En komparativ studie av fem rankningsalgoritmer för query expansion
The purpose of this thesis is to compare five different ranking algorithms for query expansion. The algorithms compared are f4, f4mod, porter, wpq, and emim. This is done using a TREC collection, a selection of topics, and relevance judgements. Relative recall is measured before and after the expansion of the query. The study shows that all of the algorithms manage to increase the relative recall, f4 being the one most successful.