Concept-generated categories commonly lack clear boundaries

Evidence

Both family resemblance and prototype theories of concepts are crucial because they stress that categories generated by concepts may not have clear boundaries. I believe this to be a ubiquitous problem and I will refer to the “gray zone” to give it a name. — Gary Goertz, Social Science Concepts, 202

Categorization

• DEFINE: Names the ‘gray zone’ — the region where category membership is genuinely indeterminate.
• ADDENDUM: Extends the grafting/trees piece’s interest in how categories get imposed on messy living systems by adding the conceptual-membership version.