Fig. 2: Fragmentation of the psychological literature.
The literature does not converge on standards over time, but rather remains fairly consistently fragmented. This trend is observed across novel constructs (green line), measures (orange line), and original measures lumped with their revisions and translations (purple line). Normalised Shannon entropy is a measure of heterogeneity, or fragmentation10. It takes varying numbers of publications per year into account and in our case has an intuitive meaning: closer to 0%, a few measures dominate, closer to 100%, measures are used an equal number of times across publications. Further details in the SI.
