Stéphane Corlosquet wrote: > Hi all, > > I'm new to solr so please let me know if there is a more appropriate place > for my question below. > > I'm noticing a rather unexpected number of results when I add more keywords > to a search. I'm listing below a example (where I replaced the real keywords > with placeholders): > > keyword1 851 hits > keyword1 keyword2 90 hits > keyword1 keyword2 keyword3 269 hits > keyword1 keyword2 keyword3 keyword4 47 hits > > As you can see, adding k2 narrows down the amount of results (as I would > expect), but adding k3 to k1 and k2 suddenly increases the amount of > results. with 4 keywords, the results have been narrowed down again.
My guess - you might have it configured it so at least 60% of keywords have to hit. For 1 or 2 keywords, that means they all need to hit. For 3 keywords, that means 2 of the 3 need to match. For 4 keywords, that means 3 of the 4 need to hit. Or you might have a more complicated expression with effectively the same results. It might be this "mm" parameter you're looking for: http://wiki.apache.org/solr/DisMaxQParserPlugin#mm_.28Minimum_.27Should.27_Match.29
