What is classification errors?

Classification errors is a concept in personal epistemology: Putting something in the wrong category means the wrong actions get applied to it.

Example: A hospital classifies a patient's chest pain as acid reflux instead of a cardiac event. The patient gets antacids instead of an angiogram. The treatment protocol was executed perfectly — but against the wrong category. The error wasn't in the treatment. It was in the sorting. Every downstream action inherited the original misclassification.

This concept is part of Phase 12 (Classification and Typing) in the How to Think curriculum, which builds the epistemic infrastructure for classification and typing.