There are confusing opinions about the phrases; "research gap" or "knowledge gap" which are commonly used in the academic literature. How can we claim a gap, suppose related to a particular construct, or topic, when thousands of articles are published on it? Is what we claim a gap an actual gap or it is a constructed gap?
Is context (replication) a gap?
What is a theoretical gap/contribution?
What is a methodological gap?
What strategies may be adopted for searching and claiming gap in the research literature?