An Axiomatic Approach to Exploit Term Dependencies in Language Model

One of important problems of dependence retrieval model is the challenge to integrate both single words and dependencies in one weighting schema. Although there are many retrieval models that exploit term dependencies in language modeling framework, seldom of them simultaneously study the problem on different query types, e.g., short queries and verbose queries. In this paper, we derive an axiomatic dependence model by defining several basic desirable constraints that a retrieval model should meet. The experiment results show that our model significantly and robustly improves retrieval accuracy over the baseline (unigram model) in verbose queries and achieves better performance than some state-of-art dependence models.