Comparison
Eval-Driven Development vs Online Evaluation
Eval-Driven Development and Online Evaluation are both common AI/LLM terms but cover different ideas. Here is a quick side-by-side.
When you would reach for Eval-Driven Development
As soon as you have more than one prompt change per week or more than one engineer iterating on the same prompt.
A team's prompt PR template requires: eval set updated if behavior changed, baseline win rate ≥ 50%, no regressions on three named cases.
When you would reach for Online Evaluation
After offline eval is solid and you have meaningful production volume. Stretch your eval coverage from a fixed set to a live one.
Phoenix running a faithfulness eval on 5% of production RAG traces, dashboard charts the rolling 7-day mean.
Frequently asked
What is the difference between Eval-Driven Development and Online Evaluation?
Eval-Driven Development: Eval-driven development is the LLM analog of test-driven development: you write evals for behavior before changing the prompt or model, and every change is graded against the same eval suite. Online Evaluation: Online evaluation runs scoring functions over live production traffic — usually a sample of recent traces — to monitor quality continuously instead of relying solely on a fixed offline dataset.
When should I use Eval-Driven Development vs Online Evaluation?
As soon as you have more than one prompt change per week or more than one engineer iterating on the same prompt. After offline eval is solid and you have meaningful production volume. Stretch your eval coverage from a fixed set to a live one.
Are Eval-Driven Development and Online Evaluation the same thing?
No. Eval-Driven Development is evaluation; Online Evaluation is evaluation. They are related but address different parts of the AI stack.