But... the results for "lose weight" and "how to lose weight" are not the same. Nor are the results for "earthquake" vs "what is an earthquake". In both cases if I'm after the latter then it is the more verbose query that yields the better results.
stop words/phrase removal can't be done in a too simplistic manner. words like <how to> signify a different kind of intent. Also if stop words are always removed, queries like <who's who in america> wouldn't work properly.
