CS5720 - Week 12
Slide 237 of 240

A/B Testing for ML Models

A/B Testing Fundamentals

A/B Testing for ML models is a controlled experiment where two or more model variants are compared in production to determine which performs better on business metrics, not just offline accuracy.
Why A/B Test Models?

Real-world validation - Test data ≠ Production data
Business impact - Accuracy ≠ Revenue
Risk mitigation - Gradual rollout
User feedback - Behavioral changes
💡 Key Insight
A model with 95% accuracy might perform worse than a 92% accurate model on business metrics like user engagement or revenue!

Testing Strategies

  • 🎲
    Random Split Testing
    Randomly assign users to model A or B
  • 🎯
    Targeted Testing
    Test on specific user segments or features
  • 📈
    Gradual Rollout
    Start with 5%, increase if successful
  • 🔄
    Multi-Armed Bandit
    Dynamically adjust traffic based on performance
  • 🎨
    Feature Flags
    Toggle between models without deployment

A/B Testing Workflow

1
Design Experiment
Define metrics, sample size, duration
2
Implement & Deploy
Set up infrastructure, deploy models
3
Analyze Results
Statistical significance, business impact
Model A (Control)
3.2%
Conversion Rate
$42.50
Average Order Value
89ms
Response Time
Winner!
Model B (Challenger)
3.8%
Conversion Rate
$45.20
Average Order Value
92ms
Response Time
Click on any stage or strategy to learn more about A/B testing implementation!
Prepared by Dr. Gorkem Kar