Compare Two Rare-Event Rates with Different Exposure
WaymoData Scientist · Technical Screen
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Compare sparse event rates across unequal mileage using a two-sample Poisson framework, exact conditional testing, and honest uncertainty.
Compare Two Rare-Event Rates with Different Exposure
Two versions were observed over different amounts of mileage, and each produced only a small number of events. Can you treat the estimated event rate of one version as a known value when computing a p-value for the other? Explain how you would compare the rates and report uncertainty. No event counts or mileages are supplied.
Hints
Hint 1
Condition on the total number of events: Under a shared-rate null, ask how the total events should be allocated between two different exposure amounts.
Follow-up questions
- What if one version has zero observed events?
- How would different mixes of operating conditions affect the comparison?
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