Let's say you're building search for your blog. If popularity is say number of page views, than a handful might have a million (they made it to hacker news and slashdot). A few dozen may have hundreds of thousand (they only made it to slashdot). The vast majority might have less than 100 page views.
Taking the log ensures you're boosting less aggressively by popularity. You're letting the unpopular articles still compete. I might also recommend a multiplicative boost in this case. log(popularity) * text relevance Shameless plug, but this is discussed quite a bit in chapter 7 of my book, Relevant Search. Email me directly if you'd like a discount code http://manning.com/turnbull Best Doug On Mon, May 30, 2016 at 9:03 AM Mugeesh Husain <muge...@gmail.com> wrote: > Hi, > could any one explain me why people use log function for boosting like > below > <str name="bf">product(log(sum(popularity,wiegh),100)^20</str> > > what is log function please elaborate it ? > > > > -- > View this message in context: > http://lucene.472066.n3.nabble.com/Boost-bf-function-in-solr-tp4279792.html > Sent from the Solr - User mailing list archive at Nabble.com. >
