Context
You work on a consumer app where users see an ETA (estimated time to arrival/delivery) during a funnel (e.g., browsing → checkout → order placed). The team can change product and/or operations to reduce ETA.
You have historical data showing a positive correlation between ETA and conversion (users are more likely to convert when ETA is higher), which seems counterintuitive.
Questions
-
Why might reducing ETA be beneficial?
List plausible business/product benefits and what metrics they would affect.
-
Why might ETA be positively correlated with conversion in observational data?
Provide multiple hypotheses (confounding/selection effects) and how you would test or rule them out.
-
Design an experiment
to estimate the causal impact of reducing ETA on conversion.
-
Define the
treatment
,
control
, and
randomization unit
.
-
Specify
primary metric
,
diagnostic metrics
, and
guardrail metrics
.
-
Discuss risks like interference, seasonality, and delayed effects.
-
Confidence intervals:
Explain how you would compute and interpret a confidence interval for the conversion lift.
-
Unit of analysis:
Why might the analysis
not
be done at the user level? When is user-level appropriate vs session/order/request-level?