A first step towards flexible local feedback for ad hoc retrieval
Tetsuya Sakai, Masahiro Kajiura, Kazuo Sumita · 2000
Local feedback for ad hoc retrieval typically hurts performance for about one-third of the search requests while improving the average performance. Our objective is to make it more reliable by estimating the optimal number of assumed-relevant documents and the optimal number of expansion terms for each request. We examine some simple optimization methods based on: the number of case particles in the request; the number of initial search terms; the highest document score in the initial ranked output; and the document score curves. Unfortunately, our first results using the BMIR-J2 and IREX Japanese test collections are negative. We are currently exploring some modified strategies for solving the optimization problems.