Can LMs Generalize to Future Data? An Empirical Analysis on Text Summarization
Chi Cheang, Hou Chan, Derek Wong, Xuebo Liu, Zhaocong Li, Yanming Sun, Shudong Liu, Lidia Chao
Abstract
Recent pre-trained language models (PLMs) achieve promising results in existing abstractive summarization datasets. However, existing summarization benchmarks overlap in time with the standard pre-training corpora and finetuning datasets. Hence, the strong performance of PLMs may rely on the parametric knowledge that is memorized during pre-training and fine-tuning. Moreover, the knowledge memorized by PLMs may quickly become outdated, which affects the generalization performance of PLMs on future data. In this work, we propose TempoSum, a novel benchmark that contains data samples from 2010 to 2022, to understand the temporal generalization ability of abstractive summarization models. Through extensive human evaluation, we show that parametric knowledge stored in summarization models significantly affects the faithfulness of the generated summaries on future data. Moreover, existing faithfulness enhancement methods cannot reliably improve the faithfulness of summarization models on future data. Finally, we discuss several recommendations to the research community on how to evaluate and improve the temporal generalization capability of text summarization models.- Anthology ID:
- 2023.emnlp-main.1007
- Volume:
- Proceedings of the 2023 Conference on Empirical Methods in Natural Language Processing
- Month:
- December
- Year:
- 2023
- Address:
- Singapore
- Editors:
- Houda Bouamor, Juan Pino, Kalika Bali
- Venue:
- EMNLP
- SIG:
- Publisher:
- Association for Computational Linguistics
- Note:
- Pages:
- 16205–16217
- Language:
- URL:
- https://aclanthology.org/2023.emnlp-main.1007
- DOI:
- 10.18653/v1/2023.emnlp-main.1007
- Cite (ACL):
- Chi Cheang, Hou Chan, Derek Wong, Xuebo Liu, Zhaocong Li, Yanming Sun, Shudong Liu, and Lidia Chao. 2023. Can LMs Generalize to Future Data? An Empirical Analysis on Text Summarization. In Proceedings of the 2023 Conference on Empirical Methods in Natural Language Processing, pages 16205–16217, Singapore. Association for Computational Linguistics.
- Cite (Informal):
- Can LMs Generalize to Future Data? An Empirical Analysis on Text Summarization (Cheang et al., EMNLP 2023)
- PDF:
- https://preview.aclanthology.org/corrections-2024-05/2023.emnlp-main.1007.pdf