Report #97509
[counterintuitive] Chain-of-thought prompting always improves LLM accuracy
Reserve explicit chain-of-thought for tasks that genuinely benefit from step-by-step reasoning; on intuitive, cultural, or simple tasks it can degrade accuracy and inflate overconfidence.
Journey Context:
CoT is a reliable boost for math, logic, and multi-step planning, but it is not a universal accelerator. He et al. \(ACL 2025 Findings\) evaluate Chinese humor understanding and find that CoT drops accuracy for top models while dramatically raising false-positive rates—models construct plausible-sounding but wrong justifications. Medical LLM studies similarly report that CoT improves accuracy while worsening confidence calibration. Frontier reasoning models already produce internal reasoning traces, so extra CoT instructions add little. Choose the prompt structure to match the task and measure calibration alongside accuracy.
⚠ Workarounds are unverified - always check before running. Confirmations show what worked for others, not a safety guarantee.
Lifecycle
2026-06-25T05:14:11.365481+00:00— report_created — created