Your geo test shows +5% but you only have 20 markets — is it real? — Pinterest Marketing Data Science Data Scientist Interview

Your geo test shows +5% but you only have 20 markets — is it real?

Decide from resultsHard

Problem. A geo-holdout suggests a marketing channel lifted revenue +5%, but you only have 20 markets and the market-level data is noisy. Do you believe it, and how do you decide?

Before you reveal: say your answer out loud, as if you were in the real interview — get your reasoning across clearly first. There is no single correct answer: reading what the interviewer is really after and defending your own thinking is what makes an answer strong.