SIGIR'98 papers: The impact of query structure and query expansion on retrieval performance

The impact of query structure and query expansion on retrieval performance


Jaana Kekäläinen
Department of Information Studies, The University of Tampere, Finland.

Kalervo Järvelin
Department of Information Studies, The University of Tampere, Finland.


Abstract

The effects of query structures and query expansion (QE) on retrieval performance were tested with a best match retrieval system (INQUERY). Query structure means the use of operators to express the relations between search keys. Eight different structures were tested, representing weak structures (averages and weighted averages of the weights of the keys) and strong structures (e.g., queries with more elaborated search key relations). QE was based on concepts, which were first selected from a conceptual model, and then expanded by semantic relationships given in the model. The expansion levels were (a) no expansion, (b) a synonym expansion, (c) a narrower concept expansion, (d) an associative concept expansion, and (e) a cumulative expansion of all other expansions. With weak structures and Boolean structured queries, QE was not very effective. The best performance was achieved with one of the strong structures at the largest expansion level.


SIGIR'98
24-28 August 1998
Melbourne, Australia.
sigir98@cs.mu.oz.au.