This chapter establishes why experimentation is critical for modern architectural practice. It argues that intuition and precedent, while valuable, cannot substitute for empirical evidence when addressing complex design challenges. The chapter differentiates experimental methods from observational research, emphasizing their unique ability to establish causality through controlled manipulation of variables. It highlights how experiments improve decision-making by revealing what design interventions truly work and why. By embedding experimental thinking into architectural workflows, practitioners can validate assumptions, optimize building performance, and produce spaces that enhance human experience. This introduction sets the stage for the book’s focus on rigorous, evidence-based approaches that bridge theory, practice, and innovation.