What is an A/B test?

• A. An online test comparing three or more variants
• B. A qualitative study of user feedback
• C. An online test comparing two variants to determine which performs better, usually based on clicks
• D. A systematic audit of ad spend

Answer: (C)

A/B testing is a controlled experiment that compares two variants shown to users at random to see which performs better on a chosen metric, such as clicks or conversions. The goal is to determine, under the same conditions, which version delivers the superior outcome with statistical confidence, so decisions are data-driven rather than guesswork. This approach focuses on a direct, side-by-side comparison of two options, distinguishing it from qualitative studies that gather opinions without measuring performance, and from ad spend audits that review expenditures rather than test outcomes. It also differs from tests with more than two variants, which would be a multivariate or multi-variant experiment rather than a traditional A/B test.