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Exploratory Research – Types, Methods and Examples

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Exploratory Research

Definition:

Exploratory research is a type of research design that is used to investigate a research question when the researcher has limited knowledge or understanding of the topic or phenomenon under study.

The primary objective of exploratory research is to gain insights and gather preliminary information that can help the researcher better define the research problem and develop hypotheses or research questions for further investigation.

Exploratory Research Methods

There are several types of exploratory research, including:

Literature Review

This involves conducting a comprehensive review of existing published research, scholarly articles, and other relevant literature on the research topic or problem. It helps to identify the gaps in the existing knowledge and to develop new research questions or hypotheses.

Pilot Study

A pilot study is a small-scale preliminary study that helps the researcher to test research procedures, instruments, and data collection methods. This type of research can be useful in identifying any potential problems or issues with the research design and refining the research procedures for a larger-scale study.

This involves an in-depth analysis of a particular case or situation to gain insights into the underlying causes, processes, and dynamics of the issue under investigation. It can be used to develop a more comprehensive understanding of a complex problem, and to identify potential research questions or hypotheses.

Focus Groups

Focus groups involve a group discussion that is conducted to gather opinions, attitudes, and perceptions from a small group of individuals about a particular topic. This type of research can be useful in exploring the range of opinions and attitudes towards a topic, identifying common themes or patterns, and generating ideas for further research.

Expert Opinion

This involves consulting with experts or professionals in the field to gain their insights, expertise, and opinions on the research topic. This type of research can be useful in identifying the key issues and concerns related to the topic, and in generating ideas for further research.

Observational Research

Observational research involves gathering data by observing people, events, or phenomena in their natural settings to gain insights into behavior and interactions. This type of research can be useful in identifying patterns of behavior and interactions, and in generating hypotheses or research questions for further investigation.

Open-ended Surveys

Open-ended surveys allow respondents to provide detailed and unrestricted responses to questions, providing valuable insights into their attitudes, opinions, and perceptions. This type of research can be useful in identifying common themes or patterns, and in generating ideas for further research.

Data Analysis Methods

Exploratory Research Data Analysis Methods are as follows:

Content Analysis

This method involves analyzing text or other forms of data to identify common themes, patterns, and trends. It can be useful in identifying patterns in the data and developing hypotheses or research questions. For example, if the researcher is analyzing social media posts related to a particular topic, content analysis can help identify the most frequently used words, hashtags, and topics.

Thematic Analysis

This method involves identifying and analyzing patterns or themes in qualitative data such as interviews or focus groups. The researcher identifies recurring themes or patterns in the data and then categorizes them into different themes. This can be helpful in identifying common patterns or themes in the data and developing hypotheses or research questions. For example, a thematic analysis of interviews with healthcare professionals about patient care may identify themes related to communication, patient satisfaction, and quality of care.

Cluster Analysis

This method involves grouping data points into clusters based on their similarities or differences. It can be useful in identifying patterns in large datasets and grouping similar data points together. For example, if the researcher is analyzing customer data to identify different customer segments, cluster analysis can be used to group similar customers together based on their demographic, purchasing behavior, or preferences.

Network Analysis

This method involves analyzing the relationships and connections between data points. It can be useful in identifying patterns in complex datasets with many interrelated variables. For example, if the researcher is analyzing social network data, network analysis can help identify the most influential users and their connections to other users.

Grounded Theory

This method involves developing a theory or explanation based on the data collected during the exploratory research process. The researcher develops a theory or explanation that is grounded in the data, rather than relying on pre-existing theories or assumptions. This can be helpful in developing new theories or explanations that are supported by the data.

Applications of Exploratory Research

Exploratory research has many practical applications across various fields. Here are a few examples:

• Marketing Research : In marketing research, exploratory research can be used to identify consumer needs, preferences, and behavior. It can also help businesses understand market trends and identify new market opportunities.
• Product Development: In product development, exploratory research can be used to identify customer needs and preferences, as well as potential design flaws or issues. This can help companies improve their product offerings and develop new products that better meet customer needs.
• Social Science Research: In social science research, exploratory research can be used to identify new areas of study, as well as develop new theories and hypotheses. It can also be used to identify potential research methods and approaches.
• Healthcare Research : In healthcare research, exploratory research can be used to identify new treatments, therapies, and interventions. It can also be used to identify potential risk factors or causes of health problems.
• Education Research: In education research, exploratory research can be used to identify new teaching methods and approaches, as well as identify potential areas of study for further research. It can also be used to identify potential barriers to learning or achievement.

Examples of Exploratory Research

Here are some more examples of exploratory research from different fields:

• Social Science : A researcher wants to study the experience of being a refugee, but there is limited existing research on this topic. The researcher conducts exploratory research by conducting in-depth interviews with refugees to better understand their experiences, challenges, and needs.
• Healthcare : A medical researcher wants to identify potential risk factors for a rare disease but there is limited information available. The researcher conducts exploratory research by reviewing medical records and interviewing patients and their families to identify potential risk factors.
• Education : A teacher wants to develop a new teaching method to improve student engagement, but there is limited information on effective teaching methods. The teacher conducts exploratory research by reviewing existing literature and interviewing other teachers to identify potential approaches.
• Technology : A software developer wants to develop a new app, but is unsure about the features that users would find most useful. The developer conducts exploratory research by conducting surveys and focus groups to identify user preferences and needs.
• Environmental Science : An environmental scientist wants to study the impact of a new industrial plant on the surrounding environment, but there is limited existing research. The scientist conducts exploratory research by collecting and analyzing soil and water samples, and conducting interviews with residents to better understand the impact of the plant on the environment and the community.

How to Conduct Exploratory Research

Here are the general steps to conduct exploratory research:

• Define the research problem: Identify the research problem or question that you want to explore. Be clear about the objective and scope of the research.
• Review existing literature: Conduct a review of existing literature and research on the topic to identify what is already known and where gaps in knowledge exist.
• Determine the research design : Decide on the appropriate research design, which will depend on the nature of the research problem and the available resources. Common exploratory research designs include case studies, focus groups, interviews, and surveys.
• Collect data: Collect data using the chosen research design. This may involve conducting interviews, surveys, or observations, or collecting data from existing sources such as archives or databases.
• Analyze data: Analyze the data collected using appropriate qualitative or quantitative techniques. This may include coding and categorizing qualitative data, or running descriptive statistics on quantitative data.
• I nterpret and report findings: Interpret the findings of the analysis and report them in a way that is clear and understandable. The report should summarize the findings, discuss their implications, and make recommendations for further research or action.
• Iterate : If necessary, refine the research question and repeat the process of data collection and analysis to further explore the topic.

When to use Exploratory Research

Exploratory research is appropriate in situations where there is limited existing knowledge or understanding of a topic, and where the goal is to generate insights and ideas that can guide further research. Here are some specific situations where exploratory research may be particularly useful:

• New product development: When developing a new product, exploratory research can be used to identify consumer needs and preferences, as well as potential design flaws or issues.
• Emerging technologies: When exploring emerging technologies, exploratory research can be used to identify potential uses and applications, as well as potential challenges or limitations.
• Developing research hypotheses: When developing research hypotheses, exploratory research can be used to identify potential relationships or patterns that can be further explored through more rigorous research methods.
• Understanding complex phenomena: When trying to understand complex phenomena, such as human behavior or societal trends, exploratory research can be used to identify underlying patterns or factors that may be influencing the phenomenon.
• Developing research methods : When developing new research methods, exploratory research can be used to identify potential issues or limitations with existing methods, and to develop new methods that better capture the phenomena of interest.

Purpose of Exploratory Research

The purpose of exploratory research is to gain insights and understanding of a research problem or question where there is limited existing knowledge or understanding. The objective is to explore and generate ideas that can guide further research, rather than to test specific hypotheses or make definitive conclusions.

Exploratory research can be used to:

• Identify new research questions: Exploratory research can help to identify new research questions and areas of inquiry, by providing initial insights and understanding of a topic.
• Develop hypotheses: Exploratory research can help to develop hypotheses and testable propositions that can be further explored through more rigorous research methods.
• Identify patterns and trends : Exploratory research can help to identify patterns and trends in data, which can be used to guide further research or decision-making.
• Understand complex phenomena: Exploratory research can help to provide a deeper understanding of complex phenomena, such as human behavior or societal trends, by identifying underlying patterns or factors that may be influencing the phenomena.
• Generate ideas: Exploratory research can help to generate new ideas and insights that can be used to guide further research, innovation, or decision-making.

