In this paper we deal with two issues. First, we discuss the negative effects of term correlation in query
expansion algorithms, and we propose a novel and simple method (query clauses) to represent expanded queries
which may alleviate some of these negative effects. Second, we discuss a method to optimize local
query-expansion methods using genetic algorithms, and we apply this method to improve stemming.
We evaluate this method with the novel query representation method and show very significant
improvements for the problem of stemming optimization.