I also have a case (yellow-page) where IDF comes in and destroys the rank. A company listing with a word which occurs in few other listings is not necessarily better than others just because of that. When it gets to the extreme value of IDF=1, we get an artificially high IDF boost.
It is not killed by omitNorms, neither by omitTermFrequencyAndPositions. Any per-field way to get rid of the IDF effect? Or should I override idf() in Similarity? -- Jan Høydahl, search solution architect Cominvent AS - www.cominvent.com On 15. des. 2010, at 13.27, Robert Muir wrote: > On Wed, Dec 15, 2010 at 3:09 AM, Jan Høydahl / Cominvent > <jan....@cominvent.com> wrote: >> Any way to disable TF/IDF normalization without also disabling positions? >> > > see Similarity.tf(float) and Similarity.tf(int) > > if you want to change this for both terms and phrases just override > Similarity.tf(float), since by default Similarity.tf(int) delegates to > that. > otherwise, override both. > > of course the big limitation being you cant customize Similarity per-field > yet.
