Gray zone concepts require first fixing the boundaries on either side.

Evidence

The first step then in conceptualizing the gray zone is establishing the boundaries on either side. Gray zone concepts are likely to have two necessary conditions: (1) not–positive pole and (2) not–negative pole. This says nothing in particular about how the positive or negative poles are conceptualized; they could be both done via family resemblance. The key point is that not being at the poles are necessary conditions for the gray zone. — Gary Goertz, Social Science Concepts and Measurement, 1122

Categorization

• SEED: Angle: why definitional-by-exclusion silently smuggles in whatever you excluded — the downstream cost of negational categories in policy and social science.