On Sun, Apr 15, 2012 at 11:34 AM, Benson Margulies <bimargul...@gmail.com> wrote: > So, I've been experimenting to learn how the _val_ participates in scores. > > It seems to me that http://wiki.apache.org/solr/FunctionQuery should > explain the *effect* of including an _val_ term in an ordinary query, > starting with a constant.
It's simply added to the score as any other clause in a boolean query would be. > Positive values of _val_ did lead to > positive increments in the score, but clearly not by simple addition. That's just because Lucene "normalizes" scores. By default, this is really just multiplying scores by a magic constant (that by default is the inverse of the sum of squared weights) and doesn't change relative orderings of docs. If you add debugQuery=true and look at the scoring explanations, you'll see that queryNorm component. If you want to go down the rabbit hole on trunk, see IndexSearcher.createNormalizedWeight() -Yonik lucenerevolution.com - Lucene/Solr Open Source Search Conference. Boston May 7-10
