跳到主要内容Skip to main content

思维链Chain of Thought (CoT)

Chain of Thought (CoT)

  • 核心概念Core concepts
  • 第四站 · 看懂Station 4 · Under the Hood
解决什么问题What problem it solves

让模型先列推理步骤再给答案的提示方式,以及它对模型规模的依赖。Prompting the model to lay out reasoning steps before answering — and its dependence on model scale.

这是什么What it is

Wei 等人提出:在示例中给出若干中间推理步骤,可显著提升足够大的模型的推理表现。

PaLM 540B 仅用 8 个思维链示例。它在 GSM8K 数学题上达到当时最优。

该文同时指出思维链是规模的涌现能力:约 10B 以下的小模型上反而降低性能。

小模型会产出「流畅但无逻辑」的推理链。

Wei et al. showed that a few chain-of-thought exemplars markedly improve reasoning in sufficiently large models.

PaLM 540B with just eight exemplars reached state-of-the-art accuracy on the GSM8K math benchmark.

The same paper shows CoT is an emergent ability of scale: it hurts models below roughly 10B parameters.

Small models produce fluent but illogical chains of thought.

为什么需要知道Why it matters

「让模型一步步想」对小模型可能有害。知道规模门槛,才知道这招什么时候该用、什么时候是自我安慰。'Make the model think step by step' can backfire on small models. Knowing the scale threshold tells you when the trick works and when it is self-comfort.

出处Sources
  • Wei 等《Chain-of-Thought Prompting Elicits Reasoning in Large Language Models》Wei et al., Chain-of-Thought Prompting (NeurIPS 2022) ↗