Fig. 4: Factor analysis of the assessment criteria for promotion to professorship.

The heat map shows the factor loadings (a measure of correlation; Methods) of each assessment criterion in the 532 policies on each of the 4 latent factors (factors 1–4) predicted after principal factor analysis and rotated with the oblimin oblique method. ‘Uniqueness’ is the fraction of the variance that a given criterion does not share with others. Blanks denote loading <0.3 in absolute value, and other values are highlighted with a colour scale; all loadings are shown in Supplementary Table 5. We assigned factor interpretation labels to the four factors, to describe the set of criteria they cover.