or size distinguish assemblages there whose size-composition relationships had stabilized (Fig.  3 a, FLK1-2) from those that had not (Fig.  3 b, HWK-1)(see Shott, 2003b :142–143 for similar treatment of French Middle Paleolithic assemblages).

Examples of bootstrap gauging of richness adequacy and standard deviation in Oldowan assemblages. a FLK1-2, adequate because empirical size is sufficient to stabilize richness and narrow standard deviation; b HWK-1, inadequate because richness fails to stabilize and standard deviation to narrow before reaching empirical size (Data source: Leakey, 1971 )

Similarly, Dibble argued that a Middle Paleolithic scraper’s “type” registers not its Platonic essence—single, double and convergent scrapers are not legitimate, distinct types but merely segments of the reduction continuum of the legitimate type “flake tool”–but its curation rate and, ceteris paribus , relative use-life (Lin, 2018 :1791). Dibble and Rolland ( 1992 :11) defined “intensity of occupations” in part as the ratio of Bordean scrapers to notches. In size-stabilized assemblages, Bordean single scrapers correlated inversely with the intensity ratio, double scrapers positively at high slope or rate, convergent ones positively at lower rate. The reduction thesis explains this size-composition pattern; single scrapers first must become double scrapers before they might become convergent ones. Both double and convergent scrapers can be transformed single scrapers, but double scrapers are transformed sooner because they form directly from single scrapers. As a joint probability of transformation-by-reduction first to double scraper and only later, possibly, to convergent scraper, a lower proportion of convergent scrapers is a highly probable arithmetic consequence of the reduction thesis. Scraper “types” considered as successive segments of a reduction continuum of a single flake-tool type increase proportionally in size-stabilized assemblages as measured by Dibble and Rolland’s scraper:notch ratio of occupational intensity because the ratio measures increasing scraper use and discard (Shott, 2003b :145 and Fig. 11.9). Recognition of such size-composition correlations also contributed to one of Dibble’s and colleagues’ later arguments (e.g., Dibble et al., 2017 ) that surface assemblages may be time-averaged palimpsests revisited as.

Quantification

Assimilating several components of the reduction thesis—its prevalence, resulting allometric variation, curation rates and their connection to use-life, and assemblage size-composition correlations—begs a question that appears trivial at first glance: how much is a tool? In limited respects, this question was broached years ago (e.g., Hiscock, 2002 ; Shott, 2000 ), chiefly to improve and standardize assemblage characterization for comparative analysis. Applied to a Syrian Middle Paleolithic assemblage, for instance, several measures of original number of specimens yielded generally concordant results, best among them considered total length of all intact and broken specimens combined divided by mean length of intact tools at discard (“TLV 1”) (Wojtczak, 2014 :63–72).

We regard tools as integral wholes not only for purposes of typological assignment and various analytical approaches, but also for counting. Leaving aside the fragmentation that further complicates quantification, for counting purposes one Quina scraper or one Early Side-notched (ESN) point, to use a North American example, is as much as another, no more or less: it’s one. But recognizing that many tools are subject to reduction of varying degree and pattern, whether or not they transit between types in any taxonomic system, we might change our perspective. A newly minted, large ESN point (Fig.  4 a) is, trivially an ESN point. But is it as much of an ESN point as a heavily resharpened stub (Fig.  4 e)? More? Less? Is the large, new point “one,” the reduced stub much less than one? Alternatively, is the latter, owing to its extensive use, more than one mint-condition ESN point? Questions so abstruse may seem unworthy of consideration. Yet if assemblages reflect, at least in part, patterns and frequencies of past activities, then not all ESN points register the same amount, or necessarily kind, of activity. For the study of original design, the specimen shown in Fig.  4 a is more than that shown in Fig.  4 e; as registers of use, Fig.  4 e is much more of a tool than is Fig.  4 a. The reduction thesis is essential to the calibration of tool occurrence to past design and behavior, in part by linking amount of use to degree or pattern of reduction.

(Source: Randall, 2002 :Fig. 4.2)

Reduction sequence of North American Early Side-notched points, a–e representing progressive intervals of reduction

• Macroarchaeology

Fitfully, archaeology is evolving as a scholarly discipline. In the mid-twentieth century, essentially it was culture history. Later, American archaeology became a functional or ecological anthropology, later still a postmodern critique of whatever postmodernists disliked, latterly a forum for identity construction and defense. Archaeology can be all of those things; it also can be a science of the human past, a possibility that encompasses at least part of all such approaches save postmodernism.

