NTU Approaches to Subtopic Mining and Document Ranking at NTCIR-9 Intent Task.
Chieh-Jen Wang, Yung-Wei Lin, Ming-Feng Tsai, Hsin‐Hsi Chen · 2011
Users express their information needs in terms of queries to find the relevant documents on the web. However, users ’ queries are usually short, so that search engines may not have enough information to determine their exact intents. How to diversify web search results to cover users ’ possible intents as wide as possible is an important research issue. In this paper, we will propose several subtopic mining approaches and show how to diversify the search results by the mined subtopics. For Subtopic Mining subtask, we explore various subtopic mining algorithms that mine subtopics of a query from enormous documents on the web. For Document Ranking subtask, we propose re-ranking algorithms that keep the top-ranked results to contain as many popular subtopics as possible. The re-ranking algorithms apply sub-topics mined from subtopic mining algorithms to diversify the search results. The best performance of our system achieves an I-