Design an A/B test for a new checkout flow

Last updated: March 10, 2026

Quick Overview

Design an experiment to test the impact of a redesigned homepage. Include sample size calculation, metrics, and analysis plan.

HRT
Statistics & Math
Data Scientist
HRT
March 10, 2026
Data Scientist
Technical Screen
Statistics & Math
Medium

32

6

3,766 solved


Design an experiment to test the impact of a redesigned homepage. Include sample size calculation, metrics, and analysis plan.

This statistics question from HRT'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
  • Set up the problem formally with proper notation
  • Apply the correct statistical test with clear justification
  • Interpret results with appropriate caveats and confidence levels
  • Discuss practical significance vs statistical significance
  • Identify potential confounders and how to address them
Key Topics to Cover
Probability distributions
Multiple testing correction (Bonferroni, FDR)
Regression analysis
Hypothesis testing (H0, H1, p-values)
Causal inference basics
How to Approach This
  1. Define your hypotheses (H0 and H1) clearly before performing any test.
  2. Calculate required sample size BEFORE running an experiment, using power analysis.
  3. Remember the Central Limit Theorem: sample means become approximately normal with large n.
  4. Watch for Simpson's paradox. Always segment data by key dimensions.
  5. Distinguish between statistical significance and practical significance.
Possible Follow-up Questions
  • What alternative statistical method could you use here?
  • How would you handle multiple comparisons?
  • What if the sample size is very small?
  • How would you explain this result to a non-technical audience?
Sharpen Your Skills on Codemia

Practice similar problems with our interactive workspace, get AI feedback, and track your progress.

Browse Statistics Questions
Sample Answer
Setting Up the Problem

Start by formalizing the problem: 1. **Define the hypotheses**: H0 (null hypothesis) and H1 (alternative). Be precise about what you're testing. 2. ...

Solution Approach

**Compute the test statistic**: Apply the appropriate formula using the sample data. **Find the p-value**: The probability of observing a result this...


Submit Your Answer
Markdown supported

Related Questions