1.2 The hierarchy of evidence
Not all SEO "evidence" is created equal. In this module, you'll learn to evaluate claims with a critical eye by understanding the hierarchy of evidence. From simple case studies and before-and-after tests to observational studies and randomized controlled trials. Using real-world examples like the French Paradox, you'll discover why correlation masquerades as causation in SEO, and why most industry advice lacks the rigor to prove actual causation.
Most importantly, you'll see how randomized controlled experiments separate proven results from lucky coincidences, and why that distinction transforms your entire testing program.