Interpret mixed results across segments from an experiment
Last updated: June 11, 2026
Quick Overview
An experiment shows conflicting results. What conclusions can you draw? What are the caveats?
Doordash
June 11, 202629
6
852 solved
An experiment shows conflicting results. What conclusions can you draw? What are the caveats?
Doordash 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 if the experiment shows a positive short-term effect but you suspect a negative long-term impact?
- How would you handle seasonality in your experiment?
- How would you handle an experiment where the control and treatment groups are different sizes?
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Browse Analytics QuestionsSample Answer
Problem Setup
The analytical question we need to address is: "Why are the results from our recent experiment across different segments showing conflicting outcomes?" To investigate this, we first need to gather dat...
Methodology
For this analysis, we will employ a combination of hypothesis testing and regression analysis to identify any heterogeneous treatment effects across segments. Specifically, we'll use ANOVA to test for...
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