I had the opportunity to response to this question, as follows:
A. The best approach to identify where a gap in the literature exists is to first demonstrate knowledge of what does exist. This, then, is the essence and value of the literature review pertaining to development of the problem statement and purpose with respect to gap identification and justification that the proposed study has not already been conducted. As always, the focus should be on recent, scholarly, and peer-reviewed sources. Use of the online library databases, journal websites, and occasionally, search engines such as scholar.google.com are excellent places to start.
Best doctoral success!
Lawrence (Lonny) R. Ness, PhD, DBA
Founder and President, Dissertation101 Mentoring Services, LLC
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