Characteristics of Exploratory Research

The following are the main characteristics of exploratory research:

• Flexible and open-ended : Exploratory research is characterized by its flexible and open-ended nature, which allows researchers to explore a wide range of ideas and perspectives without being constrained by specific research questions or hypotheses.
• Qualitative in nature : Exploratory research typically relies on qualitative methods, such as in-depth interviews, focus groups, or observation, to gather rich and detailed data on the research problem.
• Limited scope: Exploratory research is generally limited in scope, focusing on a specific research problem or question, rather than attempting to provide a comprehensive analysis of a broader phenomenon.
• Preliminary in nature : Exploratory research is preliminary in nature, providing initial insights and understanding of a research problem, rather than testing specific hypotheses or making definitive conclusions.
• I terative process : Exploratory research is often an iterative process, where the research design and methods may be refined and adjusted as new insights and understanding are gained.
• I nductive approach : Exploratory research typically takes an inductive approach to data analysis, seeking to identify patterns and relationships in the data that can guide further research or hypothesis development.

Advantages of Exploratory Research

The following are some advantages of exploratory research:

• Provides initial insights: Exploratory research is useful for providing initial insights and understanding of a research problem or question where there is limited existing knowledge or understanding. It can help to identify patterns, relationships, and potential hypotheses that can guide further research.
• Flexible and adaptable : Exploratory research is flexible and adaptable, allowing researchers to adjust their methods and approach as they gain new insights and understanding of the research problem.
• Qualitative methods : Exploratory research typically relies on qualitative methods, such as in-depth interviews, focus groups, and observation, which can provide rich and detailed data that is useful for gaining insights into complex phenomena.
• Cost-effective : Exploratory research is often less costly than other research methods, such as large-scale surveys or experiments. It is typically conducted on a smaller scale, using fewer resources and participants.
• Useful for hypothesis generation : Exploratory research can be useful for generating hypotheses and testable propositions that can be further explored through more rigorous research methods.
• Provides a foundation for further research: Exploratory research can provide a foundation for further research by identifying potential research questions and areas of inquiry, as well as providing initial insights and understanding of the research problem.

Limitations of Exploratory Research

The following are some limitations of exploratory research:

• Limited generalizability: Exploratory research is typically conducted on a small scale and uses non-random sampling techniques, which limits the generalizability of the findings to a broader population.
• Subjective nature: Exploratory research relies on qualitative methods and is therefore subject to researcher bias and interpretation. The findings may be influenced by the researcher’s own perceptions, beliefs, and assumptions.
• Lack of rigor: Exploratory research is often less rigorous than other research methods, such as experimental research, which can limit the validity and reliability of the findings.
• Limited ability to test hypotheses: Exploratory research is not designed to test specific hypotheses, but rather to generate initial insights and understanding of a research problem. It may not be suitable for testing well-defined research questions or hypotheses.
• Time-consuming : Exploratory research can be time-consuming and resource-intensive, particularly if the researcher needs to gather data from multiple sources or conduct multiple rounds of data collection.
• Difficulty in interpretation: The open-ended nature of exploratory research can make it difficult to interpret the findings, particularly if the researcher is unable to identify clear patterns or relationships in the data.

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Muhammad Hassan

Researcher, Academic Writer, Web developer

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• Citation Styles

How to write an exploratory essay [Updated 2023]

Unlike other types of essays, the exploratory essay does not present a specific argument or support a claim with evidence. Instead, an exploratory essay allows a writer to "explore" a topic and consider tentative conclusions about it. This article covers what you need to know to write a successful exploratory essay.

What is an exploratory essay?

An exploratory essay considers a topic or problem and explores possible solutions. This type of paper also sometimes includes background about how you have approached the topic, as well as information about your research process.

Whereas other types of essays take a concrete stance on an issue and offer extensive support for that stance, the exploratory essay covers how you arrived at an idea and what research materials and methods you used to explore it.

For example, an argumentative essay on expanding public transportation might argue that increasing public transit options improves citizens' quality of life. However, an exploratory essay would provide context for the issue and discuss what data and research you gathered to consider the problem.

What to include in an exploratory essay

Importantly, an exploratory essay does not reach a specific conclusion about a topic. Rather, it explores multiple conclusions and possibilities. So, for the above example, your exploratory essay might include several viewpoints about public transit, including research from urban planners, transportation advocates, and other experts.

Finally, an exploratory essay will include some reflection on your own research and writing process. You might be asked to draw some conclusions about how you could tackle your topic in an argumentative essay or you might reflect on what sources or pieces of evidence were most helpful as you were exploring the topic.

Ultimately, the primary goal of an exploratory essay is to make an inquiry about a topic or problem, investigate the context, and address possible solutions.

What to expect in an exploratory essay assignment

This section discusses what you can expect in an exploratory essay assignment, in terms of length, style, and sources. Instructors may also provide you with an exploratory essay example or an assignment rubric to help you determine if your essay meets the appropriate guidelines .

The expected length of an exploratory essay varies depending on the topic, course subject, and course level. For instance, an exploratory essay assigned in an upper-level sociology course will likely be longer than a similar assignment in an introductory course.

Like other essay types, exploratory essays typically include at least five paragraphs, but most range from a few pages to the length of a full research paper .

While exploratory essays will generally follow academic style guidelines, they differ from other essays because they tend to utilize a more reflective, personal tone. This doesn't mean that you can cast off academic style rules, however.

Rather, think of an exploratory essay as a venue for presenting your topic and methods to a sympathetic and intelligent audience of fellow researchers. Most importantly, make sure that your writing is clear, correct, and concise.

As an exploration of your approach to a topic, an exploratory essay will necessarily incorporate research material. As a result, you should expect to include a bibliography or references page with your essay. This page will list both the sources that you cite in your essay, as well as any sources that you may have consulted during your research process.

The citation style of your essay's bibliography will vary based on the subject of the course. For example, an exploratory essay for a sociology class will probably adhere to APA style , while an essay in a history class might use Chicago style .

Exploratory essay outline and format

An exploratory essay utilizes the same basic structure that you'll find in other essays. It includes an introduction, body paragraphs, and a conclusion. The introduction sets up the context for your topic, addresses why that topic is worthy of study, and states your primary research question(s).

The body paragraphs cover the research that you've conducted and often include overviews of the sources that you've consulted. The conclusion returns to your research question and considers possible solutions.

• Introduction

The introduction of an exploratory essay functions as an overview. In this section, you should provide context for your topic, explain why the topic is important, and state your research question:

• Context includes general information about the topic. This part of the introduction may also outline, or signpost, what the rest of the paper will cover.
• Topic importance helps readers "buy in" to your research. A few sentences that address the question, "so what?" will enable you to situate your research within an ongoing debate.
• The last part of of your introduction should clearly state your research question. It's okay to have more than one, depending on the assignment.

If you were writing an exploratory essay on public transportation, you might start by briefly introducing the recent history of public transit debates. Next, you could explain that public transportation research is important because it has a concrete impact on our daily lives. Finally, you might end your introduction by articulating your primary research questions.

While some individuals may choose not to utilize public transportation, decisions to expand or alter public transit systems affect the lives of all. As a result of my preliminary research, I became interested in exploring whether public transportation systems improve citizens' quality of life. In particular, does public transit only improve conditions for those who regularly use these systems? Or, do improvements in public transportation positively impact the quality of life for all individuals within a given city or region? The remainder of this essay explores the research around these questions and considers some possible conclusions.

Body paragraphs

The body paragraphs of an exploratory essay discuss the research process that you used to explore your topic. This section highlights the sources that you found most useful and explains why they are important to the debate.

You might also use the body paragraphs to address how individual resources changed your thinking about your topic. Most exploratory essays will have several body paragraphs.

One source that was especially useful to my research was a 2016 study by Richard J. Lee and Ipek N. Sener that considers the intersections between transportation planning and quality of life . They argue that, while planners have consistently addressed physical health and well-being in transportation plans, they have not necessarily factored in how mental and social health contributes to quality of life. Put differently, transportation planning has traditionally utilized a limited definition of quality of life and this has necessarily impacted data on the relationship between public transit and quality of life. This resource helped me to broaden my conception of quality of life to include all aspects of human health. It also enabled me to better understand the stakeholders involved in transportation decisions.

Your conclusion should return to the research question stated in your introduction. What are some possible solutions to your questions, based on the sources that you highlighted in your essay? While you shouldn't include new information in your conclusion, you can discuss additional questions that arose as you were conducting your research.

In my introduction, I asked whether public transit improves quality of life for all, not simply for users of public transportation. My research demonstrates that there are strong connections between public transportation and quality of life, but that researchers differ as to how quality of life is defined. Many conclude that public transit improves citizens' lives, but it is still not clear how public transit decisions affect non-users, since few studies have focused on this distinct group. As a result, I believe that more research is needed to answer the research questions that I posed above.

Frequently Asked Questions about exploratory essays

You should begin an exploratory essay by introducing the context for your topic, explaining the topic's importance, and outlining your original research question.

Like other types of essays, the exploratory essay has three primary parts:

Although an exploratory essay does not make a specific argument, your research question technically serves as your thesis.

Yes, you can use "I" throughout your paper. An exploratory essay is meant to explore your own research process, so a first-person perspective is appropriate.

You should end your exploratory essay with a succinct conclusion that returns to your research question and considers possible answers. You can also end by highlighting further questions you may have about your research.

