Hi Jian, Are you sure of that? This would be quite a bad thing to do. I am refering to the paper by Robertson at al
http://citeseer.ist.psu.edu/robertson04simple.html in which it is shown that summing up of multiple scores violates a number of basic assumptions in TF/IDF. Although it is shown on the BM25 algorithm it is generalisable to a scoring function like the one used in Lucene. Karl > --- Ursprüngliche Nachricht --- > Von: jian chen <[EMAIL PROTECTED]> > An: java-user@lucene.apache.org > Betreff: Re: About searching in multiple fields with one query > Datum: Sun, 13 Nov 2005 15:29:53 -0800 > > Hi, Karl, > > Looking at the Lucene 1.2 source code, looks to me that the > MultiFieldQueryParser generates a BooleanQuery. Each sub-query with the > BooleanQuery is for one field. The actually calculation of the scoring is > with BooleanScorer.java, where the scores from each sub-query is > accumulated. > > So, without going into more details of the BooleanScorer.java, it seems to > me that the Lucene 1.2 creates a score from each field that is involved, > and > then, calculate a combined score (simple summation of the scores from each > field). > > I like the simplicity with Lucene 1.2, and am considering porting the > compound file format back to Lucene 1.2 so it will be more robust. > > Cheers, > > Jian > > On 11/13/05, Karl Koch <[EMAIL PROTECTED]> wrote: > > > > Hello all, > > > > I have a question about searching within multiple fields. I have the > > following code for doing that (searchFields provides two fields in which > I > > want to search): > > > > IndexSearcher searcher = new IndexSearcher(indexDirectory); > > // search over multiple index fields > > Query query = MultiFieldQueryParser.parse(queryString, searchFields, > > analyser); > > hits = searcher.search(query); > > > > I am wondering how this is done internally (I am using Lucene 1.2). Does > > Lucene 1.2 merge the terms of the two fields and create a single score > > from > > this? Or does Lucene 1.2 create a score from each field that is involved > > and > > then calculate a combined score from all those? > > > > Karl > > > > -- > > Telefonieren Sie schon oder sparen Sie noch? > > NEU: GMX Phone_Flat http://www.gmx.net/de/go/telefonie > > > > --------------------------------------------------------------------- > > To unsubscribe, e-mail: [EMAIL PROTECTED] > > For additional commands, e-mail: [EMAIL PROTECTED] > > > > > -- Telefonieren Sie schon oder sparen Sie noch? NEU: GMX Phone_Flat http://www.gmx.net/de/go/telefonie --------------------------------------------------------------------- To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
