SIFT: Grounding LLM Reasoning in Contexts via Stickers
Zihao Zeng, Xuyao Huang, Boxiu Li, Zhijie Deng
TL;DR
The paper addresses factual drift in LLM reasoning, where context is misinterpreted during multi-step inference. It introduces SIFT, a training-free framework that grounds reasoning in context by generating a Sticker from the query, producing two predictions (Sticker-only and Query+Sticker), and refining the Sticker via Forward Optimization and Inverse Generation until the predictions align. Across models from 3B to 100B+ and benchmarks such as GSM8K, MATH-500, GPQA-Diamond, and AIME2024, SIFT delivers consistent improvements, including a pass@1 gain on AIME2024 for DeepSeek-R1 from $78.33\%$ to $85.67\%$ and about a $1.03$ percentage-point boost on MATH-500 from a baseline of $97.3\%$, establishing a new open-source state-of-the-art. The approach also synergizes with Self-Consistency, demonstrates iterative optimization benefits, and relies on a clear Consensus Prediction strategy, all while avoiding additional training data. Code for SIFT is publicly available, enabling practitioners to adopt fact-grounded reasoning in diverse settings.
Abstract
This paper identifies the misinterpretation of the context can be a significant issue during the reasoning process of large language models, spanning from smaller models like Llama3.2-3B-Instruct to cutting-edge ones like DeepSeek-R1. For example, in the phrase "10 dollars per kilo," LLMs might not recognize that "per" means "for each," leading to calculation errors. We introduce a novel, post-training approach called **Stick to the Facts (SIFT)** to tackle this. SIFT leverages increasing inference-time compute to ground LLM reasoning in contexts. At the core of SIFT lies the *Sticker*, which is generated by the model itself to explicitly emphasize the key information within the context. Given the curated Sticker, SIFT generates two predictions -- one from the original query and one from the query augmented with the Sticker. If they differ, the Sticker is sequentially refined via *forward* optimization (to better align the extracted facts with the query) and *inverse* generation (to conform with the model's inherent tendencies) for more faithful reasoning outcomes. Studies across diverse models (from 3B to 100B+) and benchmarks (e.g., GSM8K, MATH-500) reveal consistent performance improvements. Notably, SIFT improves the pass@1 accuracy of DeepSeek-R1 on AIME2024 from 78.33% to **85.67**%, establishing a new state-of-the-art in the open-source community. The code is available at https://github.com/zhijie-group/SIFT.
