思维链 vs 思维树：该用哪个
CoT和ToT是两大推理技术，但适用不同问题。
Chain of Thought vs Tree of Thought: Which Reasoning Technique Should You Use in 2026
Chain of Thought (Wei et al., 2022) and Tree of Thought (Yao et al., 2023) both make LLMs reason more carefully - but they are built for different kinds of problems. Understanding the difference saves you tokens and improves accuracy.
The Core Difference
Chain of Thought (CoT): The model produces one linear chain of reasoning, then answers. One path, sequential.
Step 1 -> Step 2 -> Step 3 -> Answer
Tree of Thought (ToT): The model generates multiple reasoning branches at each step, evaluates them, and explores the most promising. Multiple paths, with backtracking.
When to Use Which
| Problem type | Technique | Why |
|---|---|---|
| Math, arithmetic | CoT | Single correct path, linear reasoning |
| Logic puzzles | CoT | Step-by-step suffices |
| Open-ended planning | ToT | Explore many options |
| Creative writing | ToT | Branch into different directions |
| Debugging | CoT | Trace one hypothesis at a time |
| Strategy/games | ToT | Evaluate moves before committing |
| Short answers | CoT | Cheap and effective |
| Complex reasoning with dead ends | ToT | Backtracking avoids traps |
Cost Comparison
| Technique | Tokens | Latency | Best model size |
|---|---|---|---|
| Direct answer | 1x | Fast | Any |
| CoT | 3-5x | Medium | 7B+ |
| ToT | 10-30x | Slow | 30B+ or API |
How to Implement ToT Without a Framework
A minimal loop: ask the model for 3 candidate next steps, score each with a second prompt ("rate this step 1-10"), keep the best, repeat 3-5 times. That is ToT in plain Python - no framework needed.
FAQ
Is ToT always better? No. For well-defined problems with a single correct path, CoT is cheaper and equally accurate. ToT shines when branches exist and dead ends are common.
Do modern models still need these techniques? Yes - even GPT-5-class models improve on hard tasks with explicit reasoning scaffolding, though newer models do more internal reasoning natively.
Which should a beginner learn first? CoT. It is simpler, cheaper, and covers 80% of practical cases.
