CLOMO: Counterfactual Logical Modification with Large Language Models
Yinya Huang, Ruixin Hong, Hongming Zhang, Wei Shao, Zhicheng Yang, Dong Yu, Changshui Zhang, Xiaodan Liang, Linqi Song
TL;DR
This work investigates counterfactual reasoning in large language models through the Counterfactual Logical Modification (CLOMO) framework. It introduces the CFLogic benchmark and a logic-aware evaluation framework based on $ V$-information, including the Pointwise $ V$-information (PVI) and Self-Evaluation Scores (SES) to assess how edits affect logical relationships. Experiments with GPT-3.5 and GPT-4 show that models can imitate some counterfactual patterns but lag behind human performance, and SES- and context-based metrics only partially align with human judgments. The study additionally discusses how strengthening counterfactual logical thinking may help reduce LLM hallucinations, with code and data available at the project repository for reproducibility and further research.
Abstract
In this study, we delve into the realm of counterfactual reasoning capabilities of large language models (LLMs). Our primary objective is to cultivate the counterfactual thought processes within LLMs and rigorously assess these processes for their validity. Specifically, we introduce a novel task, Counterfactual Logical Modification (CLOMO), and a high-quality human-annotated benchmark. In this task, LLMs must adeptly alter a given argumentative text to uphold a predetermined logical relationship. To effectively evaluate a generation model's counterfactual capabilities, we propose an innovative evaluation metric, the decomposed Self-Evaluation Score (SES) to directly evaluate the natural language output of LLMs instead of modeling the task as a multiple-choice problem. Analysis shows that the proposed automatic metric aligns well with human preference. Our experimental results show that while LLMs demonstrate a notable capacity for logical counterfactual thinking, there remains a discernible gap between their current abilities and human performance. Code and data are available at https://github.com/Eleanor-H/CLOMO.
