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A/B Testing

Build Measure Learn

Iterative cycle of hypothesis testing and learning

Build Measure Learn is the core feedback loop of Lean Startup methodology that emphasizes rapid experimentation to validate product hypotheses and reduce uncertainty. This iterative cycle helps teams learn about customers and markets quickly while minimizing wasted effort on unvalidated assumptions. The loop begins with Learn, identifying the riskiest assumptions and formulating testable hypotheses. Build involves creating the minimum viable product or experiment to test the hypothesis. Measure captures data and validates whether the hypothesis was correct. Teams then incorporate learnings and repeat the cycle, iterating toward product-market fit. Key principles include minimizing time through the loop for faster learning, focusing on validated learning over vanity metrics, testing riskiest assumptions first, using minimum viable experiments, making data-driven pivot or persevere decisions, and documenting and sharing learnings across organization. The loop's power lies in speed and focus. Rather than spending months building full features based on assumptions, teams create small experiments, gather real user data, and adapt quickly. This reduces waste, lowers risk, and accelerates finding product-market fit. Common applications include testing new features, validating pricing strategies, exploring market segments, and evaluating business model assumptions.

Learn the Build Measure Learn loop in Lean product development. Discover how rapid experimentation validates ideas and accelerates learning.