HIT2 Joint NLP Lab at the NTCIR-9 Intent Task

The report hereby is to represent the principle, the searching process and experiment results. We report our systems and experiments in the intent task of NTCIR 9. The research aims at evaluating the effectiveness of the proposed methods on query intent mining and results diversification in terms of web search. In the subtopic mining subtask, we combine the extracted candidates from search logs and Wikipedia. An improvement could be seen after incorporating query intents from different resources. In the document ranking subtask, greedy algorithms are taken to select documents with the high diversified score and return a re-ranked list of diversified documents based on query subtopics. The experiment results show that the method, that is combining subtopic results directly, outperforms MMR.