How to find a research gap

A research gap is a question that the existing literature has not yet answered well enough. It might be a population nobody has studied, a method nobody has applied to a problem, a contradiction between findings or an explanation that is still missing. You find it by reading the literature carefully, not by guessing, and you justify it by showing what is already known and where that knowledge stops.

Common types of research gap

Type	What is missing	Example
Evidence gap	Studies reach conflicting results	Some studies find an effect, others do not
Knowledge gap	A phenomenon is barely studied	A new technology with little empirical work
Population or context gap	Findings exist, but not for your group or setting	Results from the US, nothing on European universities
Methodological gap	The question has only been studied with one method	Only surveys, no observational or experimental data
Theoretical gap	Results are not yet explained by a theory	Patterns are known, mechanisms are not
Practical gap	Research has not been translated into practice	Guidelines exist, but no evaluation of their use

For a thesis, the population, context and methodological gaps are often the most realistic, because they build on established work.

Where to look

1. Limitations and “future research” sections of recent journal articles. Authors often name exactly what is still missing.
2. Review articles and meta-analyses that summarise a field and explicitly point to open questions.
3. Conflicting findings that you notice while building your literature review.
4. Discussion sections where results are explained with “may” or “possibly”, a sign that the mechanism is untested.
5. Conference programmes and recent preprints, which show what people are working on now.
6. Practice: problems you see in a placement, a lab or a dataset that the literature does not address.

A step-by-step method

1. Do a structured literature search on your broad topic and save the results in a reference manager.
2. Read the most recent reviews first to understand the current state.
3. Build a simple matrix: studies as rows, columns for context, population, method and main finding. Empty cells and contradictions are your first candidates.
4. Collect every “further research is needed” statement with its source.
5. Formulate two or three candidate gaps in one sentence each.
6. Run a targeted search for each candidate to check whether someone has already closed it.
7. Choose the candidate that is relevant, feasible and interesting to you, and discuss it with your supervisor.

Testing your gap

Before you commit, run your candidate through these questions:

• Real: a targeted search with several term variants found no study that answers this exact question.
• Relevant: filling it would matter to researchers or practitioners in your field, and you can say why.
• Feasible: you can get the data, participants or material within your timeframe.
• Within your skills: you can use, or learn in time, the method needed.
• Ethically possible: the study can be approved where approval is required.
• Specific: it is narrow enough to be answered in one thesis or paper.

Note: “No one has studied this” is a strong claim. Phrase it carefully, for example “to our knowledge, no study has examined …”, and document the search behind it.

Writing the gap statement

A clear gap statement usually has three parts: what is known, what is not known, and why that matters. For example: “Studies on remote teaching report mixed effects on student engagement. Most of them survey students in general degree programmes, and few examine first-year engineering courses, where teaching relies heavily on lab work. Understanding this context matters because …”

This paragraph usually sits at the end of the literature review or in the introduction. It then leads straight into your research question and, if you need approval or funding, into the rationale of your research proposal.

Mistakes that weaken a gap

• Claiming a gap after reading only a handful of papers.
• Choosing a gap so large that no single project could fill it.
• Confusing “not studied in my city” with a meaningful gap, without explaining why the context changes things.
• Ignoring recent work published after you started reading.
• Picking a gap because it is easy, not because the answer matters.

More guides on getting from topic to question are in the literature section.