Calculate Sample Size for Effective A/B Test Design
Company: Walmart Labs
Role: Data Scientist
Category: Analytics & Experimentation
Difficulty: medium
Interview Round: Onsite
##### Scenario
Designing an A/B test for a marketing feature rollout.
##### Question
How do you calculate the required sample size for an A/B test?
What techniques can improve the statistical power of the experiment?
##### Hints
Use power analysis (effect size, alpha, beta); improve power with variance reduction, stratification, larger samples, longer tests.
Quick Answer: This question evaluates a candidate's competency in experiment design, sample size calculation, and statistical power analysis for binary conversion metrics within the Analytics & Experimentation domain.