Word-Label Alignment for Event Detection: A New Perspective via Optimal Transport

Amir Pouran Ben Veyseh, Thien Nguyen


Abstract
Event Detection (ED) aims to identify mentions/triggers of real world events in text. In the literature, this task is modeled as a sequence-labeling or word-prediction problem. In this work, we present a novel formulation in which ED is modeled as a word-label alignment task. In particular, given the words in a sentence and possible event types, the objective is to infer an alignment matrix in which event trigger words are aligned with the most likely event types. Moreover, we show that this new perspective facilitates the incorporation of word-label alignment biases to improve alignment matrix for ED. Novel alignment biases and Optimal Transport are introduced to solve our alignment problem for ED. We conduct experiments on a benchmark dataset to demonstrate the effectiveness of the proposed model for ED.
Anthology ID:
2022.starsem-1.11
Volume:
Proceedings of the 11th Joint Conference on Lexical and Computational Semantics
Month:
July
Year:
2022
Address:
Seattle, Washington
Editors:
Vivi Nastase, Ellie Pavlick, Mohammad Taher Pilehvar, Jose Camacho-Collados, Alessandro Raganato
Venue:
*SEM
SIG:
SIGLEX
Publisher:
Association for Computational Linguistics
Note:
Pages:
132–138
Language:
URL:
https://aclanthology.org/2022.starsem-1.11
DOI:
10.18653/v1/2022.starsem-1.11
Bibkey:
Cite (ACL):
Amir Pouran Ben Veyseh and Thien Nguyen. 2022. Word-Label Alignment for Event Detection: A New Perspective via Optimal Transport. In Proceedings of the 11th Joint Conference on Lexical and Computational Semantics, pages 132–138, Seattle, Washington. Association for Computational Linguistics.
Cite (Informal):
Word-Label Alignment for Event Detection: A New Perspective via Optimal Transport (Pouran Ben Veyseh & Nguyen, *SEM 2022)
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PDF:
https://aclanthology.org/2022.starsem-1.11.pdf