Calculate variance for user retention
Last updated: August 22, 2025
Quick Overview
Given the following scenario about revenue per session, calculate the the p-value.
Uber
August 22, 202518
4
140 solved
Given the following scenario about revenue per session, calculate the the p-value.
Uber asks this during the Onsite to assess your experimentation skills. They want to see how you define success metrics, design controlled experiments, and interpret results with appropriate statistical rigor.
What the Interviewer Expects
- Design a rigorous experiment with proper randomization and sample size calculation
- Define primary and guardrail metrics with clear rationale
- Address novelty effects, network effects, and interference
- Segment results appropriately and identify heterogeneous treatment effects
- Propose follow-up analyses when results are ambiguous
Key Topics to Cover
How to Approach This
- Define success metrics carefully. A good metric is measurable, actionable, and aligned with business goals.
- Run experiments long enough to account for novelty effects and weekly seasonality.
- Use funnel analysis to identify where users drop off for maximum optimization impact.
- Segment results by key dimensions (platform, country, user cohort) to catch hidden patterns.
- Consider network effects and interference between treatment and control groups.
Possible Follow-up Questions
- What would you do if a stakeholder wants to end the experiment early because initial results look good?
- What if you discover a bug in the logging during the experiment?
- How would you handle an experiment where the control and treatment groups are different sizes?
- How would you handle interference between treatment and control?
Sharpen Your Skills on Codemia
Practice similar problems with our interactive workspace, get AI feedback, and track your progress.
Browse Analytics QuestionsSample Answer
Problem Setup
To assess user retention for Uber based on revenue per session, we need to define our analytical question: "Is there a significant difference in user retention before and after implementing a new feat...
Methodology
For this analysis, we will employ a two-sample t-test to compare the means of the control group (users before the feature) and the treatment group (users after the feature). The steps include:
- Rand...
Submit Your Answer
