Design an A/B test for a search ranking change

Last updated: September 4, 2025

Quick Overview

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

Pinterest
Analytics & Experimentation
Data Scientist
Pinterest
September 4, 2025
Data Scientist
Take-home Project
Analytics & Experimentation
Easy

83

11

3,970 solved


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

This analytics question from Pinterest's Take-home Project tests your ability to think critically about data. The interviewer expects you to consider confounding variables, selection bias, and the difference between correlation and causation.

What the Interviewer Expects
  • Define clear success metrics aligned with business goals
  • Propose a basic experimental design with control and treatment groups
  • Interpret results correctly and draw reasonable conclusions
  • Identify obvious confounding variables
Key Topics to Cover
A/B testing methodology
Guardrail metrics
Long-term vs short-term metrics
Segmentation and heterogeneous effects
Sample size and power calculation
Metric definition and success criteria
How to Approach This
  1. Define success metrics carefully. A good metric is measurable, actionable, and aligned with business goals.
  2. Run experiments long enough to account for novelty effects and weekly seasonality.
  3. Use funnel analysis to identify where users drop off for maximum optimization impact.
  4. Segment results by key dimensions (platform, country, user cohort) to catch hidden patterns.
  5. 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 interference between treatment and control?
  • What if you discover a bug in the logging during the experiment?
  • What would you do if a stakeholder wants to end the experiment early because initial results look good?
Sharpen Your Skills on Codemia

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

Browse Analytics Questions
Sample Answer
Defining the Analysis Framework

Start by framing the problem clearly: 1. **What question are we answering?** Be specific about the hypothesis or business question. 2. **What data d...

Analysis Approach

**Exploratory Analysis**: Start with aggregate trends, then segment by key dimensions (platform, country, user cohort, channel). Look for heterogeneou...


Submit Your Answer
Markdown supported

Related Questions