Currently, I don't know what it's being used for1. What should it be used for? Should we burninate it?
1Actually, it looks like its being used both for research claims and when people want to find something out.
Currently I think it is used when the question is about some specific research or study, or it expects some authoritative study references from the answers.
Academia.SE has similar tag and it's described as:
Questions directly focused on performing academic research applicable to any discipline.
This tag is only for questions that are directly about research. Do not use it for questions tangentially related to research.
For example, if you are asking about how to best cite something, you are probably doing so because you are publishing your research. Such a question would only be related to research, but not about it, and should thus not be tagged research. If you are however asking, e.g., how to best organise your research, the question is actually about research and thus should be tagged research.