Abstract
Knowing the reasoning chains from knowledge to the predicted answers can help construct an explainable question answering (QA) system. Advances on QA explanation propose to explain the answers with entailment trees composed of multiple entailment steps. While current work proposes to generate entailment trees with end-to-end generative models, the steps in the generated trees are not constrained and could be unreliable. In this paper, we propose METGEN, a Module-based Entailment Tree GENeration framework that has multiple modules and a reasoning controller. Given a question and several supporting knowledge, METGEN can iteratively generate the entailment tree by conducting single-step entailment with separate modules and selecting the reasoning flow with the controller. As each module is guided to perform a specific type of entailment reasoning, the steps generated by METGEN are more reliable and valid. Experiment results on the standard benchmark show that METGEN can outperform previous state-of-the-art models with only 9% of the parameters.- Anthology ID:
- 2022.findings-naacl.145
- Volume:
- Findings of the Association for Computational Linguistics: NAACL 2022
- Month:
- July
- Year:
- 2022
- Address:
- Seattle, United States
- Editors:
- Marine Carpuat, Marie-Catherine de Marneffe, Ivan Vladimir Meza Ruiz
- Venue:
- Findings
- SIG:
- Publisher:
- Association for Computational Linguistics
- Note:
- Pages:
- 1887–1905
- Language:
- URL:
- https://aclanthology.org/2022.findings-naacl.145
- DOI:
- 10.18653/v1/2022.findings-naacl.145
- Cite (ACL):
- Ruixin Hong, Hongming Zhang, Xintong Yu, and Changshui Zhang. 2022. METGEN: A Module-Based Entailment Tree Generation Framework for Answer Explanation. In Findings of the Association for Computational Linguistics: NAACL 2022, pages 1887–1905, Seattle, United States. Association for Computational Linguistics.
- Cite (Informal):
- METGEN: A Module-Based Entailment Tree Generation Framework for Answer Explanation (Hong et al., Findings 2022)
- PDF:
- https://preview.aclanthology.org/nschneid-patch-4/2022.findings-naacl.145.pdf
- Code
- Raising-hrx/MetGen + additional community code
- Data
- EntailmentBank, OpenBookQA, QASC, eQASC