To my understanding this stems from V(q) ยท V(d) (see the "*Conceptual Scoring Formula*") - the elements in those vectors are *Tf-idf* values, and so, implementation wise (see the "*Practical Scoring Function*"), idf(t) is multiplied by itself: once for the query and once for the document.
HTH, Doron On Wed, Oct 5, 2011 at 10:19 PM, David Ryan <help...@gmail.com> wrote: > Hi, > > The defaulting scoring in Lucene uses tf x idf^2 instead of tf x idf . > Does any have have insight that why not using tf x idf? > > > Here is the note on score calculation. > > https://lucene.apache.org/java/3_4_0/api/core/org/apache/lucene/search/Similarity.html >
