Defining, Measuring, and Rewarding Scholarly Impact: Mind the Level of Analysis

Ramani et al discuss the grossly incorrect inferences that result from using journal impact factor (JIF) as a proxy to assess individual researcher and article scholarly impact. This invalid practice occurs because of confusion about the definition and measurement of impact at different levels of analysis. Specifically, JIF is a journal-level measure of impact, computed by aggregating citations of individual articles (i.e., upward effect), and is therefore inappropriate when measuring impact at lower levels of analysis, such as that of individual researchers, or of individual articles published in a particular journal.