zero-shot-cot-trigger-phrase

Summary

Adding the short phrase "Let's think step by step" to a prompt causes a large language model to walk through intermediate reasoning steps before giving an answer, even without being shown any examples of how to do so. This matters because it gives the system a zero-cost, zero-data way to improve reasoning quality, and it rests on a well-cited peer-reviewed demonstration (Kojima et al., NeurIPS 2022) rather than anecdotal evidence.