What is Research gap?

This framework for identifying research gaps from systematic reviews can direct research agendas to influence future public health policy and practice. Although primarily developed for clinical settings, this framework could be used to identify research gaps from systematic reviews on public health interventions and develop research agendas to address these gaps.  

Research gap means missing elements of related literature and findings.

Research gap is a gap where the question is not properly answered regarding the research done on a topic or the answer is incomplete or not upto the research done.