Natural language research announcements

["Alexandre Klementiev" <klementi AT uiuc.edu>]

Title: Recent
Advances in Word Sense Disambiguation: Scaling Up, Sense Prior
Estimation, and Integration into Statistical Machine Translation 

Speaker: Dr. Hwee Tou Ng, Department of Computer Science, National University of Singapore

Date: June 13, 4:30pm
Location: Siebel 2405 

Abstract: 

In this talk, I will introduce several research issues associated with word sense disambiguation (WSD), which is the task of determining the correct meaning, or sense, of a word in context. I will present recent work completed in my research group to address these issues. The first issue concerns the scaling up of WSD. Although supervised WSD gives good accuracy, the lack of sense-tagged training data has hampered the progress of WSD. I will present our approach of using parallel texts to scale up WSD. Using this approach, our WSD system participated in SemEval-2007, where our system achieved the highest and second highest accuracy in the coarse-grained and fine-grained English all-words task, among 16 and 14 participating systems respectively. The second issue concerns the accuracy drop of a WSD system, when it is applied to texts drawn from a different domain with different sense priors. I will present results showing improved WSD accuracy after applying class prior estimation algorithms and using well calibrated probabilities. The third issue concerns the perceived lack of applications utilizing WSD. We integrated our state-of-the-art WSD system into Hiero, a state-of-the-art hierarchical phrase-based statistical machine translation system. We found that the use of WSD improves translation quality, and the improvement is statistically significant.

Bio:

Dr. Hwee Tou NG is an Associate Professor of Computer Science at the National University of Singapore, Program Co-chair (Computer Science Program) of the Singapore-MIT Alliance, and a Senior Faculty Member at the NUS Graduate School for Integrative Sciences and Engineering. He received a PhD in Computer Science from the University of Texas at Austin, USA in 1992.

His research focuses on natural language processing and information retrieval. He has published papers in premier journals and conferences including Computational Linguistics, ACL, EMNLP, SIGIR, AAAI, and IJCAI. He is the Editor-in-Chief of ACM Transactions on Asian Language Information Processing (TALIP), and an editorial board member of Natural Language Engineering journal. He has also served as an editorial board member of Computational Linguistics journal (2004 - 2006). He is an elected member of the ACL executive committee (2008 - 2010) and a steering committee member and former secretary of ACL SIGNLL. He is program co-chair of EMNLP 2008 conference, was program co-chair of ACL-2005 and CoNLL-2004 conferences, and has served on the program committees of many past conferences including ACL, EMNLP, SIGIR, AAAI, and IJCAI.