The ESA retrieval model revisited

Among the retrieval models that have been proposed in the last years, the ESA model of Gabrilovich and Markovitch received much attention. The authors report on a significant improvement in the retrieval performance, which is explained with the semantic concepts introduced by the document collection underlying ESA. Their explanation appears plausible but our analysis shows that the connections are more involved and that the "concept hypothesis" does not hold. In our contribution we analyze several properties that in fact affect the retrieval performance. Moreover, we introduce a formalization of ESA, which reveals its close connection to existing retrieval models.