Principlev1
Test category systems with boundary cases that resist clean
Test category systems with boundary cases that resist clean classification, as items at category edges reveal missing dimensions, vague boundaries, and incorrect framing more reliably than central members.
Why This Is a Principle
Derives from Graded Category Membership Structure (categories have graded membership along a spectrum) and Illusion of Explanatory Depth (felt understanding differs from articulated understanding). Boundary cases expose where category boundaries are actually located versus where you think they are, similar to how articulation exposes gaps in understanding.