You need enough to specify constructs, measures, inclusion criteria and likely confounders. You do not need a finished monograph before fieldwork. Freeze a protocol, then keep a living related-work file.
Example Question Literature Review
Life Sciences
Data Collection
What counts as enough literature before collecting data?
Example of the kind of research problem you can ask on PhDSOS.
I am anxious I will collect the wrong data because I have not read enough.
Answers
Help this researcher move forward
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