Evaluating products or treatments without revealing their identity to the tester, the gold standard for honest assessment. In sensory science, blind tasting strips away brand, price, and packaging influences, revealing what people actually prefer when only flavor counts; countless premium products have stumbled in blind tests against cheaper rivals. In supplement and drug trials, double-blind designs, where neither subject nor researcher knows who received what, eliminate expectation effects that otherwise inflate apparent efficacy. The method’s power is its humility: it assumes everyone, including experts, is suggestible, and structures the test to defeat that suggestibility. From wine competitions to clinical trials, blinding is how we find out what is true rather than what we wish were true.