Budget-Aware Anytime Reasoning with LLM-Synthesized Preference Data
Xuanming Zhang, Shwan Ashrafi, Aziza Mirsaidova, Amir Rezaeian, Miguel Ballesteros, Lydia B. Chilton, Zhou Yu, Dan Roth
TL;DR
This work tackles budget-aware reasoning by formalizing anytime reasoning and introducing the Anytime Index to quantify how quickly reasoning quality improves with more tokens. It couples this evaluation with an inference-time self-improvement method, Preference Data Prompting (PDP), which uses LLM-generated, contrastive reasoning pairs to guide intermediate steps without human labeling. Across NaturalPlan, AIME, and GPQA, PDP improves both intermediate and final performance and generally yields higher Anytime Indices across diverse models, including Grok-3, GPT-oss, GPT-4.1/4o, and Llama-3.3-70B, demonstrating that models can become faster and more reliable anytime reasoners under token budgets. The approach offers practical benefits for real-world deployments where latency and compute budgets constrain full deliberation, and it lays the groundwork for further training-time improvements and broader domain validation.
Abstract
We study the reasoning behavior of large language models (LLMs) under limited computation budgets. In such settings, producing useful partial solutions quickly is often more practical than exhaustive reasoning, which incurs high inference costs. Many real-world tasks, such as trip planning, require models to deliver the best possible output within a fixed reasoning budget. We introduce an anytime reasoning framework and the Anytime Index, a metric that quantifies how effectively solution quality improves as reasoning tokens increase. To further enhance efficiency, we propose an inference-time self-improvement method using LLM-synthesized preference data, where models learn from their own reasoning comparisons to produce better intermediate solutions. Experiments on NaturalPlan (Trip), AIME, and GPQA datasets show consistent gains across Grok-3, GPT-oss, GPT-4.1/4o, and LLaMA models, improving both reasoning quality and efficiency under budget constraints.
