Test more, assume less. Harvard Business School professor Stefan Thomke reveals why leaders should adopt a scientific mindset—and how experimentation drives smarter decisions in an uncertain world. Every day, leaders face high-stakes decisions about products, customers, strategy, and resource allocation. Yet many of these decisions rely on untested assumptions. Overconfidence, gut instinct, and "what worked before" often substitute for evidence, leaving companies exposed to costly missteps. How can leaders navigate today's uncertainty and complexity to make smarter choices? In The Scientific Mindset: How Thinking Scientifically Drives Better Business Decisions , Harvard Business School professor and innovation expert Stefan Thomke offers a compelling solution: adopt a scientific mindset. Drawing on decades of research and using real-world examples, Thomke shows how challenging assumptions, articulating testable hypotheses, and running disciplined experiments transform decision-making. This concise, practical guide introduces a new leadership model grounded in evidence, not just intuition. Through vivid stories—from famous science experiments to companies such as Amazon and Lego reinventing themselves—Thomke demonstrates how experimentation uncovers hidden truths, mitigates risk, and inspires innovation. Readers will learn how to ask deeper questions, design trustworthy experiments, build cultures that value curiosity over certainty, and develop AI systems that ensure reliability while scaling testing. Along the way, Thomke reveals why intellectual humility and a willingness to be proven wrong are hallmarks of great leadership. Adopting a scientific mindset isn't just smart—it's essential for leading effectively today. Whether you're launching a product, rethinking strategy, or making sense of a rapidly changing world, The Scientific Mindset is your road map for making better decisions.