[Evaluation](https://js.langchain.com/docs/concepts/evaluation/): LLM should read this page when needing to understand evaluation methods for LLM applications, searching for tools to assess model performance, or learning how to implement testing frameworks. (This page explains LangChain's evaluation concepts for assessing LLM application performance. It highlights how LangSmith assists with creating datasets, defining metrics, running evaluations, and tracking results over time. The page emphasizes the importance of evaluation for building reliable LLM applications and points to more detailed documentation in LangSmith.)

