Your research question must drive data selection. To define a proper research question and hypothesis, you need to:
Immerse yourself in background reading, review other researchers' work related to your potential topic and critically review their methods to consider what questions/gaps not addressed and how your research can help on these.
To find other researchers' work on a potential topic, I will recommend to do advanced search in linguistics databases such as the database Linguistics & Language Behavior Abstracts . Here is a search example, supposing we are looking for the qualitative researches about Japanese women's language use in working space:
In the example above, each line represents one concept to include in the search. For each concept, several terms could be used by scholars, for example, to describe the concept of qualitative research, "qualitative", "data", "experiment" or one specific tool such as "NVivo" or "survey" could be used. The Boolean (logic) operator "OR" is used to ensure that articles including any of these terms will be retrieved. We could also limit these keywords in a specific field such as "Abstract" or "Document Title" so that the results are more relevant since they should have these terms in the titles or abstracts.
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