An undergrad sent me a message thanking me for my post A Start-to-Finish Literature Review Workflow and asked the question:
Is there an exhaustive way of making sure that the literature gap you have identified is genuinely a gap?
The short answer is, no. There isn’t. But there are ways to get close.
In my experience, the best way to begin is with a specific research topic in mind, but before you have fully developed a question. You get familiar with the literature using the tips from step 4 in my workflow: Identify potential literature.
After you look at the abstracts for these and eliminate the ones that are outside the scope of your topic, pay close attention when you’re doing your Abstract-Introduction-Conclusion extraction reading to suggestions for future research. In my experience, this is the most fruitful way to find gaps. Both my Master’s paper and dissertation research questions were suggested in the future research section of other scholars’ work.
As H. L. Goodall says in Writing the New Ethnography,
To locate a gap in any scholarly literature requires that you read a lot. (emphasis original)
Goodall offers some more specific advice as well:
I don’t think I can give better advice than that. I’ll close out with more from Goodall:
You are reading for the storyline. You may not be sure what you are using it for, at least not yet. But that is all right. Be patient. Ideas, and uses for them, often take time.
You are also reading to find out what is collectively written about an idea, what individual voices have to say about that collective idea, and for an opening that you can address.
There’s no shortcut, I’m afraid. You have to jump into the literature before you know what the gap is. When everything you’ve read is referencing everything else, it’s safe to trust you’ve got a good sense of the topic and know where the gaps are.