Research Gap Examples: 7 Types of Research Gaps With 21 Example Statements

Most researchers can say what they want to study. Fewer can say what the existing literature has not yet answered. That is the research gap, and examples are the fastest way to learn how to write one.

In short: a research gap is a question the existing studies have not answered well. It usually falls into one of seven types: an evidence gap (studies disagree), a knowledge gap (little research exists), a practical-knowledge gap (practice differs from what research recommends), a methodological gap (the methods used so far are limited), an empirical gap (a claim has not been tested), a theoretical gap (a theory has not been applied or extended) or a population gap (a group has been left out). A strong gap statement names what is known, what is missing and why it matters. To check a topic for gaps, try the research gap finder.

The 7 types of research gap

This classification follows Miles (2017), which is widely used in research-methods teaching.

21 research gap examples

These statements are illustrative. They show the pattern of a good gap statement; check the actual literature in your field before using a similar claim.

Evidence gaps

1. Education: Studies on homework and achievement in primary school report positive, neutral and negative effects, and it is unclear which factors explain the difference.
2. Health: Trials of a nutritional supplement for fatigue disagree on its effect, and differences in dose and duration have not been examined systematically.
3. Economics: Estimates of how minimum wage changes affect youth employment vary widely between regions, with little analysis of why.

Knowledge gaps

1. Environmental science: Microplastic levels have been measured in rivers and oceans, but few studies have measured them in groundwater used for drinking.
2. Computer science: The energy use of training large language models is well studied, but the cumulative energy cost of running them in everyday applications is not.
3. Psychology: Little research has examined how remote work affects the career development of employees who started their first job remotely.

Practical-knowledge gaps

1. Nursing: Guidelines recommend structured handovers between shifts, yet audits show many wards still rely on informal verbal handovers, and the barriers are poorly understood.
2. Software engineering: Secure-coding practices are widely taught, but how development teams apply them under deadline pressure is rarely studied.
3. Public health: Evidence supports hand-hygiene reminders in clinics, but uptake in small rural clinics remains low and unexplained.

Methodological gaps

1. Psychology: Most studies of social media and adolescent wellbeing are cross-sectional and self-reported, so the direction of the effect is unclear.
2. Management: Research on leadership and burnout relies mostly on single-source surveys; few studies combine survey data with objective measures such as absence records.
3. Ecology: Pollinator decline is usually studied in single seasons, and multi-year field studies remain scarce.

Empirical gaps

1. Marketing: Theories suggest that sustainability labels increase willingness to pay, but this has rarely been tested with real purchase data rather than stated preferences.
2. Education: It is often claimed that AI tutors close attainment gaps, but there are few controlled studies in real classrooms.
3. Urban studies: The idea that new metro lines reduce car use is widely assumed, yet few cities have measured it before and after opening.

Theoretical gaps

1. Information systems: The technology acceptance model has been applied widely to students, but not to clinicians adopting AI diagnostic tools, where professional liability may change the decision.
2. Sociology: Theories of social capital have rarely been used to explain participation in online volunteer communities.
3. Linguistics: Second-language acquisition theories have seldom been tested on learners who acquire a language mainly through video and social media.

Population gaps

1. Medicine: Most evidence on a common heart medication comes from men under 65; women and older adults are under-represented.
2. Education: Research on doctoral student wellbeing focuses on full-time students in the US and UK, with little on part-time students in low- and middle-income countries.
3. Agriculture: Studies of climate-adaptation practices focus on large commercial farms, not smallholders.

A template for your own gap statement

Use three parts: what is known, what is missing, and why it matters.

Template: Research has shown [what is known]. However, [what has not been studied, tested, compared or explained] for [population, setting or method]. Addressing this matters because [consequence for theory, practice or policy].

How to test whether your gap is real

A topic can be unstudied because it does not matter. Before you commit, check:

1. Search beyond your first database. Include other languages and recent preprints; your gap may have been filled last year.
2. Ask why the gap exists. Data may be impossible to collect, or the question may be trivial.
3. Look for a unique angle, not just a new setting. Repeating a known study in a new country is a weak gap unless the setting changes the theory or the answer.
4. Try to argue against it. Ask colleagues, or prompt an AI tool to find studies that already answer your question rather than to confirm the gap.

Economist Dr. Craig Palsson covers how to find a unique angle and tell a genuine gap from an unimportant one in his SciSpace session:

Key moments: 18:49 finding a unique angle · 23:35 why finding the literature for a gap is hard · 43:00 telling a genuine gap from an unimportant one. For a researcher-led check, see how to test whether your research gap is real (another SciSpace session).

Watch: find research gaps while you review the literature

This SciSpace webinar shows how to spot gaps as you read and write your literature review, rather than as a separate step at the end.

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