Question Answering Over Temporal Knowledge Graphs

Apoorv Saxena, Soumen Chakrabarti, Partha Talukdar


Abstract
Temporal Knowledge Graphs (Temporal KGs) extend regular Knowledge Graphs by providing temporal scopes (start and end times) on each edge in the KG. While Question Answering over KG (KGQA) has received some attention from the research community, QA over Temporal KGs (Temporal KGQA) is a relatively unexplored area. Lack of broad coverage datasets has been another factor limiting progress in this area. We address this challenge by presenting CRONQUESTIONS, the largest known Temporal KGQA dataset, clearly stratified into buckets of structural complexity. CRONQUESTIONS expands the only known previous dataset by a factor of 340x. We find that various state-of-the-art KGQA methods fall far short of the desired performance on this new dataset. In response, we also propose CRONKGQA, a transformer-based solution that exploits recent advances in Temporal KG embeddings, and achieves performance superior to all baselines, with an increase of 120% in accuracy over the next best performing method. Through extensive experiments, we give detailed insights into the workings of CRONKGQA, as well as situations where significant further improvements appear possible. In addition to the dataset, we have released our code as well.
Anthology ID:
2021.acl-long.520
Volume:
Proceedings of the 59th Annual Meeting of the Association for Computational Linguistics and the 11th International Joint Conference on Natural Language Processing (Volume 1: Long Papers)
Month:
August
Year:
2021
Address:
Online
Editors:
Chengqing Zong, Fei Xia, Wenjie Li, Roberto Navigli
Venues:
ACL | IJCNLP
SIG:
Publisher:
Association for Computational Linguistics
Note:
Pages:
6663–6676
Language:
URL:
https://aclanthology.org/2021.acl-long.520
DOI:
10.18653/v1/2021.acl-long.520
Bibkey:
Cite (ACL):
Apoorv Saxena, Soumen Chakrabarti, and Partha Talukdar. 2021. Question Answering Over Temporal Knowledge Graphs. In Proceedings of the 59th Annual Meeting of the Association for Computational Linguistics and the 11th International Joint Conference on Natural Language Processing (Volume 1: Long Papers), pages 6663–6676, Online. Association for Computational Linguistics.
Cite (Informal):
Question Answering Over Temporal Knowledge Graphs (Saxena et al., ACL-IJCNLP 2021)
Copy Citation:
PDF:
https://aclanthology.org/2021.acl-long.520.pdf
Video:
 https://aclanthology.org/2021.acl-long.520.mp4
Code
 apoorvumang/CronKGQA +  additional community code
Data
CronQuestionsComplexWebQuestionsMetaQASimpleQuestions