No Global Plan in Chain-of-Thought: Uncover the Latent Planning Horizon of LLMs
- •Tencent introduces Tele-Lens to probe the internal planning dynamics of Large Language Models.
- •Study reveals LLMs exhibit a myopic horizon, focusing on incremental steps rather than global strategies.
- •Probing method improves uncertainty estimation and identifies redundant reasoning steps for efficient bypass.
For years, researchers have debated whether Large Language Models (LLMs) actually "plan" their reasoning or simply predict the next most likely word. This new study from Tencent dives into the hidden layers of these models using a novel probing method called Tele-Lens. By examining internal states during complex tasks, researchers uncovered how far ahead an AI actually thinks before it speaks.
The findings challenge the notion of a "master plan" within AI reasoning. Instead of a holistic global strategy, the models exhibit a "myopic horizon," meaning they focus on incremental, step-by-step transitions rather than a fully mapped-out path to the solution. While they do anticipate immediate next steps (latent planning), their foresight is remarkably short-lived. This explains why explicit Chain-of-Thought remains so vital for multi-stage problem-solving.
Beyond theory, the team applied these findings to solve practical reliability issues. By identifying where a model is most "short-sighted," they improved uncertainty estimation—helping the AI know when it is likely to be wrong. They also demonstrated that certain reasoning steps can be bypassed without losing accuracy, paving the way for more efficient inference in future models.