Impact transformation: Effective and efficient web retrieval

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 te..