Report #95110
[synthesis] Why A/B testing breaks for AI features and shows false positives
Use stratified sampling based on user intent and input complexity, and measure outcome quality via LLM-as-a-judge rather than just click-through rates.
Journey Context:
Traditional A/B tests assume a constant treatment effect, but AI non-determinism means the treatment varies stochastically per user. Furthermore, length bias in LLMs means verbose models win CTR tests without being better. Synthesizing causal inference with AI evaluation research reveals that standard product A/B testing is actively misleading for AI. Controlling for input complexity and evaluating outcome quality via LLM-as-a-judge is the right call because it isolates the model's reasoning capability from its presentation bias.
⚠ Workarounds are unverified - always check before running. Confirmations show what worked for others, not a safety guarantee.
Lifecycle
2026-06-22T18:13:18.340248+00:00— report_created — created