Substitutability forms the underlying continuum spanning AND and OR concept structures.

Evidence

One can contrast the family resemblance with the necessary and sufficient condition concept structures, with one as the positive pole and the other as the negative pole of a concept structure continuum. I have frequently contrasted the AND of the necessary and sufficient condition structure with the OR of family resemblance concepts. At the same time one needs to theorize the continuum lying between the two poles. It is substitutability that forms the underlying continuum between AND and OR. — Gary Goertz, Social Science Concepts, 847

Categorization

• XREF: Connects to the book’s earlier chapters 2 and 3, which established family resemblance and necessary-and-sufficient structures as the two poles.
• DEFINE: Defines substitutability as the continuum underlying the difference between AND and OR aggregation rules, grounding later measurement choices.