Article URL: https://magazine.sebastianraschka.com/p/controlling-reasoning-effort-in-llms Comments URL: https://news.ycombinator.com/item?id=48979475 Points: 9 # Comments: 0

It has been almost two years since OpenAI released o1, a model that popularized the idea of LLM-based reasoning models. DeepSeek-R1 followed about four months later, together with details of a reinforcement learning with verifiable rewards (RLVR) recipe to train such reasoning models. Last week, OpenAI released the GPT-5.6 model family. It comes in three sizes, each with roughly five or six reasoning-effort settings. So yes, reasoning models are here to stay. They have become a standard part of modern model releases. In the past, I covered the methodology of reasoning models (Understanding Reasoning LLMs) as well as relevant research papers (The State of Reinforcement Learning for LLM Reasoning and The State of LLM Reasoning Model Inference). And I even wrote a whole new 440-page book on how to develop reasoning models, Build A Reasoning Model (From Scratch). These resources have focused on turning a conventional LLM into a reasoning model. Now, in this article, I want to focus on and explain how to develop a reasoning model that has multiple effort modes, similar to what’s shown in the figure at the beginning of this article. No worries, this article can be read as a standalone article. However, the aforementioned resources may be interesting and useful. When talking about pretty much any machine learning or AI technique or subfield, the one lesson is that we usually shouldn’t take technical terms “literally”. For example, an (artificial) neural network in machine learning and AI doesn’t literally work like a biological neural network like the human brain. Similarly, when talking about “reasoning models”, we shouldn’t expect that these models literally reason like us humans. In the context of AI and LLM research, “reasoning model” means a model that outputs an intermediate reasoning trace, which is like an intermediate response that works through a question or task step by step.