Dibble practiced a scientific archaeology, although not exactly as conceived by Perreault’s ( 2019 ) “macroarchaeology” that extensively revises the field’s ontology. Yet despite macroarchaeology’s breadth, even the limited domain of the reduction thesis and the study of stone tools bear upon it. For instance, objects like stone tools and their attributes are directly observable. But so trivial a statement obscures important implications. In macroarchaeological perspective, objects and the attributes they possess are “primary historical events” or units (Kitts, 1992 :136), of a time–space scale commensurate with individual observation and experience. Anyone can observe an object in production or use today, and lithic analysts can directly examine a prehistoric stone tool. The theory required to explain objects and their attributes, be it technological, functional, symbolic or social, and how they serve their broader cultural context, be it material (e.g., behavioral ecology), symbolic, structural, or social (e.g., agency, Marxism), is suitable to primary historical units, i.e., of a time–space scale commensurate with individual experience. Such theory explains the actions of individuals or social groups at moments or short intervals in time; it is historical (e.g., the movement of populations, the rise or decline of complex societies), material (e.g., environmental change, adaptation), or ethnographic. Little or none is unique to archaeology or its customary time–space scales.

Tool types are defined by repetitive patterning in attributes across specimens. Industries or assemblages of specimens of various types are defined by joint patterns of use and deposition. Types and industries or assemblages, and the cultures constructed from them, are bounded empirically by their time–space distributions. Types may occur over broad areas and persist for generations or longer, and their distribution at any moment surpasses the scale of individual experience. Pompeiis excepted, industries or assemblages are time-averaged over at least years, usually much longer. Neither types, assemblages, and cultures, or their time–space boundaries, are primary historical units. Types persist, and assemblages and industries accumulate, at time scales orders of magnitude greater than ethnographic or historical contexts. They are secondary historical events or units that “have no counterpart in the present…[and] are composed of primary events related in a spatial and temporal nexus” (Kitts, 1992 :137). As secondary units, types and assemblages possess properties that are emergent at the lower level of primary events—not deducible from the properties of units at that level—and that require “explanatory principles emergent with respect to” (Kitts, 1992 :142) them. Secondary units’ salient properties must be constructed from the material record. Units’ origins—how and why types or other secondary units arise, according to what causes–and behavior—their duration, changing incidence or distribution over that span, how and why they end, either by termination, transformation or branching—can be explained only by theory that pertains to their nature and time–space scales as secondary historical units. No other discipline has or needs such theory; archaeology has yet to develop it for its own purposes. Here lies its greatest challenge: conceiving the method and theory to define and explain the character and behavior of secondary historical units.

Perreault argued that the time–space scale that defined secondary historical units compromise the application of explanatory theory based on primary units, that the archaeological record was underdetermined by such theory (2019:29–32). Then he posed questions that limn the macroarchaeological challenge, some pertinent to lithic studies and the reduction thesis (2019:169–173). Merely as examples relevant in this context, macroarchaeological questions include the following examples. Do tool types or the industries they form and the reduction sequences that produced them trend in complexity over archaeological time? If so, why? Are types’ or industries’ rates of change related to that complexity, to population size, even to curation rate if, like biological taxa whose evolutionary rates are proportional to individual lifespan, higher curation implies fewer instances of replication? What explains why and how tool types, industries or other constructs originate and, crucially, why and how they end? No current theory–from behavioral ecology to evolutionary archaeology to any prehistoric equivalent of Annales to archaeology of the long term–approximates the macroarchaeological approach that Perreault advocates.

Of course macroarchaeology far surpasses the scope of the reduction thesis, which nevertheless has relevant implications for its development. The thesis promotes typological hygiene and thereby the definition of valid types qua secondary units. It distinguishes resharpening allometry and the modularity on which allometry rests from typological variation. Degree and pattern of allometry measure curation rate; the latter then becomes, as above, a continuous attribute of types as secondary units. Through its effect upon assemblage formation and accumulation (e.g., the size-composition effects noted above), the thesis links the composition of assemblages or industries as secondary units to the composition of tool inventories at the level of primary units.

Even if most of Dibble’s work did not attempt the shift in scale and focus that Perreault’s macroarchaeology entails—no one has, to this point—he helped establish knowable, replicable—positivist—foundations for scientific inference from the material record. And Dibble et al.’s ( 2017 ) accumulations view takes a limited macroarchaeological perspective on the formation and transformation of assemblages. Until macroarchaeology prevails, we will continue to define the wrong units at the wrong scales whose nature and behavior we try to explain using the wrong theory. The reduction thesis has a role, admittedly modest, in this necessary transformation.

