Design an A/B test for a new checkout flow
Last updated: January 11, 2026
Quick Overview
Design an experiment to test the impact of a redesigned homepage. Include sample size calculation, metrics, and analysis plan.
Goldman Sachs
January 11, 2026143
13
3,759 solved
Design an experiment to test the impact of a redesigned homepage. Include sample size calculation, metrics, and analysis plan.
This statistics question from Goldman Sachs's Technical Screen tests your ability to apply mathematical reasoning to practical problems. The interviewer expects precise definitions, correct methodology, and awareness of assumptions and limitations.
What the Interviewer Expects
- State the correct formula or theorem with clear definitions
- Apply the concept to the given scenario step by step
- Interpret the result in plain language
- Identify assumptions and when they might be violated
Key Topics to Cover
How to Approach This
- Define your hypotheses (H0 and H1) clearly before performing any test.
- Calculate required sample size BEFORE running an experiment, using power analysis.
- Remember the Central Limit Theorem: sample means become approximately normal with large n.
- Watch for Simpson's paradox. Always segment data by key dimensions.
- Distinguish between statistical significance and practical significance.
Possible Follow-up Questions
- What assumptions does this test make, and how would you validate them?
- What alternative statistical method could you use here?
- How would you design a follow-up experiment based on these results?
- How would you handle multiple comparisons?
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Browse Statistics QuestionsSample Answer
Problem Formulation
To evaluate the impact of a redesigned homepage on user engagement during the checkout process, we will conduct an A/B test. Let:
- Group A represent users who see the current homepage (control group)...
Solution Approach
- Sample Size Calculation:
- We need to determine the sample size required for our A/B test to achieve sufficient power, typically 80%.
- Using the formula for sample size for comparing tw...
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