Your question is Diagnose Novelty in Feature Launch. Take a moment with it on the right.
Talk me through your thinking if you like. When you're confident, submit your answer and I'll grade it like a real screen (7/10 or better passes).
You work on a ride-sharing marketplace product where a newly launched rider app feature shows a strong early lift in engagement after being exposed in an A/B test. The team is excited by the initial results, but you suspect users may simply be reacting to something new rather than adopting behavior that will persist.
How would you analyze whether the observed lift is a novelty effect rather than a durable product improvement? What experiment design and readout would you use to decide whether the feature should ship broadly?