I believe two concepts are getting slightly mixed here: the LinearFloatFunction, which is a Solr FunctionQuery, and the original Lucene scoring methodology. FunctionQueries are not part of vanilla Lucene, so you will not explicitly see them mentioned in the Lucene similarity documents.
The best way to understand how FunctionQueries are applied is to use the Solr explanations (&debugQuery=1, I believe). >From my experience, each Function Query you add is treated as another term in the summation. E.g., if the search query has 2 terms and 1 function query is added, you will see 3 terms summed to yield the score. The function query result is multiplied by queryNorm(q), making the effect a bit hard to predict sometimes. Hope this helps, -Graham > -----Original Message----- > From: escher2k [mailto:[EMAIL PROTECTED] > Sent: Thursday, December 28, 2006 3:20 PM > To: solr-user@lucene.apache.org > Subject: Function boosts... > > > I had a question about the way boosting works - is it a > final boost on the score that is returned ? > For instance, in the LinearFloatFunction > (LinearFloatFunction(ValueSource source, float slope, float > intercept)), is the ValueSource is the "core" score returned > by Lucene that gets boosted. > > From, > http://lucene.apache.org/java/docs/api/org/apache/lucene/searc > h/Similarity.html > score(q,d) = coord(q,d) ・ queryNorm(q) ・ \xAD\xF4 ( tf(t in d) ・ > idf(t)2 ・ t.getBoost() ・ norm(t,d) ) So, is ValueSource > really score(q,d) and hence LinearFloatFunction does, Final > Score = score(q,d) * slope + intercept ? > > Thanks. > -- > View this message in context: > http://www.nabble.com/Function-boosts...-tf2892636.html#a8081654 > Sent from the Solr - User mailing list archive at Nabble.com. > >
