What is schema-driven perception?

Schema-driven perception is a concept in personal epistemology: Your schemas determine what you notice and what you miss.

Example: A radiologist and a first-year medical student look at the same chest X-ray. The radiologist sees a subtle opacity in the left lower lobe and immediately suspects early pneumonia. The student sees a gray image. The X-ray hasn't changed. The photons hitting their retinas are identical. The difference is the schema each person brings to the image. The radiologist's schema for 'normal lung tissue' is so refined that deviations from it pop out automatically — the way a typo pops out to an experienced editor. The student doesn't have that schema yet, so the deviation is invisible. It's not that the student isn't looking hard enough. It's that their perceptual system doesn't know what to look for.

This concept is part of Phase 11 (Schema Foundations) in the How to Think curriculum, which builds the epistemic infrastructure for schema foundations.