Our team is evaluating knowledge bases and one of the featires we want is to be able to track searches to identify trending issues users are searching for. Does OpenKM log searches?
Can be easily implemented, but the question is, log only the query ( it's easy ) or also log the results ( I do not suggest it ).
For what I understand, your objective should be to evaluate if user found or not for what was looking for, I think you need some additional step. Take only as a suggestion. Save all daily search queries done by each user, send a daily mail to the user with all queries to give their feedback ( query useful, not useful, or some way to indicate I've not been able to find information about something with this query ). Obviouly take it only as an aproximation without thinking a lot with the problem, but I think only analize the search history only covers one segment of the problem.