Hi All,
Why do people use Google instead of Wikipedia search? Two obvious answers come to mind: Google gives better results, and users are just used to using Google 'cause it's useful.
So I set out to see how search on Wikipedia compares to Google for queries we can recover from referrals from Google.
Disclaimers: we don't know what personalized results people got, whether they liked the result, or what they intended to search for; all we have is the wiki page they landed on. Also, results vary depending on which Google you start from—which I didn't consider until after the experiments and analysis were underway.
Summary: for about 60% of queries, Wikipedia search does fine. (And about a quarter of all searches are exact matches for Wikipedia article titles.)
Trouble areas identified include: typos in the first two characters, question marks, abbreviations and other ambiguous terms, quotes, questions, formulaic queries, and non-Latin diacritics.
I have a list of about 20 suggestions for projects from small to enormous that we could tackle to improve results (plus another plug for a Relevance Lab!).
Best factoid: someone searched for *what is hummus* and ended up on the wiki page for Hillary Clinton.
Full details here: https://www.mediawiki.org/wiki/User:TJones_(WMF)/Notes/Why_People_Use_Search...
—Trey
Trey Jones Software Engineer, Discovery Wikimedia Foundation