Design A/B test for AI chat box

## Context A social platform (e.g., Reddit) plans to launch an **AI chat box** that answers user questions. The functionality overlaps with the existing **Search** experience. ## Task Design an A/B test to evaluate the launch. ### Requirements 1. Define the **primary metric**, **diagnostic metrics**, and **guardrail metrics**. 2. Describe the **experiment design**: - unit of randomization (user/session/etc.) - eligibility and ramp plan - experiment duration and how to handle novelty effects 3. Identify key **product impacts and risks**, including **cannibalization** of Search. 4. List major **confounders / biases** and how you would mitigate them. 5. Specify what decision you would make based on possible outcomes.