Time period identification of events in text

  • Authors:
  • Taichi Noro;Takashi Inui;Hiroya Takamura;Manabu Okumura

  • Affiliations:
  • Tokyo Institute of Technology, Midori-ku, Yokohama, Kanagawa, Japan;Japan Society for the Promotion of Science;Tokyo Institute of Technology;Tokyo Institute of Technology

  • Venue:
  • ACL-44 Proceedings of the 21st International Conference on Computational Linguistics and the 44th annual meeting of the Association for Computational Linguistics
  • Year:
  • 2006

Quantified Score

Hi-index 0.00

Visualization

Abstract

This study aims at identifying when an event written in text occurs. In particular, we classify a sentence for an event into four time-slots; morning, daytime, evening, and night. To realize our goal, we focus on expressions associated with time-slot (time-associated words). However, listing up all the time-associated words is impractical, because there are numerous time-associated expressions. We therefore use a semi-supervised learning method, the Naïve Bayes classifier backed up with the Expectation Maximization algorithm, in order to iteratively extract time-associated words while improving the classifier. We also propose to use Support Vector Machines to filter out noisy instances that indicates no specific time period. As a result of experiments, the proposed method achieved 0.864 of accuracy and outperformed other methods.