Microsoft Research Asia at the NTCIR-9 Intent Task

In NTCIR-9, we participate in the Intent task, including both the Subtopic Mining subtask and the Document Ranking subtask. In the Subtopic Mining subtask, we mine subtopics from query logs and top results of the queries, and rank them based on their relevance to the query and the similarity between them. In the Document ranking Subtask, we diversify top search results using the mined subtopics based on a general multi-dimensional diversification framework. Experimental results show that our best Chinese subtopic mining run is ranked No. 2 of all 42 runs in terms of D nDCG@10. Our Chinese document ranking runs generally outperform other runs in terms of I-rec. Our best Chinese document ranking runs is the No. 4 of all 24 runs in terms of D nDCG@10. Our Japanese document ranking runs perform the best both in terms of D-nDCG and in terms of D-nDCG.