Answer-Consistent Chain-of-thought Reinforcement Learning For Multi-modal Large Langauge Models

Fuente: arXiv
Salvato in:
Dettagli Bibliografici
Autori principali: Huang, Minbin, Huang, Runhui, Zheng, Chuanyang, Li, Jingyao, Chen, Guoxuan, Shi, Han, Cheng, Hong
Natura: Preprint
Pubblicazione: 2025
Soggetti:
Accesso online:
Tags: Aggiungi Tag
Nessun Tag, puoi essere il primo ad aggiungerne!!
_version_ 1866908587622662144
author Huang, Minbin
Huang, Runhui
Zheng, Chuanyang
Li, Jingyao
Chen, Guoxuan
Shi, Han
Cheng, Hong
author_facet Huang, Minbin
Huang, Runhui
Zheng, Chuanyang
Li, Jingyao
Chen, Guoxuan
Shi, Han
Cheng, Hong
contents Recent advances in large language models (LLMs) have demonstrated that reinforcement learning with verifiable rewards (RLVR) can significantly enhance reasoning abilities by directly optimizing correctness, rather than relying solely on supervised imitation. This paradigm has been extended to multimodal LLMs for complex video and image understanding tasks. However, while outcome-driven RL improves answer accuracy, it can inadvertently decouple the reasoning chain from the final answer, leading to situations where models produce inconsistency between the reasoning trace and final answer. In our experiments on multiple-choice visual question-answering tasks, the standard GRPO method yields only 79.7\% consistency on MMVU between the reasoning steps and the chosen answers, indicating frequent mismatches between answers and reasoning. To this end, we propose Answer-Consistent Reinforcement Learning (ACRE) that modifies the GRPO algorithm with an auxiliary consistency check. After the model generates a chain of thought and an initial answer for a given question, we shuffle the answer options and prompt the model again with the same reasoning trace to predict a second answer. We design a consistency-verification reward that grants a high reward only if both the original and the post-shuffle answers agree and are correct; otherwise, a lower reward is assigned accordingly. This mechanism penalizes reasoning-answer misalignment and discourages the model from relying on spurious patterns, such as option ordering biases. We evaluate ACRE on challenging Video Reasoning benchmarks and multimodal math reasoning benchmarks, achieving an average 2.2\% and 1.5\% improvement for Video Reasoning and Math Reasoning tasks over the GRPO baseline.
format Preprint
id arxiv_https___arxiv_org_abs_2510_10104
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Answer-Consistent Chain-of-thought Reinforcement Learning For Multi-modal Large Langauge Models
Huang, Minbin
Huang, Runhui
Zheng, Chuanyang
Li, Jingyao
Chen, Guoxuan
Shi, Han
Cheng, Hong
Computer Vision and Pattern Recognition
Recent advances in large language models (LLMs) have demonstrated that reinforcement learning with verifiable rewards (RLVR) can significantly enhance reasoning abilities by directly optimizing correctness, rather than relying solely on supervised imitation. This paradigm has been extended to multimodal LLMs for complex video and image understanding tasks. However, while outcome-driven RL improves answer accuracy, it can inadvertently decouple the reasoning chain from the final answer, leading to situations where models produce inconsistency between the reasoning trace and final answer. In our experiments on multiple-choice visual question-answering tasks, the standard GRPO method yields only 79.7\% consistency on MMVU between the reasoning steps and the chosen answers, indicating frequent mismatches between answers and reasoning. To this end, we propose Answer-Consistent Reinforcement Learning (ACRE) that modifies the GRPO algorithm with an auxiliary consistency check. After the model generates a chain of thought and an initial answer for a given question, we shuffle the answer options and prompt the model again with the same reasoning trace to predict a second answer. We design a consistency-verification reward that grants a high reward only if both the original and the post-shuffle answers agree and are correct; otherwise, a lower reward is assigned accordingly. This mechanism penalizes reasoning-answer misalignment and discourages the model from relying on spurious patterns, such as option ordering biases. We evaluate ACRE on challenging Video Reasoning benchmarks and multimodal math reasoning benchmarks, achieving an average 2.2\% and 1.5\% improvement for Video Reasoning and Math Reasoning tasks over the GRPO baseline.
title Answer-Consistent Chain-of-thought Reinforcement Learning For Multi-modal Large Langauge Models
topic Computer Vision and Pattern Recognition
url https://arxiv.org/abs/2510.10104