Diving into the Inter-Consistency of Large Language Models: An Insightful Analysis through Debate

Large language models (LLMs) have demonstrated impressive zero-shot or few-shot commonsense reasoning performance on various natural language processing (NLP) tasks. However, despite their strong commonsense reasoning abilities, LLMs still exhibit various kinds of inconsistency problems. While previous researches mainly focused on the self-consistency within a single LLM, we propose to explore the inter-consistency issue between two or more LLMs, which is critical for diverse and precise decision-making processes. Since the LLMs possess human-like intelligence after instruction tuning and reinforcement learning with human feedback (RLHF), we design a formal debate framework to delve into the inter-consistency problem among LLMs with three-stage debate: fair debate, mismatched debate, and roundtable debate. Through extensive experiments on 7 commonsense reasoning datasets, LLMs not only become more inter-consistent by compromising and refuting but also achieve higher performance and stronger interpretability. Furthermore, we find a much stronger LLM would be dominant in mismatched debates, while it will be easily misled by relatively weaker LLMs in a more complex debate scenario such as roundtable debate.