Data Scientist → AI Engineer • Training 10
Article-Training • AI Engineering Foundations

Evals

Measuring AI Systems with Evidence

Move from 'this answer looks good' to repeatable evaluation. Build datasets, rubrics, deterministic checks, model-based judges, human review, regression tests and release gates.

Define Success → Build Cases → Score → Compare → Gate → Monitor
🎯 GOAL
→
🧪 CASES
→
📏 METRICS
⚖️ JUDGE
→
✅ GATE
→
📊 MONITOR
8learning modules
24interactive practices
5rapid review questions
50%certificate threshold
Learning target
Design an evaluation system that measures quality consistently before and after deployment.
Practice progress0 / 24

Complete 12 of 24 practices (50%) and enter your name to unlock the Certificate of Participation.

MODULE 01
🎯

Define Success Before Testing

An eval begins with an explicit definition of what good behavior means for the task.

👁️
See it this way

If success is vague, scores become arbitrary.

Core ideas

  • Define task-level acceptance criteria
  • Separate must-have behavior from preferences
  • Include quality, safety and operational goals
Production sketch
criteria = {'correct': True, 'grounded': True, 'format_ok': True}
✅

A score is useful only when it maps to a defined product requirement.

Practice — 3 cases

Practice 1 / Práctica 1
Which principle best matches Define Success Before Testing?
Practice 2 / Práctica 2
Which behavior is the clearest anti-pattern for Define Success Before Testing?
Practice 3 / Práctica 3
What should a production team check for Define Success Before Testing?
MODULE 02
🧪

Build Representative Eval Sets

A useful eval set reflects common requests, edge cases, no-answer cases and known risks.

👁️
See it this way

Testing only happy paths creates false confidence.

Core ideas

  • Sample real task diversity
  • Include edge and failure cases
  • Keep expected outputs or scoring references
Production sketch
eval_set = [common_cases, edge_cases, failure_cases]
✅

The eval set is a product asset and should evolve with the system.

Practice — 3 cases

Practice 4 / Práctica 4
Which principle best matches Build Representative Eval Sets?
Practice 5 / Práctica 5
Which behavior is the clearest anti-pattern for Build Representative Eval Sets?
Practice 6 / Práctica 6
What should a production team check for Build Representative Eval Sets?
MODULE 03
✅

Deterministic Checks

Some requirements can be measured exactly: schema validity, length, allowed values, citations or required fields.

👁️
See it this way

Use code when the rule is objective instead of asking a judge model to guess.

Core ideas

  • Validate JSON/schema
  • Check required fields and allowed values
  • Measure latency and token usage
Production sketch
assert jsonschema.validate(output, schema)
assert latency_ms < 2500
✅

Prefer deterministic evaluation whenever the success condition is deterministic.

Practice — 3 cases

Practice 7 / Práctica 7
Which principle best matches Deterministic Checks?
Practice 8 / Práctica 8
Which behavior is the clearest anti-pattern for Deterministic Checks?
Practice 9 / Práctica 9
What should a production team check for Deterministic Checks?
MODULE 04
⚖️

LLM-as-Judge

Model-based judges can score nuanced outputs such as relevance, completeness or style when a deterministic rule is insufficient.

👁️
See it this way

A judge is another model, not an oracle.

Core ideas

  • Use explicit rubrics
  • Prefer blinded comparisons where possible
  • Calibrate against human labels
Production sketch
score = judge(output, rubric='0-4 relevance')
✅

Judge prompts and rubrics need their own evaluation and versioning.

Practice — 3 cases

Practice 10 / Práctica 10
Which principle best matches LLM-as-Judge?
Practice 11 / Práctica 11
Which behavior is the clearest anti-pattern for LLM-as-Judge?
Practice 12 / Práctica 12
What should a production team check for LLM-as-Judge?
MODULE 05
👥

Human Evaluation

Human review remains important for ambiguous, high-impact or preference-heavy behavior.

👁️
See it this way

Humans are expensive but often define the reference standard for nuanced quality.

Core ideas

  • Use clear reviewer instructions
  • Measure inter-rater agreement
  • Sample high-risk or uncertain cases
Production sketch
review = {'score': 3, 'reason': 'supported and concise'}
✅

Human evaluation is strongest when the rubric is explicit and reviewers are calibrated.