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Exploratory Research

Exploratory research, as the name implies, intends merely to explore the research questions and does not intend to offer final and conclusive solutions to existing problems. This type of research is usually conducted to study a problem that has not been clearly defined yet. Conducted in order to determine the nature of the problem, exploratory research is not intended to provide conclusive evidence, but helps us to have a better understanding of the problem.

When conducting exploratory research, the researcher ought to be willing to change his/her direction as a result of revelation of new data and new insights. [1] Accordingly, exploratory studies are often conducted using interpretive research methods and they answer to questions such as what, why and how.

Exploratory research design does not aim to provide the final and conclusive answers to the research questions, but merely explores the research topic with varying levels of depth. It has been noted that “exploratory research is the initial research, which forms the basis of more conclusive research. It can even help in determining the research design, sampling methodology and data collection method” [2] . Exploratory research “tends to tackle new problems on which little or no previous research has been done” [3] .

Unstructured interviews are the most popular primary data collection method with exploratory studies. Additionally, surveys , focus groups and observation methods can be used to collect primary data for this type of studies.

Examples of Exploratory Research Design

The following are some examples for studies with exploratory research design in business studies:

• A study into the role of social networking sites as an effective marketing communication channel
• An investigation into the ways of improvement of quality of customer services within hospitality sector in London
• An assessment of the role of corporate social responsibility on consumer behaviour in pharmaceutical industry in the USA

Differences between Exploratory and Conclusive Research

The difference between exploratory and conclusive research is drawn by Sandhursen (2000) [4] in a way that exploratory studies result in a range of causes and alternative options for a solution of a specific problem, whereas, conclusive studies identify the final information that is the only solution to an existing research problem.

In other words, exploratory research design simply explores the research questions, leaving room for further researches, whereas conclusive research design is aimed to provide final findings for the research.

Moreover, it has been stated that “an exploratory study may not have as rigorous as methodology as it is used in conclusive studies, and sample sizes may be smaller. But it helps to do the exploratory study as methodically as possible, if it is going to be used for major decisions about the way we are going to conduct our next study” [5] (Nargundkar, 2003, p.41).

Exploratory studies usually create scope for future research and the future research may have a conclusive design. For example, ‘a study into the implications of COVID-19 pandemic into the global economy’ is an exploratory research. COVID-19 pandemic is a recent phenomenon and the study can generate an initial knowledge about economic implications of the phenomenon.

A follow-up study, building on the findings of this research ‘a study into the effects of COVID-19 pandemic on tourism revenues in Morocco’ is a causal conclusive research. The second research can produce research findings that can be of a practical use for decision making.

Advantages of Exploratory Research

• Lower costs of conducting the study
• Flexibility and adaptability to change
• Exploratory research is effective in laying the groundwork that will lead to future studies.
• Exploratory studies can potentially save time by determining at the earlier stages the types of research that are worth pursuing

Disadvantages of Exploratory Research

• Inclusive nature of research findings
• Exploratory studies generate qualitative information and interpretation of such type of information is subject to bias
• These types of studies usually make use of a modest number of samples that may not adequately represent the target population. Accordingly, findings of exploratory research cannot be generalized to a wider population.
• Findings of such type of studies are not usually useful in decision making in a practical level.

My e-book,  The Ultimate Guide to Writing a Dissertation in Business Studies: a step by step assistance  contains discussions of theory and application of research designs. The e-book also explains all stages of the  research process  starting from the  selection of the research area  to writing personal reflection. Important elements of dissertations such as  research philosophy ,  research approach ,  methods of data collection ,  data analysis  and  sampling  are explained in this e-book in simple words.

John Dudovskiy

[1] Source: Saunders, M., Lewis, P. & Thornhill, A. (2012) “Research Methods for Business Students” 6 th  edition, Pearson Education Limited

[2] Singh, K. (2007) “Quantitative Social Research Methods” SAGE Publications, p.64

[3] Brown, R.B. (2006) “Doing Your Dissertation in Business and Management: The Reality of Research and Writing” Sage Publications, p.43

[4] Sandhusen, R.L. (2000) “Marketing” Barrons

[5] Nargundkar, R. (2008) “Marketing Research: Text and Cases” 3 rd edition, p.38

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Organizing an Exploratory Essay

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Exploratory essays are very different from argumentative essays. In fact, an exploratory essay is likely different from any other essay you’ve written. Instead of writing to convince an audience of the validity of a thesis, you will be writing to find out about a problem and perhaps to form some preliminary conclusions about how it might be solved.

But there is another aspect the exploratory genre that is equally important. An exploratory essay is, in essence, a retrospective of your writing and thinking process as you work through a problem. It describes when, how, and why you completed certain types of research. This kind of writing is about how you work through problems that require writing and research. You will have to be introspective and think about your thinking process in order for your essay to turn out well.

Very roughly, then, your exploratory essay may follow this sort of structure:

Introduction

The introduction should outline the problem you explored and why it’s important. In addition, you should briefly discuss 1) some of the problem’s possible causes; 2) the institutions and people involved with the problem; 3) some of the possible solutions to the problem. A brief overview of the types of sources you researched during your inquiry.

Body Paragraphs

Body paragraphs should discuss the inquiry process you followed to research your problem. These paragraphs should include the following:

• Introduction of source (title, author, type of media, publisher, publication date, etc.) and why you chose to use it in your exploration
• Important information you found in the source regarding your problem
• Why the information is important and dependable in relation to the problem
• Some personal introspection on how the source helped you, allowed you to think differently about the problem, or even fell short of your expectations and led you in a new direction in your research, which forms a transition into your next source.

The conclusion should restate the problem you explored, outline some of its possible causes, review the institutions and people involved, and highlight some possible solutions. If you still have any questions about the problem (and it’s ok to have some), you will discuss them here. Talk about why you think you still have questions regarding the problem you explored, where you might look to answer these questions, and what other forms of research you would have to do.

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• Pilot Feasibility Stud

Exploratory studies to decide whether and how to proceed with full-scale evaluations of public health interventions: a systematic review of guidance

Britt hallingberg.

1 Centre for the Development and Evaluation of Complex Interventions for Public Health Improvement (DECIPHer), Cardiff University, Cardiff, Wales UK

Ruth Turley

4 Specialist Unit for Review Evidence, Cardiff University, Cardiff, Wales UK

Jeremy Segrott

2 Centre for Trials Research, Cardiff University, Cardiff, Wales UK

Daniel Wight

3 MRC/CSO Social and Public Health Sciences Unit, University of Glasgow, Glasgow, UK

Peter Craig

Laurence moore, simon murphy, michael robling, sharon anne simpson, graham moore, associated data.

The datasets generated and/or analysed during the current study are not publicly available due to copyright infringement.

Evaluations of complex interventions in public health are frequently undermined by problems that can be identified before the effectiveness study stage. Exploratory studies, often termed pilot and feasibility studies, are a key step in assessing the feasibility and value of progressing to an effectiveness study. Such studies can provide vital information to support more robust evaluations, thereby reducing costs and minimising potential harms of the intervention. This systematic review forms the first phase of a wider project to address the need for stand-alone guidance for public health researchers on designing and conducting exploratory studies. The review objectives were to identify and examine existing recommendations concerning when such studies should be undertaken, questions they should answer, suitable methods, criteria for deciding whether to progress to an effectiveness study and appropriate reporting.

We searched for published and unpublished guidance reported between January 2000 and November 2016 via bibliographic databases, websites, citation tracking and expert recommendations. Included papers were thematically synthesized.

The search retrieved 4095 unique records. Thirty papers were included, representing 25 unique sources of guidance/recommendations. Eight themes were identified: pre-requisites for conducting an exploratory study, nomenclature, guidance for intervention assessment, guidance surrounding any future evaluation study design, flexible versus fixed design, progression criteria to a future evaluation study, stakeholder involvement and reporting of exploratory studies. Exploratory studies were described as being concerned with the intervention content, the future evaluation design or both. However, the nomenclature and endorsed methods underpinning these aims were inconsistent across papers. There was little guidance on what should precede or follow an exploratory study and decision-making surrounding this.

Conclusions

Existing recommendations are inconsistent concerning the aims, designs and conduct of exploratory studies, and guidance is lacking on the evidence needed to inform when to proceed to an effectiveness study.

Trial registration

PROSPERO 2016, CRD42016047843

Electronic supplementary material

The online version of this article (10.1186/s40814-018-0290-8) contains supplementary material, which is available to authorized users.

