aiqbench analysis
This research introduces LIFT, a method that automatically enhances the faithfulness of chain-of-thought reasoning in large language models by identifying and reinforcing causally influential steps without requiring human annotations. By fine-tuning on traces where irrelevant interventions disrupted reasoning, the approach successfully aligns stated logic with actual model behavior across multiple architectures while maintaining high accuracy. This advancement addresses a critical reliability issue in CoT systems, making them more interpretable and trustworthy for complex problem-solving tasks.
LIFT: Likelihood-Based Intervention Faithfulness Training
arXiv:2509.13334v2 Announce Type: replace Abstract: Chain-of-thought (CoT) reasoning improves LLM accuracy on complex tasks, but CoTs are often unfaithful; that is, the model does not rely on the stated reasoning steps to produce its answer. Existing methods to improve faithfulness require human annotations. We propose LIFT, which automatically scores each reasoning step by its causal influence: we replace it with a domain-matched but irrelevant fact and measure the drop in answer log-probability. We fine-tune on high-scoring CoT traces where interventions successfully disrupted reasoning, jointly optimizing for faithfulness and accuracy. LIFT improves faithfulness across three models (Mistral-7B-Instruct, Qwen3-8B, and Qwen3-4B-Instruct) and three benchmarks, with accuracy comparable to a model fine-tuned solely for accuracy.
Abstract:Chain-of-thought (CoT) reasoning improves LLM accuracy on complex tasks, but CoTs are often unfaithful; that is, the model does not rely on the stated reasoning steps to produce its answer. Existing methods to improve faithfulness require human annotations. We propose LIFT, which automatically scores each reasoning step by its causal influence: we replace it with a domain-matched but irrelevant fact and measure the drop in answer log-probability. We fine-tune on high-scoring CoT traces where interventions successfully disrupted reasoning, jointly optimizing for faithfulness and accuracy. LIFT improves faithfulness across three models (Mistral-7B-Instruct, Qwen3-8B, and Qwen3-4B-Instruct) and three benchmarks, with accuracy comparable to a model fine-tuned solely for accuracy.
Artificial Intelligence (cs.AI); Machine Learning (cs.LG)
arXiv:2509.13334 [cs.AI]
(or arXiv:2509.13334v2 [cs.AI] for this version)
https://doi.org/10.48550/arXiv.2509.13334 Focus to learn more arXiv-issued DOI via DataCite
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Full text under the publisher's open licence · 202 words
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