This card tracks a project that's in the Community Wishlist Survey top 10: https://meta.wikimedia.org/wiki/2015_Community_Wishlist_Survey
Original proposal: Categories in Wikimedia Commons must be only in english, but Commons is a multilingual project and it should allow other languages. This change would benefit Commons users that doesn't know english or with a poor level, I know many users of wikipedias that have a lot of problems with that, and that problem makes that many users don't use Commons. I think that the problem exists in a lot of wikipedias. Bye, --Elisardojm (talk) 11:32, 10 November 2015 (UTC)
Community Tech preliminary assessment:
Support: Very high. Unanimous support votes for the concept; comments were about different ways to implement the idea.
Impact: High with structured data, Medium to Low for a straight translation. Searching and sorting images on Commons is already difficult and confusing in English. If we really want to make Commons work well across languages, then we may need to do more than take the confusing English categories and make them confusing multi-lingual categories. Incorporating structured data would be a more scaleable long-term solution.
Feasibility: Difficult. There are hundreds of thousands of categories, maybe more than a million. Starting with A in Special:Categories, the #20,000th category on the list is Abraham. There are also a lot of overlapping categories, ex: Camels, Camelus, Camelus dromedarius, Camel anatomy, Camels eating, Drinking camels, Camel markets, Camel milk, Camels in art, etc. Is it possible for humans to realistically make a dent in translating all these categories in every language? If the solution is creating duplicate categories in each language, it's daunting to think about how to manage up to 200x the current number of categories. That being said, using structured data concepts is also difficult.
Risk: High. This needs scoping and consensus on how this could work, with the Commons community as well as Wikidata.
Status: This is an important problem, and we want to help figure out the best solution. Right now, the most promising line of thought seems to be the "concept tagging" that Wikidata could provide through a structured data platform. The idea is: tag images using concepts that exist in Wikidata, and then cross-reference concepts to find the images you're looking for. Made-up example: instead of having separate categories for Camels, Camel milk and Camel markets, you might be able to mark the images with the concepts "Camels", "Milk" and "Markets". Then you can search for images that have both Camels and Markets, and then drill down into concepts like specific locations. If the concepts are pulled from Wikidata, then they're already translated or translateable. We don't know for sure if that's going to be the ideal solution for this project, but we want to learn more when Wikidata has a working prototype. We'll have more to say as we learn more.