Improving public health and disrupting complex problems such as smoking, obesity and mental health requires complex, often multilevel, interventions. Such interventions are often costly and may cause unanticipated harms and therefore require evaluation using the most robust methods available. However, pressure to identify effective interventions can lead to premature commissioning of large effectiveness studies of poorly developed interventions, wasting finite research resources [ 1 – 3 ]. In the development of pharmaceutical drugs over 80% fail to reach ‘Phase III’ effectiveness trials, even after considerable investment [ 4 ]. With public health interventions, the historical tendency to rush to full evaluation has in some cases led to evaluation failures due to issues which could have been identified at an earlier stage, such as difficulties recruiting sufficient participants [ 5 ]. There is growing consensus that improving the effectiveness of public health interventions relies on attention to their design and feasibility [ 3 , 6 ]. However, what constitutes good practice when deciding when a full evaluation is warranted, what uncertainties should be addressed to inform this decision and how, is unclear. This systematic review aims to synthesize existing sources of guidance for ‘exploratory studies’ which we broadly define as studies intended to generate evidence needed to decide whether and how to proceed with a full-scale effectiveness study. They do this by optimising or assessing the feasibility of the intervention and/or evaluation design that the effectiveness study would use. Hence, our definition includes studies variously referred to throughout the literature as ‘pilot studies’, ‘feasibility studies’ or ‘exploratory trials’. Our definition is consistent with previous work conducted by Eldridge et al. [ 7 , 8 ], who define feasibility as an overarching concept [ 8 ] which assesses; ‘… whether the future trial can be done, should be done, and, if so, how’ (p. 2) [ 7 ]. However, our definition also includes exploratory studies to inform non-randomised evaluations, rather than a sole focus on trials.

The importance of thoroughly establishing the feasibility of intervention and evaluation plans prior to embarking on an expensive, fully powered evaluation was indicated in the Medical Research Council’s (MRC) framework for the development and evaluation of complex interventions to improve health [ 9 , 10 ]. This has triggered shifts in the practice of researchers and funders toward seeking and granting funding for an ever growing number of studies to address feasibility issues. Such studies are however in themselves often expensive [ 11 , 12 ]. While there is a compelling case for such studies, the extent to which this substantial investment in exploratory studies has to date improved the effectiveness and cost-effectiveness of evidence production remains to be firmly established. Where exploratory studies are conducted poorly, this investment may simply lead to expenditure of large amounts of additional public money, and several years’ delay in getting evidence into the hands of decision-makers, without necessarily increasing the likelihood that a future evaluation will provide useful evidence.

The 2000 MRC guidance used the term ‘exploratory trial’ for work conducted prior to a ‘definitive trial’, indicating that it should primarily address issues concerning the optimisation, acceptability and delivery of the intervention [ 13 ]. This included adaptation of the intervention, consideration of variants of the intervention, testing and refinement of delivery method or content, assessment of learning curves and implementation strategies and determining the counterfactual. Other possible purposes of exploratory trials included preliminary assessment of effect size in order to calculate the sample size for the main trial and other trial design parameters, including methods of recruitment, randomisation and follow-up. Updated MRC guidance in 2008 moved away from the sole focus on RCTs (randomised controlled trials) of its predecessor reflecting recognition that not all interventions can be tested using an RCT and that the next most robust methods may sometimes be the best available option [ 10 , 14 ]. Guidance for exploratory studies prior to a full evaluation have, however, often been framed as relevant only where the main evaluation is to be an RCT [ 13 , 15 ].

However, the goals of exploratory studies advocated by research funders have to date varied substantially. For instance, the National Institute for Health Research Evaluation Trials and Studies Coordinating Centre (NETSCC) definitions of feasibility and pilot studies do not include examination of intervention design, delivery or acceptability and do not suggest that modifications to the intervention prior to full-scale evaluation will arise from these phases. However, the NIHR (National Institute of Health Research) portfolio of funded studies indicates various uses of terms such as ‘feasibility trial’, ‘pilot trial’ and ‘exploratory trial’ to describe studies with similar aims, while it is rare for such studies not to include a focus on intervention parameters [ 16 – 18 ]. Within the research literature, there is considerable divergence over what exploratory studies should be called, what they should achieve, what they should entail, whether and how they should determine progression to future studies and how they should be reported [ 7 , 8 , 19 – 21 ].

This paper presents a systematic review of the existing recommendations and guidance on exploratory studies relevant to public health, conducted as the first stage of a project to develop new MRC guidance on exploratory studies. This review aims to produce a synthesis of current guidance/recommendations in relation to the definition, purpose and content of exploratory studies, and what is seen as ‘good’ and ‘bad’ practice as presented by the authors. It will provide an overview of key gaps and areas in which there is inconsistency within and between documents. The rationale for guidance and recommendations are presented, as well as the theoretical perspectives informing them. In particular, we examine how far the existing recommendations answer the following questions:

• When is it appropriate to conduct an exploratory study?
• What questions should such studies address?
• What are the key methodological considerations in answering these questions?
• What criteria should inform a decision on whether to progress to an effectiveness study?
• How should exploratory studies be reported?

This review is reported in accordance with the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) statement [ 22 ] as evidenced in the PRISMA checklist (see Additional file  1 : Table S1). The review protocol is registered on PROSPERO (registration number: CRD42016047843; www.crd.york.ac.uk/prospero ).

Literature search

A comprehensive search (see Additional file  2 : Appendix) was designed and completed during August to November 2016 to identify published and grey literature reported between January 2000 and November 2016 that contained guidance and recommendations on exploratory studies that could have potential relevance to public health. Bibliographic databases were CINAHL, Embase, MEDLINE, MEDLINE-In-process, PsycINFO, Web of Science and PubMed. Supplementary searches included key websites (see Additional file  2 : Appendix) and forward and backward citation tracking of included papers, as well as contacting experts in the field. The first MRC guidance on developing and evaluating complex interventions in health was published in 2000; we therefore excluded guidance published before this year.

Selection of included papers

Search results were exported into reference management software Endnote and clearly irrelevant or duplicate records removed by an information specialist. Eligibility criteria were applied to abstracts and potentially relevant full-text papers by two reviewers working independently in duplicate (BH, JS). Discrepancies were agreed by consensus or by a third reviewer if necessary. Full criteria are shown in Table  1 . During screening of eligible studies, it became evident that determining whether or not guidance was applicable to public health was not always clear. The criteria in Table  1 were agreed by the team after a list of potentially eligible publications were identified.

Eligibility criteria for selecting papers

Quality assessment of included papers

Given the nature of publications included (expert guidance or methodological discussion papers) quality assessment was not applicable.

Data extraction and thematic synthesis

A thematic synthesis of guidance within included documents was performed [ 23 ]. This involved the use of an a priori coding framework (based on the projects aims and objectives), developed by RT, JS and DW ([ 24 ], see Additional file  2 : Appendix). Data were extracted using this schema in qualitative analytic software NVivo by one reviewer (BH). A 10% sample of coded papers was checked by a second reviewer (JS). Data were then conceptualised into final themes by agreement (BH, JS, DW, RT).

Review statistics

Four thousand ninety-five unique records were identified of which 93 were reviewed in full text (see Fig.  1 ). In total, 30 documents were included in the systematic review representing 25 unique sets of guidance. Most sources of guidance did not explicitly identify an intended audience and guidance varied in its relevance to public health. Table  2 presents an overview of all sources of guidance included in the review with sources of guidance more or less relevant to public health identified as well as those which specifically applied to exploratory studies with a randomised design.

Flow diagram

Summary of included guidance

a Guidance with greater relevance to public health included those where public health audiences was clearly among intended users of the guidance (authors are from Public Health departments, cites literature from public health journals, provides public health examples or uses the term ‘public health’ or variants of this, e.g. ‘prevention science’, ‘health improvement’). Guidance with less relevance was not specific about the intended audience but was of plausible relevance to public health (might, for example, include either an author from a public health research department or a citation to a public health journal).

b Authors make distinctions between the terms “pilot study” and “feasibility study”. c Aims of exploratory studies presented in the table map onto aims presented in themes 3 ( Guidance for intervention assessment ) and 4 ( Guidance surrounding the future evaluation design )

Findings from guidance

The included guidance reported a wide range of recommendations on the process of conducting and reporting exploratory studies. We categorised these into eight themes that capture: pre-requisites for conducting an exploratory study, nomenclature, guidance for intervention assessment, guidance surrounding the future evaluation study design, adaptive vs rigid designs, progression criteria for exploratory studies, stakeholder involvement and reporting.

Narrative description of themes

Theme 1: pre-requisites for conducting an exploratory study.

Where mentioned, pre-requisite activities included determining the evidence base, establishing the theoretical basis for the intervention, identifying the intervention components as well as modelling of the intervention in order to understand how intervention components interact and impact on final outcomes [ 9 , 25 – 27 ]. These were often discussed within the context of the MRC’s intervention development-evaluation cycle [ 6 , 9 , 10 , 13 , 25 – 28 ]. Understanding how intervention components interact with various contextual settings [ 6 , 27 , 29 ] and identifying unintended harms [ 6 , 29 ] as well as potential implementation issues [ 6 , 9 , 10 , 30 ] were also highlighted. There was an absence of detail in judging when these above conditions were met sufficiently for moving onto an exploratory study.

Theme 2: nomenclature

A wide range of terms were used, sometimes interchangeably, to describe exploratory studies with the most common being pilot trial/study. Table  3 shows the frequency of the terms used in guidance including other terms endorsed.

