In the language modeling approach to information retrieval, the relevance of a targeted question to a queried question is given by the probability | of generating the queried question Following the framework, we propose a mixture model for modeling question structure (namely, question topic and question focus) within the process of searching questions: In the mixture model, it is assumed that the process of generating question topics and the process of generating question foci are independent from each other.
the evaluation was conducted with exactly the same setting as in Section 3.