How to recognize a real gap
Gaps come in a few recognizable shapes. Knowing them tells you where to look.
Kinds of gap
Most gap statements fall into one of five types. Naming yours makes the statement sharper and the search for counter-examples easier.
| Type | What's missing | Example |
|---|---|---|
| Evidence | Findings conflict or are too thin to conclude | Trials disagree on whether an intervention works |
| Population | A group hasn't been studied | Tested on students, never on older workers |
| Context | A setting or region hasn't been studied | Known in hospitals, unknown in home care |
| Method | Only one approach has been used | All surveys; no longitudinal or qualitative work |
| Theory | Findings lack an explanation | An effect is well documented and nobody knows why |
Where to look in a paper
Limitations and future-work paragraphs are the obvious places. Also check the sample description (who was left out?), the measures (what was the outcome standing in for?), and the date the data were collected.
Recent systematic reviews often list research priorities outright. If one exists for your topic, start there.
Three tests before you commit
First, the "so what" test: who would act differently if the gap were filled? Second, feasibility: can you get the data, the participants or the equipment? Third, the search test: have you looked for the missing study under at least three different sets of keywords?
A gap that passes all three is worth taking to your supervisor.
Writing it down
A workable template: "Research on X has established A and B [citations]. However, these studies have focused on P, and it remains unclear whether the same holds for Q [citations showing where the evidence stops]. This matters because R." Your research question follows in the next sentence.