When it comes to Commons, I would be very interested to learn how many readers (or recipients) are actually non Wikipedia editors.

I do outreach including training. From that, I am inclined to agree that readers don’t use categories. People who come to edit training are (unsurprisingly) generally already keen readers of Wikipedia, but categories seem to be something they first learn about in edit training. Indeed, one of my outreach offerings is just a talk about Wikipedia, which includes tips for getting more out of the reader experience, like categories, What Links Here, and lots of thing that are in plain view on the standard desktop interface but people aren't looking there. Also many categories exist in parallel with List-of articles and navboxes, which do more-or-less-but-not-exactly the same thing. It may be that readers are more likely to stumble on the lists or see the navbox entries (particularly if the navbox renders open). But all in all, I still think most readers enter Wikipedia via search engines and then progress further through Wikipedia by link clicking and using the Wikipedia search box as their principal navigation tools. Editors use categories principally to increase their edit count (cynical but it's hard to think otherwise given what I see on my watchlist); there's an awful lot of messing about with categories for what seems to be very little benefit to the reader (especially as readers don't seem to use them). And with a lack of obvious ways to intersect categories (petscan is wonderful but neither readers nor most editor know about it) an leads to the never-ending creation of cross-categorisation like https://en.wikipedia.org/wiki/Category:19th-century_Australian_women_writers which is pretty clearly the intersection of 4 category trees that probably should be independent: nationality, sex, occupation, time frame. Sooner or later it will inevitably be further subcategorised into 1870s British-born-Australian cis-women poets First-Monday-in-the-month Indian-born Far-North-Queensland cis-women-with-male-pseudonym romantic-sonnet-poets :-) Obviously categories do have some uses to editors. If you have a source that provides you with some information about some aspect of a group of topics, it can be useful to work your way through each of the entries in the category updating it accordingly. Machines. Yes, absolutely. I use AWB and doing things across a category (and the recursive closure of a category) is my primary use-case for AWB. My second use-case for AWB I use a template-use (template/infobox use is a de-facto category and indeed is a third thing that often parallels a category but unlike lists and navboxes, this form is invisible to the reader). With Commons, again, I don't think readers go there, most haven't even heard of it. It's mainly editors at work there and I think they do use categories. The category structure seems to grow there more organically. There is not the constant "let's rename this category worldwide" or the same level of cross-categorisation on Commons that I see on en.Wikipedia. I note that while we cannot know who is using categories, we can still get page count stats for the category itself. These tend to be close to 0-per-day for a lot of categories (e.g. Town halls in Queensland). Even a category that one might think has much greater interest get relatively low numbers, e.g. "Presidents of the United States" gets 26-per-day views on average. This compares with 37K daily average for the Donald Trump article, 19K for Barack Obama, and 16K for George Washington. So this definitely suggests that the readers who presumably make up the bulk of the views on the presidential articles are not looking at the obvious category for such folk (although they might be moving between presidential articles using by navboxes, succession boxes, lists or other links). Having said that, the Donald Trump article has *53* categories of which Presidents of the United States is number 39 (they appear to be alphabetically ordered), so it is possible that the reader never found the presidential category which is lost in a sea of categories like "21st century Presbyterians" and "Critics of the European Union". I would really have thought that being in the category Presidents of the USA was a slightly more important to the topic of the article than his apparent conversion to Presbyterianism in the 21st century (given he's not categorised as a 20th century Presbyterian). And, somewhat amazingly, there is no apparent category for "Critics of Donald Trump". I must propose it, along with a fully diffused sub-cat system of Critics of Donald Trump's immigration policies, Critics of Donald Trump's hair, etc. By the time I've add all the relevant articles to those categories, I should have at least another 100K edits to my name! Kerry -----Original Message----- From: Wiki-research-l [mailto:wiki-research-l-bounces@lists.wikimedia.org] On Behalf Of Federico Leva (Nemo) Sent: Friday, 25 May 2018 7:14 AM To: Research into Wikimedia content and communities < wiki-research-l(a)lists.wikimedia.org&gt;gt;; Ziko van Dijk &lt;zvandijk(a)gmail.com&gt; Subject: Re: [Wiki-research-l] Reader use of Wikipedia and Commons categories Ziko van Dijk, 24/05/2018 23:08: It would be useful to consider less common but high value usage, for instance people looking for illustrations for a publication. Such searches could be substitutes for specialised (and expensive) databases, so the value provided by Commons categories may be higher than the mere usage numbers suggest. (It should be measured in hours saved or something like that.) Federico _______________________________________________ Wiki-research-l mailing list Wiki-research-l(a)lists.wikimedia.org https://lists.wikimedia.org/mailman/listinfo/wiki-research-l _______________________________________________ Wiki-research-l mailing list Wiki-research-l(a)lists.wikimedia.org https://lists.wikimedia.org/mailman/listinfo/wiki-research-l