P. van der Weide. Phrase-based Information Retrieval . In other words, we focus on the representation of index expressions rather than on linguistic aspects. Index expressions are still somewhat restricted, especially as cumulative representations and when combinations and exclusions are to be modeled. Tractability Tractability, or simplicity of being processed, is viewed as a system criterion.
Tractability is inversely proportional to the diculty to solve a problem.
P. van der Weide. Phrase-based Information Retrieval . Indeed , many researchers have developed such techniques. This paper discusses a retrieval schema which attempts to overcome the problems originating from the Keyword Retrieval Hypothesis and linguistic variation. First, in section 2 we will review some of the most important attempts made to deal with linguistic variation.