Introduction to A/B Testing

Learn how to compare variants and optimize your AI applications with A/B testing in Narev.

LLMs are black boxes. We already know how to optimize black boxes—it's through A/B testing.

A/B testing has been used to optimize everything from social media features at Facebook and LinkedIn, to e-commerce conversion rates, to product pricing strategies, and even political campaigns. It's the proven way to make data-driven decisions when you can't predict outcomes in advance.

The same principle applies to LLMs: compare different configurations on real prompts to see what works best.

How Narev A/B Testing Works

We make it easy to run A/B tests on your AI use cases.

  1. Define your A/B test - The A/B test receives prompts from your system
  2. Create variants - Different model configurations to test (different models, temperatures, prompts, or parameters)
  3. Run experiments - Narev tests all variants against your prompts and measures cost, latency, and quality

Each A/B test can run multiple experiments by creating different variants and tweaking their configurations.

What to test

Variants let you compare:

  • Different models (e.g., GPT-4o Mini vs Claude-3.5 Haiku)
  • Different providers of models (e.g., Claude from Anthropic vs Claude from AWS Bedrock)
  • Different parameters
  • Different system prompts

Narev automatically tracks cost, latency, and quality metrics to show you which variant performs best.