How do I compare phrases for similarity?

Question

When entering a question, stackoverflow presents you with a list of questions that it thinks likely to cover the same topic. I have seen similar features on other sites or in ot

Answer 1

From my (rather small) experience developing full-text search engines: I would look up questions which contain some words from query (in your case, query is your question). Sure, noise words should be ignored and we might want to check query for 'strong' words like 'ASP.Net' to narrow down search scope. http://en.wikipedia.org/wiki/Index_(search_engine)#Inverted_indices'>Inverted indexes are commonly used to find questions with words we are interested in.

After finding questions with words from query, we might want to calculate distance between words we are interested in in questions, so question with 'phrases similarity' text ranks higher than question with 'discussing similarity, you hear following phrases...' text.