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Designing Useful AI Evaluations

A layered approach to evaluating retrieval, generation, tool use, cost, and latency.

EvaluationLLMsQuality
DOMAIN
AI Engineering
LEVEL
Advanced
READ
10 min
UPDATED
Aug 25, 2026

MENTAL MODEL / KEY IDEAS

Keep these in mind

  1. 01Start from user failure modes
  2. 02Mix deterministic and judged metrics
  3. 03Inspect slices, not only averages
01

What to evaluate

An end-to-end score hides which stage failed. Useful evaluation separates retrieval, reasoning, tool execution, response quality, and operational constraints.

  • Stage metrics
  • Product outcomes
  • Cost and latency budgets
02

Build the dataset

A compact set of representative and adversarial cases is more useful than a large synthetic dataset with no connection to product behavior.

  • Real examples
  • Known hard cases
  • Clear expected behavior
03

Read the results

Treat evaluation as debugging evidence. Segment results by intent, source, and difficulty before changing the system.