Ah I see. Thanks very much Jay for your explanation, it really helped a lot.
I guess I have to deal with this in some other way, since I am working with short titles and I really want short titles to appear at top. Can you suggest anything to bring titles with length 3 to appear before titles with length 4 (given they have similar scores)? Thanks, Jay Hill wrote: > > The fieldNorm is computed like this: fieldNorm = lengthNorm * > documentBoost > * documentFieldBoosts > > and the lengthNorm is: lengthNorm = 1/(numTermsInField)**.5 > [note that the value is encoded as a single byte, so there is some > precision > loss] > > So the values are not pre-set for the lengthNorm, but for some counts the > fieldLength value winds up being the same because of the precision los. > Here > is a list of lengthNorm values for 1 to 10 term fields: > > # of terms lengthNorm > 1 1.0 > 2 .625 > 3 .5 > 4 .5 > 5 .4375 > 6 .375 > 7 .375 > 8 .3125 > 9 .3125 > 10 .3125 > > That's why, in your example, the lengthNorm for 3 and 4 is the same. > > -Jay > http://www.lucidimagination.com > > > > > > On Thu, Mar 11, 2010 at 9:50 AM, muneeb <muneeba...@hotmail.com> wrote: > >> >> >> : >> : Did you reindex after setting omitNorms to false? I'm not sure whether >> or >> : not it is needed, but it makes sense. >> >> Yes i deleted the old index and reindexed it. >> Just to add another fact, that the titlles length is less than 10. I am >> not >> sure if solr has pre-set values for length normalizations, because for >> titles with 3 as well as 4 terms the fieldNorm is coming up as 0.5 (in >> the >> debugQuery section). >> >> >> -- >> View this message in context: >> http://old.nabble.com/field-length-normalization-tp27862618p27867025.html >> Sent from the Solr - User mailing list archive at Nabble.com. >> >> > > -- View this message in context: http://old.nabble.com/field-length-normalization-tp27862618p27874123.html Sent from the Solr - User mailing list archive at Nabble.com.
