CARE-STaR: Constraint-aware Self-taught Reasoner

In real-world applications, large language models (LLMs) often need to handle diverse and complex instructions.Specifically, when instructions are subject to multiple constraints, some of which are somewhat ambiguous, LLMs often fail to produce answers that satisfy all constraints, limiting their effectiveness in various tasks.To address this challenge, we examine the different constraints in the instructions and discover that the difficulty of determining whether an answer meets a constraint varies widely, from extremely straightforward to exceptionally perplexing.Correspondingly, we propose to assign constraints to different constraint levels.Furthermore, inspired by chain-of-thought (CoT) and selftaught reasoner (STaR), we propose a twostage method named CARE-STaR (Constraint-AwaRE STaR).Our method distinguishes constraints within instructions by generating different CoTs and guides LLMs to autonomously learn optimal answers by setting positive rewards for the CoTs that are beneficial to generating accurate answers and iteratively optimizing these answers.We have conducted extensive experiments on three instruction-following benchmarks, taking three existing LLMs as base LLMs, respectively.Experimental results indicate that our method substantially enhances the capability of these LLMs to handle complex instructions, outperforming supervised fine-tuning (SFT).Our code is available at https://github.com/lzl0124/carestar.