We investigate systems that identify opinion expressions and assigns polarities to the extracted expressions. In particular, we demonstrate the benefit of integrating opinion extraction and polarity classification into a joint model using features reflecting the global polarity structure. The model is trained using large-margin structured prediction methods. The system is evaluated on the MPQA opinion corpus, where we compare it to the only previously published end-to-end system for opinion expression extraction and polarity classification. The results show an improvement of between 10 and 15 absolute points in F-measure.
Titolo: | Extracting opinion expressions and their polarities – exploration of pipelines and joint models |
Autori: | Johansson, Bo Richard; Moschitti, Alessandro |
Autori Unitn: | |
Titolo del volume contenente il saggio: | HLT '11 Proceedings of the 49th Annual Meeting of the Association for Computational Linguistics: Human Language Technologies |
Luogo di edizione: | Portland, Oregon, USA |
Casa editrice: | Association for Computational Linguistics |
Anno di pubblicazione: | 2011 |
Codice identificativo Scopus: | 2-s2.0-84859048335 |
ISBN: | 978-1-932432-88-6 |
Handle: | http://hdl.handle.net/11572/89075 |
Appare nelle tipologie: | 04.1 Saggio in atti di convegno (Paper in proceedings) |