The Report on Subtopic Mining and Document Ranking of NTCIR-9 Intent Task

In this paper we report our approach and result as a participant of the NTCIR-9 Intent task. INTENT task is a new NTCIR task which consists of two subtasks: (1) Subtopic Mining subtask: given a query, a system lists all possible subtopics that might cover users’ different intents. Our approach is mining the query log to find subtopics candidates and rank them according to the frequencies of each candidate. (2) Document Ranking subtask: given a query, a system returns diversified document URLs that might cover users’ diversified intents. Since the document set is larger than the capacity of PC. Our approach is to construct a distributed framework that can search a partial document set by one PC at a time and merge the partial search results to get the final ranking list.