Timeline Summarization based on Event Graph Compression via Time-Aware Optimal Transport

Manling Li, Tengfei Ma, Mo Yu, Lingfei Wu, Tian Gao, Heng Ji, Kathleen McKeown


Abstract
Timeline Summarization identifies major events from a news collection and describes them following temporal order, with key dates tagged. Previous methods generally generate summaries separately for each date after they determine the key dates of events. These methods overlook the events’ intra-structures (arguments) and inter-structures (event-event connections). Following a different route, we propose to represent the news articles as an event-graph, thus the summarization becomes compressing the whole graph to its salient sub-graph. The key hypothesis is that the events connected through shared arguments and temporal order depict the skeleton of a timeline, containing events that are semantically related, temporally coherent and structurally salient in the global event graph. A time-aware optimal transport distance is then introduced for learning the compression model in an unsupervised manner. We show that our approach significantly improves on the state of the art on three real-world datasets, including two public standard benchmarks and our newly collected Timeline100 dataset.
Anthology ID:
2021.emnlp-main.519
Volume:
Proceedings of the 2021 Conference on Empirical Methods in Natural Language Processing
Month:
November
Year:
2021
Address:
Online and Punta Cana, Dominican Republic
Editors:
Marie-Francine Moens, Xuanjing Huang, Lucia Specia, Scott Wen-tau Yih
Venue:
EMNLP
SIG:
Publisher:
Association for Computational Linguistics
Note:
Pages:
6443–6456
Language:
URL:
https://aclanthology.org/2021.emnlp-main.519
DOI:
10.18653/v1/2021.emnlp-main.519
Bibkey:
Cite (ACL):
Manling Li, Tengfei Ma, Mo Yu, Lingfei Wu, Tian Gao, Heng Ji, and Kathleen McKeown. 2021. Timeline Summarization based on Event Graph Compression via Time-Aware Optimal Transport. In Proceedings of the 2021 Conference on Empirical Methods in Natural Language Processing, pages 6443–6456, Online and Punta Cana, Dominican Republic. Association for Computational Linguistics.
Cite (Informal):
Timeline Summarization based on Event Graph Compression via Time-Aware Optimal Transport (Li et al., EMNLP 2021)
Copy Citation:
PDF:
https://aclanthology.org/2021.emnlp-main.519.pdf
Video:
 https://aclanthology.org/2021.emnlp-main.519.mp4
Code
 limanling/event-graph-summarization