Stop searching, and you will find it: Search-Resistant Concepts in Systematic Searching
Not only might you have heard of this statement, but you have also experienced it. When something is lost, and you concentrate on finding it, it hides away, and you cannot find it. It is not found until you stop searching for it, and it will appear in front of you. Is it another Murphy’s law? I don’t know. What I know is that we practically use this idea in systematic searching. I call them Search-Resistant Concepts.
Search-Resistant Concepts (SRCs) are the concepts that when added to a the search, are more likely to miss the relevant records. In other words, they will bias search towards specificity and reduce the sensitivity in an uncertain way. The best examples are Clinical Outcomes. The three main reasons for existence of such concepts are poor reporting (Visibility and Searchability), lack of standards terminology (Indexability), and our lack of knowledge (Ignorance: Known Unknowns).