My impression is that volunteers on Commons and ENWP spend a lot of time on
categorization. I have seen references to analyses of how categorization is done, but I
can't recall seeing an analysis of how much use readers make of categories on Commons
and ENWP. My guess is that readers often use categories on Commons for media searches, but
that ENWP categories are rarely used by readers, although maybe WMF Discovery uses
categories to inform search results. Is there data that shows how extensively readers on
ENWP and Commons use categories?