What is expert vs novice perception?

Expert vs novice perception is a concept in personal epistemology: Experts do not process more information than novices. They process less — because they have learned which information to ignore. Expertise is not faster consumption. It is superior filtration.

Example: Two emergency physicians look at the same ECG strip. The junior resident reads it methodically — rate, rhythm, axis, intervals, segments, morphology — working through a mental checklist of twenty-plus features. It takes her ninety seconds to reach a tentative conclusion. The attending glances at the strip for under three seconds and says: 'Anterior STEMI. Activate the cath lab.' She did not process the strip faster. She processed less of it. Twenty years of pattern exposure taught her exactly which features matter for this class of abnormality and which are irrelevant. The resident sees data. The attending sees signal. They are looking at the same strip, but they are not seeing the same thing.

This concept is part of Phase 7 (Signal vs Noise) in the How to Think curriculum, which builds the epistemic infrastructure for signal vs noise.