Impact Transformation: Effective and Efficient Web Retrieval


Vo Ngoc Anh
Department of Computer Science and Software Engineering, The University of Melbourne, Victoria 3010, Australia.

Alistair Moffat
Department of Computer Science and Software Engineering, The University of Melbourne, Victoria 3010, Australia.


Status

Proc. 25th Annual International ACM SIGIR Conference on Research and Development in Information Retrieval, Tampere, Finland, August 2002, pages 3-10.

Abstract

We extend the applicability of impact transformation, which is a technique for adjusting the term weights assigned to documents so as to boost the effectiveness of retrieval when short queries are applied to large document collections. In conjunction with techniques called quantization and thresholding, impact transformation allows improved query execution rates compared to traditional vector-space similarity computations, as the number of arithmetic operations can be reduced. The transformation also facilitates a new dynamic query pruning heuristic. We give results based upon the TREC web data that show the combination of these various techniques to yield highly competitive retrieval, in terms of both effectiveness and efficiency, for both short and long queries.