Next: Introduction
Some Simple Effective Approximations
to the 2--Poisson Model
for Probabilistic Weighted Retrieval
S.E. Robertson -
S. Walker
Centre for Interactive Systems
Research, Department of Information Science, City University
Northampton Square, London EC1V 0HB, UK
Abstract:
The 2--Poisson model for term frequencies is used to suggest ways
of incorporating certain variables in probabilistic models for information
retrieval. The variables concerned are within-document term frequency,
document length, and within-query term frequency. Simple weighting
functions are developed, and tested on the TREC test collection.
Considerable performance improvements (over simple inverse collection
frequency weighting) are demonstrated.
Steve Robertson
Mon May 13 18:33:21 BST 1996