Overview of Multilingual Opinion Analysis Task at NTCIR-7.

Abstract

This paper describes an overview of the Multilingual Opinion Analysis Task from 2007 to 2008 at the Seventh NTCIR Workshop. We created test collections of 22, 17, 17, 16 topics (7,163, 4,711, 6,174, and 5,301 sentences) in Japanese, English, Traditional Chinese, and Simplified Chinese. Using this test collection, we conducted five subtasks: (1) mandatory opinionated sentence judgment, and optional subtasks of (2) relevant sentence judgment, (3) polarity judgment, (4) opinion holder extraction, and (5) opinion target extraction. 32 results were submitted from 21 participants with five results submitted by the organizers. In this paper we present the task definition, the details of the test collection, the evaluation results of the groups that participated in this task, and their approach.