Automatic Query expansion is a well-known method to improve the performance of
information retrieval systems. In this paper, we consider methods to extract the candidate
terms for automatic query expansion, based on co-occurrence information from psuedo
relevant documents. The objective of the paper is: to present to user different ways of
selecting and ranking co-occurring terms and to suggest use of information theoretic
measures for ranking the co-occurring terms selected, in order to improve retrieval efficiency …