AND-logic shrinks a concept’s extension while OR-logic expands it.

Evidence

Clearly, if we add attributes with AND the extension can only go down (or remain the same in exceptional circumstances). However, if we use OR to add dimensions then the extension almost certainly goes up. — Gary Goertz, Social Science Concepts, 497

Categorization

• DEFINE: Clarifies the mechanism linking logical operator (AND/OR) to the size of the set a concept picks out — Venn intersection vs. union.
• XREF: Connects to the necessary-and-sufficient versus family resemblance distinction (table 2.4) and to Sartori’s logic-based conceptualization.