Experiments of Opinion Analysis on the Corpora MPQA and NTCIR-6

This paper describes the algorithms and linguistic features used in our participating system for the opinion analysis pilot task at NTCIR-6. It presents and discusses the results of our system on the opinion analysis task. It also presents our experiments of opinion analysis on the two corpora MPQA and NTCIR-6, by using our learning based system. Our system was base on the SVM learning. It achieved state of the art results on the MPQA corpus for the two problems, opinionated sentence recognition and opinion holder extraction. The results using the NTCIR-6 English corpus for both training and testing are certainly among the first ones. Our results on the opinionated sentence recognition sub-task of the NTCIR-6 were encouraging. The results on the English evaluation of the NTCIR-6 opinion analysis task were obtained from the models learned from the MPQA corpus. The lower results on the NTCIR-6 opinion holder extraction subtask, in comparison with those using each corpus for both training and testing, may possibly show that there exist substantial differences between the MPQA corpus and the NTCIR-6 English corpus.