Overview of Classification Subtask at NTCIR-5 Patent Retrieval Task

This paper describes Classification Subtask at NTCIR-5 Patent Retrieval Task. We perform two subtasks for patent classification using a multi-dimensional classification structure called “F-term (File Forming Term) classification system”. The first one is Theme Categorization Subtask, where each participant classifies a patent into technological fields called themes. The second one is F-term Categorization Subtask, where each participant classifies a patent, whose theme has been given, into multifaceted categories called F-terms. We overview the designs of these subtasks, the test collections produced, and the evaluation results.