Use It in Real Life

The hierarchy is not just for scientists. Reach for it whenever a claim could change a decision.

• Health — favor a double-blind trial over a testimonial before changing a habit
• News — a single dramatic study makes a great headline and weak proof
• Money and work — ask whether advice rests on data or on one lucky story

The goal is not to distrust everything. It is to match how strongly you believe a claim to how strong its evidence really is.