Frequency of nomenclature used

Note: terms are not mutually exclusive

Different terminology did not appear to be consistently associated with specific study purposes (see theme 3), as illustrated in Table  2 . ‘Pilot’ and ‘feasibility’ studies were sometimes used interchangeably [ 10 , 20 , 25 – 28 , 31 ] while others made distinctions between the two according to design features or particular aims [ 7 , 8 , 19 , 29 , 32 – 34 ]. For example, some described pilot studies as a smaller version of a future RCT to run in miniature [ 7 , 8 , 19 , 29 , 32 – 34 ] and was sometimes associated with a randomised design [ 32 , 34 ], but not always [ 7 , 8 ]. In contrast, feasibility studies were used as an umbrella term by Eldridge et al. with pilot studies representing a subset of feasibility studies [ 7 , 8 ]: ‘We suggest that researchers view feasibility as an overarching concept, with all studies done in preparation for a main study open to being called feasibility studies, and with pilot studies as a subset of feasibility studies.’ (p. 18) [ 8 ].

Feasibility studies could focus on particular intervention and trial design elements [ 29 , 32 ] which may not include randomisation [ 32 , 34 ]. Internal pilot studies were primarily viewed as part of the full trial [ 8 , 32 , 35 – 38 ] and are therefore not depicted under nomenclature in Table  3 .

While no sources explicitly stated that an exploratory study should focus on one area and not the other, aims and associated methods of exploratory studies diverged into two separate themes. They pertained to either examining the intervention itself or the future evaluation design, and are detailed below in themes 3 and 4.

Theme 3: guidance for intervention assessment

Sources of guidance endorsed exploratory studies having formative purposes (i.e. refining the intervention and addressing uncertainties related to intervention implementation [ 13 , 15 , 29 , 31 , 39 ]) as well as summative goals (i.e. assessing the potential impact of an intervention or its promise [ 6 , 13 , 39 ]).

Refining the intervention and underlying theory

Some guidance suggested that changes could be made within exploratory studies to refine the intervention and underlying theory [ 15 , 29 , 31 ] and adapt intervention content to a new setting [ 39 ]. However, guidance was not clear on what constituted minor vs. major changes and implications for progression criteria (see theme 6). When making changes to the intervention or underlying theory, some guidance recommended this take place during the course of the exploratory study (see theme 5). Others highlighted the role of using a multi-arm design to select the contents of the intervention before a full evaluation [ 13 ] and to assess potential mechanisms of multiple different interventions or intervention components [ 29 ]. Several sources highlighted the role of qualitative research in optimising or refining an intervention, particularly for understanding the components of the logic model [ 29 ] and surfacing hidden aspects of the intervention important for delivering outcomes [ 15 ].

Intervention implementation

There was agreement across a wide range of guidance that exploratory studies could explore key uncertainties related to intervention implementation, such as acceptability, feasibility or practicality. Notably these terms were often ill-defined and used interchangeably. Acceptability was considered in terms of recipients’ reactions [ 7 , 8 , 29 , 32 , 39 ] while others were also attentive to feasibility from the perspective of intervention providers, deliverers and health professionals [ 6 , 9 , 29 , 30 , 34 , 39 ]. Implementation, feasibility, fidelity and ‘practicality’ explored the likelihood of being able to deliver in practice what was intended [ 25 – 27 , 30 , 39 ]. These were sometimes referred to as aims within an embedded process evaluation that took place alongside an exploratory study, although the term process evaluation was never defined [ 7 , 10 , 15 , 29 , 40 ].

Qualitative research was encouraged for assessment of intervention acceptability [ 21 ] or for implementation (e.g. via non-participant observation [ 15 ]). Caution was recommended with regards to focus groups where there is a risk of masking divergent views [ 15 ]. Others recommended quantitative surveys to examine retention rates and reasons for dropout [ 7 , 30 ]. Furthermore, several sources emphasised the importance of testing implementation in a range of contexts [ 15 , 29 , 39 , 41 ]—especially in less socioeconomically advantaged groups, to examine the risk of widening health inequalities [ 29 , 39 ].

One source of guidance considered whether randomisation was required for assessing intervention acceptability, believing this to be unnecessary but also suggesting it could ‘potentially depend on preference among interventions offered in the main trial’ ([ 21 ]; p. 9). Thus, issues of intervention acceptability, particularly within multi-arm trials, may relate to clinical equipoise and acceptability of randomisation procedures among participants [ 30 ].

Appropriateness of assessing intervention impact

Several sources of guidance discussed the need to understand the impact of the intervention, including harms, benefits or unintended consequences [ 6 , 7 , 15 , 29 , 39 ]. Much of the guidance focused on statistical tests of effectiveness with disagreement on the soundness of this aim, although qualitative methods were also recommended [ 15 , 42 ]. Some condemned statistically testing for effectiveness [ 7 , 20 , 29 , 32 , 41 ], as such studies are often underpowered, hence leading to imprecise and potentially misleading estimates of effect sizes [ 7 , 20 ]. Others argued that an estimate of likely effect size could evidence the intervention was working as intended and not having serious unintended harms [ 6 ] and thus be used to calculate the power for the full trial [ 13 ]. Later guidance from the MRC is more ambiguous than earlier guidance, stating that estimates should be interpreted with caution, while simultaneously stating ‘safe’ assumptions of effect sizes as a pre-requisite before continuing to a full evaluation [ 10 ]. NIHR guidance, which distinguished between pilot and feasibility studies, supported the assessment of a primary outcome in pilot studies, although it is unclear whether this is suggesting that a pilot should involve an initial test of changes in the primary outcome, or simply that the primary outcome should be measured in the same way as it would be in a full evaluation. By contrast, for ‘feasibility studies’, it indicated that an aim may include designing an outcome measure to be used in a full evaluation.

Others made the case for identifying evidence of potential effectiveness, including use of interim or surrogate endpoints [ 7 , 41 ], defined as ‘…variables on the causal pathway of what might eventually be the primary outcome in the future definitive RCT, or outcomes at early time points, in order to assess the potential for the intervention to affect likely outcomes in the future definitive RCT…’ [ 7 ] (p. 14).

Randomisation was implied as a design feature of exploratory studies when estimating an effect size estimate of the intervention as it maximised the likelihood that observed differences are due to intervention [ 9 , 39 ], with guidance mostly written from a starting assumption that full evaluation will take the form of an RCT and guidance focused less on exploratory studies for quasi-experimental or other designs. For studies that aim to assess potential effectiveness using a surrogate or interim outcome, using a standard sample size calculation was recommended to ensure adequate power, although it was noted that this aim is rare in exploratory studies [ 7 ].

Theme 4: guidance surrounding the future evaluation design

Sources consistently advocated assessing the feasibility of study procedures or estimating parameters of the future evaluation. Recommendations are detailed below.

Assessing feasibility of the future evaluation design

Assessing feasibility of future evaluation procedures was commonly recommended [ 6 , 7 , 10 , 15 , 30 , 32 – 34 , 37 , 41 ] to avert problems that could undermine the conduct or acceptability of future evaluation [ 6 , 15 , 30 ]. A wide range of procedures were suggested as requiring assessments of feasibility including data collection [ 20 , 30 , 34 , 36 , 41 ], participant retention strategies [ 13 ], randomisation [ 7 , 13 , 20 , 30 , 34 , 36 , 38 , 41 ], recruitment methods [ 13 , 30 , 32 , 34 , 35 , 38 , 41 ], running the full trial protocol [ 20 , 30 , 36 ], the willingness of participants to be randomised [ 30 , 32 ] and issues of contamination [ 30 ]. There was disagreement concerning the appropriateness of assessing blinding in exploratory studies [ 7 , 30 , 34 ], with one source noting double blinding is difficult when participants are assisted in changing their behaviour; although assessing single blinding may be possible [ 30 ].

Qualitative [ 15 , 30 , 34 ], quantitative [ 34 ] and mixed methods [ 7 ] were endorsed for assessing these processes. Reflecting the tendency for guidance of exploratory studies to be limited to studies in preparation for RCTs, discussion of the role of randomisation at the exploratory study stage featured heavily in guidance. Randomisation within an exploratory study was considered necessary for examining feasibility of recruitment, consent to randomisation, retention, contamination or maintenance of blinding in the control and intervention groups, randomisation procedures and whether all the components of a protocol can work together, although randomisation was not deemed necessary to assess outcome burden and participant eligibility [ 21 , 30 , 34 ]. While there was consensus about what issues could be assessed through randomisation, sources disagreed on whether randomisation should always precede a future evaluation study, even if that future study is to be an RCT. Contention seemed to be linked to variation in nomenclature and associated aims. For example, some defined pilot study as a study run in miniature to test how all its components work together, thereby dictating a randomised design [ 32 , 34 ]. Yet for feasibility studies, randomisation was only necessary if it reduced the uncertainties in estimating parameters for the future evaluation [ 32 , 34 ]. Similarly, other guidance highlighted an exploratory study (irrespective of nomenclature) should address the main uncertainties, and thus may not depend on randomisation [ 8 , 15 ].

