A research gap is an area where existing knowledge is incomplete, limited or unexplored. For Masters and PhD research, you can identify gaps by examining systematic and scoping reviews, comparing existing studies and asking Micro, Meso and Macro questions about what has and has not been researched.

What is a research gap?

Research gaps are not simply holes in the available research. There are typically more gaps than research in general.

Think of research availability as a gradient. Some areas have been researched extensively, while others have not yet been researched. Between them is the research frontier: the boundary between what has been researched and what has not.

This boundary is not a clear, straight line. Research can fill knowledge gradually while leaving smaller gaps within existing evidence. Closer to the research frontier, gaps can become larger and involve innovative theories, technologies or skills that have received less research.

Beyond the research frontier are completely unexplored areas that sit outside current knowledge. Examples from the past include virtual reality and AI in particular applications.

Researchers develop knowledge by building on previous research and filling gaps. These gaps can therefore exist within current knowledge, at the boundary of existing research, or beyond what is currently understood.

Where can you find a research gap?

For Masters and PhD research, the focus should generally be on gaps between current research and gaps at the research boundary. Identifying gaps between existing studies can be difficult because you need detailed knowledge of the research and a systematic approach to reading the literature.

Gaps at the research boundary can be easier to identify because there is more space for new research.

A useful starting point is systematic reviews. Their future research recommendations can point towards areas where further research is needed. Scoping reviews can also be useful because they provide a broader understanding of a research field and can help identify its boundaries.

You can also look at future research recommendations in empirical articles, but starting with reviews can provide a broader picture. An individual empirical paper may identify a gap immediately adjacent to its own research, whereas a review considers a wider body of literature.

Data extraction or data charting tables in systematic and scoping reviews can also help. They summarise characteristics and findings across studies, making it easier to compare what has already been researched and identify what is missing.

How can Micro, Meso and Macro questions help identify research gaps?

Identifying a gap requires you to pay attention to what is not being mentioned or stated in the research. Micro, Meso and Macro questions provide a way to examine this at different levels.

Micro questions focus on the details of existing research, including populations, samples, research methodologies and analysis methods. For example, if research has quantitatively explored learning outcomes from a simulation curriculum for teaching suturing skills, there may be a gap for qualitative research exploring students' experiences and difficulties.

Meso questions step back and examine broader conceptual ideas, including theories, assumptions and approaches to research. If simulation research focuses heavily on Kolb's experiential learning theory, you could consider whether another theory, such as Jeffries' NLN theory, could provide a different perspective.

Macro questions look more broadly at innovation and changes outside academic research. These can include social, sociocultural, political, geopolitical and technological developments. For example, changes such as Saudi Arabia's Vision 2030 may create new areas for research into innovative curriculum approaches and health prevention.

You can download the Micro Meso Macro questions template to support your identification of research gaps.

Do all research gaps need to be researched?

No. Identifying a research gap is only the beginning of considering your research rationale.

There are more gaps than research, and gaps are effectively unlimited because there is still an enormous amount of knowledge that has not been explored. However, the existence of a gap does not automatically mean there is a need for research.

A gap might be too small to explore meaningfully in a study. Existing research may already be sufficiently generalisable to cover it. Alternatively, there may simply be little value in researching that particular gap.

This is why identifying a gap is different from establishing a research rationale. Once you have identified a potential gap, you need to consider whether addressing it is worthwhile and whether there is a genuine need for the proposed research.

How should you use a research gap in your research rationale?

A research gap can provide the starting point for your research rationale, but you still need to establish why the research should be conducted.

Your preliminary research should help you understand what has already been investigated, where knowledge is incomplete and what possibilities exist at the research frontier. Micro, Meso and Macro questions can then help you explore the gap from different perspectives.

The aim is not simply to find something that nobody has researched. You need to determine whether the gap represents a meaningful opportunity for research and whether your proposed study can contribute useful knowledge.

A research gap therefore gives you something to investigate. Your research rationale needs to explain why that gap matters.