An exploration of axiomatic approaches to information retrieval

Existing retrieval models generally do not offer any guarantee for optimal retrieval performance. Indeed, it is even difficult, if not impossible, to predict a model's empirical performance analytically. This limitation is at least partly caused by the way existing retrieval models are developed where relevance is only coarsely modeled at the level of documents and queries as opposed to a finer granularity level of terms. In this paper, we present a new axiomatic approach to developing retrieval models based on direct modeling of relevance with formalized retrieval constraints defined at the level of terms. The basic idea of this axiomatic approach is to search in a space of candidate retrieval functions for one that can satisfy a set of reasonable retrieval constraints. To constrain the search space, we propose to define a retrieval function inductively and decompose a retrieval function into three component functions. Inspired by the analysis of the existing retrieval functions with the inductive definition, we derive several new retrieval functions using the axiomatic retrieval framework. Experiment results show that the derived new retrieval functions are more robust and less sensitive to parameter settings than the existing retrieval functions with comparable optimal performance.