Estimating parameters of the future evaluation design

A number of sources recommended exploratory studies should inform the parameters of the future evaluation design. Areas for investigation included estimating sample sizes required for the future evaluation (e.g. measuring outcomes [ 32 , 35 ]; power calculations [ 13 ]; derive effect size estimates [ 6 , 7 , 39 ]; estimating target differences [ 35 , 43 ]; deciding what outcomes to measure and how [ 9 , 20 , 30 , 36 ]; assessing quality of measures (e.g. for reliability/ validity/ feasibility/ sensitivity [ 7 , 20 , 30 ]; identification of control group [ 9 , 13 ]; recruitment, consent and retention rates [ 10 , 13 , 20 , 30 , 32 , 34 , 36 ]; and information on the cost of the future evaluation design [ 9 , 30 , 36 ].

While qualitative methods were deemed useful for selecting outcomes and their suitable measures [ 15 ], most guidance concentrated on quantitative methods for estimating future evaluation sample sizes. This was contentious due to the potential to over- or under-estimate sample sizes required in a future evaluation due to the lack of precision of estimates from a small pilot [ 20 , 30 , 41 ]. Estimating sample sizes from effect size estimates in an exploratory study was nevertheless argued by some to be useful if there was scant literature and the exploratory study used the same design and outcome as the future evaluation [ 30 , 39 ]. Cluster RCTs, which are common in public health interventions, were specifically earmarked as unsuitable for estimating parameters for sample size calculations (e.g. intra-cluster correlation coefficients) as well as recruitment and follow-up rates without additional information from other resources, because a large number of clusters and individual participants would be required [ 41 ]. Others referred to ‘rules of thumb’ when determining sample sizes in an exploratory study with numbers varying between 10 and 75 participants per trial arm in individually randomised studies [ 7 , 30 , 36 ]. Several also recommended the need to consider a desired meaningful difference in the health outcomes from a future evaluation and the appropriate sample size needed to detect this, rather than conducting sample size calculations using estimates of likely effect size from pilot data [ 30 , 35 , 38 , 43 ].

A randomised design was deemed unnecessary for estimating costs or selecting outcomes, although was valued for estimating recruitment and retention rates for intervention and control groups [ 21 , 34 ]. Where guidance indicated the estimation of an effect size appropriate to inform the sample size for a future evaluation, a randomised design was deemed necessary [ 9 , 39 ].

Theme 5: flexible vs. fixed design

Sources stated that exploratory studies could employ a rigid or flexible design. With the latter, the design can change during the course of the study, which is useful for making changes to the intervention, as well as the future evaluation design [ 6 , 13 , 15 , 31 ]. Here, qualitative data can be analysed as it is collected, shaping the exploratory study process, for instance sampling of subsequent data collection points [ 15 ], and clarifying implications for intervention effectiveness [ 31 ].

In contrast, fixed exploratory studies were encouraged when primarily investigating the future evaluation parameters and processes [ 13 ]. It may be that the nomenclature used in some guidance (e.g. pilot studies that are described as miniature versions of the evaluation) is suggesting a distinction between more flexible vs. more stringent designs. In some guidance, it was not mentioned whether changes should be made during the course of an exploratory study or afterwards, in order to get the best possible design for the future evaluation [ 6 , 7 , 21 ].

Theme 6: progression criteria to a future evaluation study

Little guidance was provided on what should be considered when formulating progression criteria for continuing onto a future evaluation study. Some focussed on the relevant uncertainties of feasibility [ 32 , 39 ], while others highlight specific items concerning cost-effectiveness [ 10 ], refining causal hypotheses to be tested in a future evaluation [ 29 ] and meeting recruitment targets [ 20 , 34 ]. As discussed in themes 3 and 4, statistically testing for effectiveness and using effect sizes for power calculations was cautioned by some, and so criteria based on effect sizes were not specified [ 38 ].

Greater discussion was devoted to how to weight evidence from an exploratory study that addressed multiple aims and used different methods. Some explicitly stated progression criteria should not be judged as strict thresholds but as guidelines using, for example, a traffic lights system with varying levels of acceptability [ 7 , 41 ]. Others highlighted a realist approach, moving away from binary indicators to focusing on ‘what is feasible and acceptable for whom and under what circumstances’ [ 29 ]. In light of the difficulties surrounding interpretation of effect estimates, several sources recommended qualitative findings from exploratory studies should be more influential than quantitative findings [ 15 , 38 ].

Interestingly, there was ambiguity regarding progression when exploratory findings indicated substantial changes to the intervention or evaluation design. Sources considering this issue suggested that if ‘extensive changes’ or ‘major modifications’ are made to either (note they did not specify what qualified as such), researchers should return to the exploratory [ 21 , 30 ] or intervention development phases [ 15 ].

‘Alternatively, at the feasibility phase, researchers may identify fundamental problems with the intervention or trial conduct and return to the development phase rather than proceed to a full trial.’ (p. 1) [ 15 ].

As described previously, however, the threshold at which changes are determined to be ‘major’ remained ambiguous. While updated MRC guidance [ 10 ] moved to a more iterative model, accepting that movement back between feasibility/piloting and intervention development may sometimes be needed, there was no guidance on under what conditions movement between these two stages should take place.

Theme 7: stakeholder involvement

Several sources recommended a range of stakeholders (e.g. intervention providers, intervention recipients, public representatives as well as practitioners who might use the evidence produced by the full trial) be involved in the planning and running of the exploratory study to ensure exploratory studies reflect the realities of intervention setting [ 15 , 28 , 31 , 32 , 39 , 40 ]. In particular, community-based participatory approaches were recommended [ 15 , 39 ]. While many highlighted the value of stakeholders on Trial Steering Committees and other similar study groups [ 15 , 28 , 40 ], some warned about equipoise between researchers and stakeholders [ 15 , 40 ] and also cautioned against researchers conflating stakeholder involvement with qualitative research [ 15 ].

‘Although patient and public representatives on research teams can provide helpful feedback on the intervention, this does not constitute qualitative research and may not result in sufficiently robust data to inform the appropriate development of the intervention.’ (p. 8) [ 15 ].

Theme 8: reporting of exploratory studies

Detailed recommendations for reporting exploratory studies were recently provided in new Consolidated Standards of Reporting Trials (CONSORT) guidance by Eldridge et al. [ 7 ]. In addition to this, recurrent points were brought up by other sources of guidance. Most notably, it was recommended exploratory studies be published in peer-reviewed journals as this can provide useful information to other researchers on what has been done, what did not work and what might be most appropriate [ 15 , 30 ]. An exploratory study may also result in multiple publications, but should provide reference to other work carried out in the same exploratory study [ 7 , 15 ]. Several sources of guidance also highlight that exploratory studies should be appropriately labelled in the title/abstract to enable easy identification; however, the nomenclature suggested varied depending on guidance [ 7 , 8 , 15 ].

While exploratory studies—carried out to inform decisions about whether and how to proceed with an effectiveness study [ 7 , 8 ]—are increasingly recognised as important in the efficient evaluation of complex public health interventions, our findings suggest that this area remains in need of consistent standards to inform practice. At present, there are multiple definitions of exploratory studies, a lack of consensus on a number of key issues, and a paucity of detailed guidance on how to approach the main uncertainties such studies aim to address prior to proceeding to a full evaluation.

Existing guidance commonly focuses almost exclusively on testing methodological parameters [ 33 ], such as recruitment and retention, although in practice, it is unusual for such studies not to also focus on the feasibility of the intervention itself. Where intervention feasibility is discussed, there is limited guidance on when an intervention is ‘ready’ for an exploratory study and a lack of demarcation between intervention development and pre-evaluation work to understand feasibility. Some guidance recognised that an intervention continues to develop throughout an exploratory study, with distinctions made between ‘optimisation/refinement’ (i.e. minor refinements to the intervention) vs. ‘major changes’. However, the point at which changes become so substantial that movement back toward intervention development rather than forward to a full evaluation remains ambiguous. Consistent with past reviews which adopted a narrower focus on studies with randomised designs [ 21 ] or in preparation for a randomised trial [ 8 , 36 ] and limited searches of guidance in medical journals [ 19 , 36 ], terms to describe exploratory studies were inconsistent, with a distinction sometimes made between pilot and feasibility studies, though with others using these terms interchangeably.