Practice — 3 cases

Practice 13 / Práctica 13
Which principle best matches Human Evaluation?
Practice 14 / Práctica 14
Which behavior is the clearest anti-pattern for Human Evaluation?
Practice 15 / Práctica 15
What should a production team check for Human Evaluation?
MODULE 06
🔁

Regression Testing and Comparisons

Every prompt, model or retrieval change can improve one case and break another. Compare versions on the same eval set.

👁️
See it this way

A single better example does not prove the new version is better overall.

Core ideas

  • Run the same cases across versions
  • Track wins, losses and regressions
  • Keep baselines for comparison
Production sketch
compare(v1, v2, eval_set)
assert regressions < threshold
✅

Treat evals as automated regression tests for probabilistic systems.

Practice — 3 cases

Practice 16 / Práctica 16
Which principle best matches Regression Testing and Comparisons?
Practice 17 / Práctica 17
Which behavior is the clearest anti-pattern for Regression Testing and Comparisons?
Practice 18 / Práctica 18
What should a production team check for Regression Testing and Comparisons?
MODULE 07
🧩

Evaluate RAG and Agents by Layer

Complex AI systems can fail at retrieval, planning, tool use or generation. Layered evals identify the real failure point.

👁️
See it this way

Diagnosing the wrong layer wastes tuning effort.

Core ideas

  • Score retrieval separately from answer quality
  • Score tool selection and tool results
  • Track end-to-end task success
Production sketch
scores = {'retrieval': .9, 'answer': .7, 'task': .6}
✅

Use component metrics plus an end-to-end success metric.

Practice — 3 cases

Practice 19 / Práctica 19
Which principle best matches Evaluate RAG and Agents by Layer?
Practice 20 / Práctica 20
Which behavior is the clearest anti-pattern for Evaluate RAG and Agents by Layer?
Practice 21 / Práctica 21
What should a production team check for Evaluate RAG and Agents by Layer?
MODULE 08
🚦

Release Gates and Production Monitoring

Offline evals should influence deployment decisions and continue as online monitoring signals after release.

👁️
See it this way

Evaluation becomes operational when it can block a bad release and detect drift later.

Core ideas

  • Define minimum release thresholds
  • Monitor live quality proxies
  • Re-run evals after model/data changes
Production sketch
if quality < gate: block_release()
monitor(live_metrics)
✅

Connect eval results to release gates and production observability.

Practice — 3 cases

Practice 22 / Práctica 22
Which principle best matches Release Gates and Production Monitoring?
Practice 23 / Práctica 23
Which behavior is the clearest anti-pattern for Release Gates and Production Monitoring?
Practice 24 / Práctica 24
What should a production team check for Release Gates and Production Monitoring?
5-Question Knowledge Check

Can you measure AI quality systematically?

Open each item after answering it in your own words.

1. What is the key lesson of Define Success Before Testing?

Define explicit, testable success criteria before choosing metrics.

2. What is the key lesson of Build Representative Eval Sets?

Use representative cases that cover normal, edge and failure behavior.

3. What is the key lesson of Deterministic Checks?

Use exact programmatic checks for objective requirements.

4. What is the key lesson of LLM-as-Judge?

Use calibrated rubrics and validate judge agreement with humans.

5. What is the key lesson of Human Evaluation?

Use trained reviewers and explicit rubrics for nuanced or high-impact cases.

Evaluation Blueprint

A reusable production pattern

LayerPurpose
Define Success Before TestingDefine explicit, testable success criteria before choosing metrics.
Build Representative Eval SetsUse representative cases that cover normal, edge and failure behavior.
Deterministic ChecksUse exact programmatic checks for objective requirements.
LLM-as-JudgeUse calibrated rubrics and validate judge agreement with humans.
Human EvaluationUse trained reviewers and explicit rubrics for nuanced or high-impact cases.
Regression Testing and ComparisonsCompare versions on fixed representative cases and track regressions.
Evaluate RAG and Agents by LayerEvaluate components separately and also measure end-to-end task success.
Release Gates and Production MonitoringUse eval thresholds as release gates and monitor post-release drift.

Certificate of Participation

Complete at least 12 of the 24 practice cases (50%) and enter your name.

0 / 24 • 0%
Production note

Evaluation metrics and judge models are imperfect. Calibrate them against human judgment, representative tasks and real failure modes.