Inference to the Best Explanation in Large Language Models

Dhairya Dalal, Marco Valentino, Andre Freitas, Paul Buitelaar


Abstract
While Large Language Models (LLMs) have found success in real-world applications, their underlying explanatory process is still poorly understood. This paper proposes IBE-Eval, a framework inspired by philosophical accounts on Inference to the Best Explanation (IBE) to advance the interpretation and evaluation of LLMs’ explanations. IBE-Eval estimates the plausibility of natural language explanations through a combination of explicit logical and linguistic features including: consistency, parsimony, coherence, and uncertainty. Extensive experiments are conducted on Causal Question Answering (CQA), where IBE-Eval is tasked to select the most plausible causal explanation amongst competing ones generated by LLMs (i.e., GPT 3.5 and Llama 2). The experiments reveal that IBE-Eval can successfully identify the best explanation with up to 77% accuracy (≈ 27% above random), improving upon a GPT 3.5-as-a-Judge baseline (≈+17%) while being intrinsically more efficient and interpretable. Additional analyses suggest that, despite model-specific variances, LLM-generated explanations tend to conform to IBE criteria and that IBE-Eval is significantly correlated with human judgment, opening up opportunities for future development of automated explanation verification tools.
Anthology ID:
2024.acl-long.14
Volume:
Proceedings of the 62nd Annual Meeting of the Association for Computational Linguistics (Volume 1: Long Papers)
Month:
August
Year:
2024
Address:
Bangkok, Thailand
Editors:
Lun-Wei Ku, Andre Martins, Vivek Srikumar
Venue:
ACL
SIG:
Publisher:
Association for Computational Linguistics
Note:
Pages:
217–235
Language:
URL:
https://aclanthology.org/2024.acl-long.14
DOI:
10.18653/v1/2024.acl-long.14
Bibkey:
Cite (ACL):
Dhairya Dalal, Marco Valentino, Andre Freitas, and Paul Buitelaar. 2024. Inference to the Best Explanation in Large Language Models. In Proceedings of the 62nd Annual Meeting of the Association for Computational Linguistics (Volume 1: Long Papers), pages 217–235, Bangkok, Thailand. Association for Computational Linguistics.
Cite (Informal):
Inference to the Best Explanation in Large Language Models (Dalal et al., ACL 2024)
Copy Citation:
PDF:
https://aclanthology.org/2024.acl-long.14.pdf