The review identifies a number of key areas of disagreement or limited guidance in regards to the critical aims of exploratory studies and addressing uncertainties which might undermine a future evaluation, and how these aims should be achieved. There was much disagreement for example on whether exploratory studies should include a preliminary assessment of intervention effects to inform decisions on progression to a full evaluation, and the appropriateness of using estimates of effect from underpowered data (from non-representative samples and a study based on a not fully optimised version of the intervention) to power a future evaluation study. Most guidance focused purely on studies in preparation for RCTs; nevertheless, guidance varied on whether randomisation was a necessary feature of the exploratory study, even where a future evaluation study was an RCT. Guidance was often difficult to assess regarding its applicability to public health research, with many sources focusing on literature and practice primarily from clinical research, and limited consideration of the transferability of these problems and proposed solutions to complex social interventions, such as those in public health. Progression criteria were highlighted as important by some as a means of preventing biased post hoc cases for continuation. However, there was a lack of guidance on how to devise progression criteria and processes for assessing whether these had been sufficiently met. Where they had not been met, there was a lack of guidance on how to decide whether the exploratory study had generated sufficient insight about uncertainties that the expense of a further feasibility study would not be justified prior to large-scale evaluation.

Although our review included a broad focus on guidance of exploratory studies from published and grey literature and moved beyond a focus on studies conducted in preparation for an RCT specifically, a number of limitations should be noted. Guidance from other areas of social intervention research where challenges may be similar to those in public health (e.g. education, social work and business) may not have been captured by our search strategy. We found few worked examples of exploratory studies in public health that provided substantial information from learned experience and practice. Hence, the review drew largely on recommendations from funding organisations, or relatively abstract guidance from teams of researchers, with fewer clear examples of how these recommendations are grounded in experience from the conduct of such studies. As such, it should be acknowledged that these documents represent one element within a complex system of research production and may not necessarily fully reflect what is taking place in the conduct of exploratory studies. Finally, treating sources of guidance as independent from each other does not reflect how some recommendations developed over time (see for example [ 7 , 8 , 20 , 36 , 41 ]).

There is inconsistent guidance, and for some key issues a lack of guidance, for exploratory studies of complex public health interventions. As this lack of guidance for researchers in public health continues, the implications and consequences could be far reaching. It is unclear how researchers use existing guidance to shape decision-making in the conduct of exploratory studies, and in doing so, how they adjudicate between various conflicting perspectives. This systematic review has aimed largely to identify areas of agreement and disagreement as a starting point in bringing order to this somewhat chaotic field of work. Following this systematic review, our next step is to conduct an audit of published public health exploratory studies in peer-reviewed journals, to assess current practice and how this reflects the reviewed guidance. As part of a wider study, funded by the MRC/NIHR Methodology Research Programme to develop GUidance for Exploratory STudies of complex public health interventions (GUEST; Moore L, et al. Exploratory studies to inform full scale evaluations of complex public health interventions: the need for guidance, submitted), the review has informed a Delphi survey of researchers, funders and publishers of public health research. In turn, this will contribute to a consensus meeting which aims to reach greater unanimity on the aims of exploratory studies, and how these can most efficiently address uncertainties which may undermine a full-scale evaluation.

Additional files

Table S1. PRISMA checklist. (DOC 62 kb)

Appendix 1. Search strategies and websites. Appendix 2. Coding framework. (DOCX 28 kb)

Acknowledgements

We thank the Specialist Unit for Review Evidence (SURE) at Cardiff University, including Mala Mann, Helen Morgan, Alison Weightman and Lydia Searchfield, for their assistance with developing and conducting the literature search.

This study is supported by funding from the Methodology Research Panel (MR/N015843/1). LM, SS and DW are supported by the UK Medical Research Council (MC_UU_12017/14) and the Chief Scientist Office (SPHSU14). PC is supported by the UK Medical Research Council (MC_UU_12017/15) and the Chief Scientist Office (SPHSU15). The work was also undertaken with the support of The Centre for the Development and Evaluation of Complex Interventions for Public Health Improvement (DECIPHer), a UKCRC Public Health Research Centre of Excellence. Joint funding (MR/KO232331/1) from the British Heart Foundation, Cancer Research UK, Economic and Social Research Council, Medical Research Council, the Welsh Government and the Wellcome Trust, under the auspices of the UK Clinical Research Collaboration, is gratefully acknowledged.

Availability of data and materials

Abbreviations, authors’ contributions.

LM, GM, PC, MR, JS, RT and SS were involved in the development of the study. RT, JS, DW and BH were responsible for the data collection, overseen by LM and GM. Data analysis was undertaken by BH guided by RT, JS, DW and GM. The manuscript was prepared by BH, RT, DW, JS and GM. All authors contributed to the final version of the manuscript. LM is the principal investigator with overall responsibility for the project. GM is Cardiff lead for the project. All authors read and approved the final manuscript.

Ethics approval and consent to participate

Not applicable.

Competing interests

The authors declare that they have no competing interests.

Publisher’s Note

Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Contributor Information

Britt Hallingberg, Phone: +44 (0)29 2087 9164, Email: ku.ca.fc@EBgrebgnillaH .

Ruth Turley, Email: ku.ca.fc@LRyelruT .

Jeremy Segrott, Email: ku.ca.fc@JttorgeS .

Daniel Wight, Email: [email protected] .

Peter Craig, Email: [email protected] .

Laurence Moore, Email: [email protected] .

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• Exploratory Research | Definition, Guide, & Examples

Exploratory Research | Definition, Guide, & Examples

Published on 6 May 2022 by Tegan George . Revised on 20 January 2023.

Exploratory research is a methodology approach that investigates topics and research questions that have not previously been studied in depth.

Exploratory research is often qualitative in nature. However, a study with a large sample conducted in an exploratory manner can be quantitative as well. It is also often referred to as interpretive research or a grounded theory approach due to its flexible and open-ended nature.

Table of contents

When to use exploratory research, exploratory research questions, exploratory research data collection, step-by-step example of exploratory research, exploratory vs explanatory research, advantages and disadvantages of exploratory research, frequently asked questions about exploratory research.

Exploratory research is often used when the issue you’re studying is new or when the data collection process is challenging for some reason.

You can use this type of research if you have a general idea or a specific question that you want to study but there is no preexisting knowledge or paradigm with which to study it.

Prevent plagiarism, run a free check.

Exploratory research questions are designed to help you understand more about a particular topic of interest. They can help you connect ideas to understand the groundwork of your analysis without adding any preconceived notions or assumptions yet.

Here are some examples:

• What effect does using a digital notebook have on the attention span of primary schoolers?
• What factors influence mental health in undergraduates?
• What outcomes are associated with an authoritative parenting style?
• In what ways does the presence of a non-native accent affect intelligibility?
• How can the use of a grocery delivery service reduce food waste in single-person households?

Collecting information on a previously unexplored topic can be challenging. Exploratory research can help you narrow down your topic and formulate a clear hypothesis , as well as giving you the ‘lay of the land’ on your topic.

Data collection using exploratory research is often divided into primary and secondary research methods, with data analysis following the same model.

Primary research

In primary research, your data is collected directly from primary sources : your participants. There is a variety of ways to collect primary data.

Some examples include:

• Survey methodology: Sending a survey out to the student body asking them if they would eat vegan meals
• Focus groups: Compiling groups of 8–10 students and discussing what they think of vegan options for dining hall food
• Interviews: Interviewing students entering and exiting the dining hall, asking if they would eat vegan meals

Secondary research

In secondary research, your data is collected from preexisting primary research, such as experiments or surveys.

Some other examples include:

• Case studies : Health of an all-vegan diet
• Literature reviews : Preexisting research about students’ eating habits and how they have changed over time
• Online polls, surveys, blog posts, or interviews; social media: Have other universities done something similar?

For some subjects, it’s possible to use large- n government data, such as the decennial census or yearly American Community Survey (ACS) open-source data.

How you proceed with your exploratory research design depends on the research method you choose to collect your data. In most cases, you will follow five steps.

We’ll walk you through the steps using the following example.

Therefore, you would like to focus on improving intelligibility instead of reducing the learner’s accent.

Step 1: Identify your problem

The first step in conducting exploratory research is identifying what the problem is and whether this type of research is the right avenue for you to pursue. Remember that exploratory research is most advantageous when you are investigating a previously unexplored problem.

Step 2: Hypothesise a solution

The next step is to come up with a solution to the problem you’re investigating. Formulate a hypothetical statement to guide your research.

Step 3. Design your methodology

Next, conceptualise your data collection and data analysis methods and write them up in a research design.

Step 4: Collect and analyse data

Next, you proceed with collecting and analysing your data so you can determine whether your preliminary results are in line with your hypothesis.

In most types of research, you should formulate your hypotheses a priori and refrain from changing them due to the increased risk of Type I errors and data integrity issues. However, in exploratory research, you are allowed to change your hypothesis based on your findings, since you are exploring a previously unexplained phenomenon that could have many explanations.

Step 5: Avenues for future research

Decide if you would like to continue studying your topic. If so, it is likely that you will need to change to another type of research. As exploratory research is often qualitative in nature, you may need to conduct quantitative research with a larger sample size to achieve more generalisable results.

It can be easy to confuse exploratory research with explanatory research. To understand the relationship, it can help to remember that exploratory research lays the groundwork for later explanatory research.

