Provide effective means for likely users to be able to find the information they are likely to be interested in. To relate to the rest of the world, pages need to be searchable by major search engines, as well as any search facility that is created specifically to cover knowledge commons.

Knowledge in the commons needs to be findable. To the extent that commoners fail to find the information they are looking for, the knowledge commons has failed in its primary purpose.

Google and many other services start from strings, and use various other techniques to make the search better. Internal text string search is common, so presumably has no great challenges; but what about AI-enhanced internal search; and much more challenging, cross-wiki search?

Semantic search such as SPARQL is an obvious path to explore. But how can this work cross-server? Would we need some kind of specialised server keeping an always-updated record of the complete page graph across the current knowledge commons? (and could that effectively define the extent and boundaries of this commons?)

The challenges seem to be adding AI to local search, and doing any kind of search across a distributed knowledge commons. Of course, the semantic and interlinked nature of this work will make browsing search far more effective, and therefore will provide an alternative to a lot of the AI functionality, which should be more effective in some contexts (but not in others)