Reception of the Reduction Thesis

The reduction thesis rejects the view of Paleolithic tool types as Platonic essences. Being a powerful explanation for considerable variation in lithic industries and assemblages, as sketched above, it has earned broad if uneven acceptance, particularly in New World and Australian archaeology. Ironically, that reception is conspicuously uneven in European Paleolithic archaeology, where the thesis originated. If to some there the reduction thesis is “reasonably demonstrated” (Anghelinu et al., 2020 :37), others dismiss or ignore it. Despite noteworthy exceptions, my outsider’s impression is that many, possibly most, European Paleolithic scholars remain unpersuaded by, or indifferent to, the reduction thesis and its far-reaching implications for our understanding of the past.

No doubt the number of such scholars and the breadth of their practice surpass any simplistic opposition between views of Paleolithic tool types as Platonic essences or mere domains of nominal variation (Marwick, 2008 :109), of French versus American paradigms (Clark, 2002 ), of Bordes’s facies qua cultures versus Binford’s toolkits. Nor can an outsider like me command the relevant literature or be attuned to possibly subtle changes in approach or ontology in Paleolithic studies. But even recent efforts to reconcile or synthesize approaches betray a strong predisposition toward essentialism (e.g., Hussain, 2019 ; Reynolds, 2020 :193; cf. Anghelinu et al., 2020 , whose attempt at synthesis deserves close study). Even if, then, Dibble’s reduction thesis is a figurative prophet with highly uneven honor in its field of origin, it has transformed the analysis of stone tools in other contexts.

One Recent Example of Dibble’s Influence

Many Dibble students and colleagues are recognizable by the nature and quality of their work, itself one of his greatest legacies; you know who you are, Holdaway, Iovita, Li, Lin, McPherron, Monnier, Olszewski, Rezek and others. But Dibble influenced many more.

As one example among many, my current collaborative project involves GM allometric analysis of a fairly large sample—over 5000—midcontinental North American points catalogued from private collections that form a time sequence that spans more than 10,000 years of prehistory (Nolan et al., 2022 ). The reduction thesis and its implications, sketched above, are integral to our analytical approach. We can chart time trends in curation rates, allometric trajectories and degrees of modularity and integration in our dataset (e.g., Shott et al., 2023 ), and relate these properties of secondary historical types to environmental, demographic, or sociopolitical trends at suitable time–space scales. Certainly in its current form, this project would be inconceivable without Dibble’s work. In prehistoric archaeology, Dibble’s influence extends well beyond the Old World Paleolithic. In theoretical terms, it extends well beyond the fracture mechanics of brittle solids.

This essay began with flakes and ended at some of the greatest ontological challenges confronting archaeology today. In the process, it discussed other archaeologists’ practice as much as Dibble’s. That is at once deliberate and meant as praise. Dibble’s own interests lay in important details of fracture mechanics and in Middle Paleolithic archaeology, as well as field-recording and database management. Yet implications of his work were explored and elaborated in time–space contexts that far surpass the Middle Paleolithic. Today, we can devise reduction measures suitable to a range of tool types and practice typological hygiene by distinguishing continuous or categorical variation between types from continuous allometric reduction variation within them. We can gauge that allometric variation in the context of varying integration of modular segments of stone tools. We can derive curation distributions, measure their properties in detail and compare variation among types or periods. We can begin to probe the complexities of assemblage formation, the persistent correlation between assemblage size and composition. We can pose and begin to address deceptively profound questions like “How much is a tool?”. We even can contemplate needed, macroarchaeological, revisions to the field’s ontology. We can do these things and more in part because of Dibble’s work with his students and colleagues. Not a bad legacy, that.

Data Availability

Not applicable.

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Acknowledgements

My thanks to Gilliane Monnier and Shannon McPherron for the kind invitation to participate in the Society for American Archaeology symposium from which this essay derived. The editor and three anonymous reviewers helped clarify important points. A. Randall kindly permitted use of Figure 4 . Of course the essay is dedicated to Harold Dibble, for his many contributions to lithic analysis.

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M.S. wrote the manuscript text, prepared Figures 1-4, and reviewed the ms.

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Shott, M.J. Dibble’s Reduction Thesis: Implications for Global Lithic Analysis. J Paleo Arch 7 , 12 (2024). https://doi.org/10.1007/s41982-024-00178-y

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Accepted : 06 April 2024

Published : 07 May 2024

DOI : https://doi.org/10.1007/s41982-024-00178-y

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