Exploratory research investigates research questions that have not been studied in depth. The preliminary results often lay the groundwork for future analysis.

Explanatory research questions tend to start with ‘why’ or ‘how’, and the goal is to explain why or how a previously studied phenomenon takes place.

Like any other research design , exploratory research has its trade-offs: it provides a unique set of benefits but also comes with downsides.

• It can be very helpful in narrowing down a challenging or nebulous problem that has not been previously studied.
• It can serve as a great guide for future research, whether your own or another researcher’s. With new and challenging research problems, adding to the body of research in the early stages can be very fulfilling.
• It is very flexible, cost-effective, and open-ended. You are free to proceed however you think is best.

Disadvantages

• It usually lacks conclusive results, and results can be biased or subjective due to a lack of preexisting knowledge on your topic.
• It’s typically not externally valid and generalisable, and it suffers from many of the challenges of qualitative research .
• Since you are not operating within an existing research paradigm, this type of research can be very labour-intensive.

Exploratory research is a methodology approach that explores research questions that have not previously been studied in depth. It is often used when the issue you’re studying is new, or the data collection process is challenging in some way.

You can use exploratory research if you have a general idea or a specific question that you want to study but there is no preexisting knowledge or paradigm with which to study it.

Exploratory research explores the main aspects of a new or barely researched question.

Explanatory research explains the causes and effects of an already widely researched question.

Quantitative research deals with numbers and statistics, while qualitative research deals with words and meanings.

Quantitative methods allow you to test a hypothesis by systematically collecting and analysing data, while qualitative methods allow you to explore ideas and experiences in depth.

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A guide to exploratory research design

Last updated

9 March 2023

Reviewed by

Jean Kaluza

Knowledge is power, especially when designing a new product or improving an existing one. You may have questions like who will use your product. What niche market needs this product? How will customers respond to the product? Where does the product need improving?

Analyze exploratory research

Finds answers to questions asked in your exploratory research faster when you analyze it in Dovetail

• What is exploratory research?

When you're blazing a trail for a new concept, you need questions answered and problems solved. Exploratory research will help you better understand the problems and offer solutions you could focus on to transform the idea into reality.

What is an exploratory research design example?

When you have an idea about a new product, you're excited about the prospect that customers will be lining up at the door to purchase it. Before spending money on design and development, determine if customers will love it as much as you do.

You will want to conduct exploratory research to determine how people will respond to your product. Your data may show that your potential customers have a different opinion than you expected. Once you receive the data, your perception of how to proceed with the product's design will become more apparent.

• Methods and types of exploratory research

Understanding the methods of exploratory research and how to reach potential customers can provide valuable data for product conception. There are two primary methods of conducting exploratory research: primary research and secondary research.

Primary research

Primary research involves direct interactions with your customer base. This could include conducting surveys , hosting focus groups , or one-on-one interviews. 

Primary research aims to gather first-hand information about your customers' needs, preferences, and opinions. You can gain valuable insights into their behaviors and decision-making processes by interacting directly with your target audience.

Secondary research

Secondary research involves gathering information that others have already collected. This could include conducting online searches, reviewing industry reports, or visiting the library to read books and journals. Secondary research aims to gather information that can help you better understand your target market and industry trends.

• Exploratory research data collection

Gathering data about a new subject can be difficult. But exploratory research can make it easier by helping you focus on a specific topic and creating a clear hypothesis and problem statement. It also gives you an overview of the subject.

Exploratory research involves two types of data collection methods: primary and secondary research. Both methods follow the same model for data analysis.

Primary research methods

This research method involves communicating with people in different ways to gather information, including:

Observations

Interviews 

Focus groups

You might have your product's models, drawings, or prototypes ready for testing. Then, you can gather a target sample group to interact with it. By observing their interactions and listening to their questions, answers, and comments, you can identify necessary changes to the product. This process will also give you insights into how customers will respond to it when it launches.

Exploratory research questions

Once you establish which primary research method you will use, tailor those methods to retrieve data that will answer questions about moving forward with your product. 

These questions can include the following:

Who will get the most benefit from using the product?

What features of the product will customers most likely use or not use?

Is the product easy to use or too complicated?

How can the product be improved?

Secondary research methods

This research method is limited in providing a detailed understanding of product performance among potential customers. Nevertheless, it can help you explore whether similar concepts have been tried before and their success rates. To gather such data, you can refer to these sources:

Case studies

Existing literature

Online sources

• Characteristics of exploratory research

When exploring what type of data you require for your project, consider the characteristics of exploratory research. Check whether the following features align with your project's needs.

Difficult to quantify

It’s extremely difficult to quantify unstructured data. This data type does not typically contain common variables to compare corresponding data points to. However, quantitative data points can be pulled if studies are conducted with a large enough sample size. It just takes significantly longer to analyze. Still, unstructured data is more valuable because it's open-ended qualitative feedback that will help direct your project.

Low-cost, interactive, open-ended

Taking the time to budget for exploratory research has excellent cost-saving significance. The cost of designing and developing a product that may not do well on the market can be higher than what you spend when doing exploratory research.

And the research doesn't have to stop after one survey or one focus group. You can continue this type of interactive research with your target group or customer base throughout all phases of product development. This includes the design, manufacturing, market introduction, and customer experience phases.

Time-consuming

Although it is time-consuming to perform exploratory research, this is nothing compared to the time you could waste producing a product that the public might not receive well. Take the time to construct exploratory research designs that will reap high-quality data with steps that include: 

Addressing the problems that you will need to solve

Identifying the target sample group

Designing the data collection format

Collecting the data

Categorizing the data into useful information

Incorporating the information into the design process

Depending on how extensive your target sample group is and what formats you use to collect the data, this also may impact how long it takes to get the information you need. 

For example, a survey format may take less time than an interview structure. And if you're surveying 15,000 people rather than just 1,000, this can take a while to receive and examine the results.

• When to use exploratory research

Exploratory research can be used not only for product design issues but also to determine the ideal market target and improve customer experience with your product or service.

For example, suppose your business has a website or app. In that case, you can use exploratory research to determine user experience when customers use them. 

• How to conduct exploratory research

In conducting exploratory research, here are the steps you can follow:

Step 1: Identify your problem

Regarding product design, the first step is identifying what obstacles, challenges, or motivations your product will solve for your customers to become viable in the market.

Step 2: Hypothesize a solution

Conducting secondary research on products similar to yours can provide valuable insights that can help you develop a successful solution. By examining the launch and performance of these products, you can generate hypotheses about what may work for your own product.

You may want to add features to your product that were considered successful or remove features that weren't.

Step 3: Design your methodology or process

Next, determine at what points and how you want to collect feedback on your product as you design and iterate it. Perhaps, surveys adequately produce the data you need at the conceptual phase, and running a focus group could be better before the alpha release.

The processes and methodology depend on your resources, team strengths, and at which points in the development process you need direction the most.

Step 4: Collect and analyze data

Analyzing the data collected is how we make our findings actionable. Techniques such as content analysis , thematic analysis , or grounded theory help identify patterns and themes in the data.

If we identify a theme where potential customers are consistently choosing our competitor over us, it may indicate a specific feature that they prefer. To address this, we should conduct further exploration and analysis to determine the reason for this preference. Based on our findings, we may need to build and design similar features to better compete with our rivals.

Step 5: Avenues for future research

If the research that you did helps the design process of your product, you now have a proven avenue for future research in product design, manufacturing, market introduction, and customer experiences for your business. 

• Advantages of exploratory research

Exploratory research provides significant cost-effectiveness and time-savings on projects. If a project is unsuccessful because you did not conduct exploratory research, it will lead to much more cost and time expenditures in the future. And once you have a proven exploratory research process established, it will be easier to do further research when needed.

• Challenges of exploratory research

When doing exploratory research, flexibility is key. If you're unwilling to be open to the results, bias can factor into data interpretation, rendering the data useless. Also, if you haphazardly assemble a quick study with a small sample, the sample size may not represent the target audience.

• The extra effort of exploratory research is worth it

Now that you know the significance of exploratory research and its impact on successful product development and customer experience , it's time to initiate your exploratory research design. And to organize your exploratory research efforts, find a platform that helps you store customer research , feedback, and insights all in one place.

What is exploratory research vs. descriptive?

Exploratory research studies unexamined topics or problems. Descriptive research describes the characteristics of a subject to compare and contrast with other subjects observed in the same study.

Which exploratory research is the quickest and least costly?

Secondary research methods are the quickest and less costly. However, they do not offer comprehensive or specified information that will help develop a product design. Primary research methods can be more expensive than secondary ones but still possible to conduct on a budget.

Which type of research design takes the longest?

Primary research takes the longest because of the necessary steps to collect the information you need. It also depends on how wide of a net you cast to collect the data. The more people involved in surveys, focus groups, and interviews, the more time it will take to extract and analyze the data.

What is the sample size of exploratory research?

The sample size is the number of people participating in your exploratory research design. The sample size should be representative of the target audience for your product.

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