“Did you mean?” feature in Lucene.net

Question

Can someone please let me know how do I implement \"Did you mean\" feature in Lucene.net?

Thanks!

Answer 1

Google's "Did you mean?" is (probably; they're secretive, of course) implemented by consulting their query log. Look to see if people who searched for the query you're processing searched for something very similar soon after; if so, it indicates they made a mistake, and realized what they ought to be searching for.

Since you probably don't have a huge query log, you could approximate it. Take the query, split up the terms, see if there are any similar terms in the database (by edit distance, whatever); replace your terms with those nearby terms, and rerun the query. If you get more hits, that was probably a better query. Suggest it to the user. (And since you've already got the hits, and most people only look at the top 2 results, show them those.)