Ideal types function as standards with near-zero actual instances.

Evidence

What seems to typify ideal types in practice is that while they do not necessarily differ from ordinary concepts on intension they do differ from them on extension. Typically, when a scholar proposes an ideal type, she is thinking that the extension of the ideal type is likely to be zero or very small: “I shall take it that a distinguishing characteristic of ideal type concepts is that they have no instances” (Papineau 1976, 137). The ideal generally is one that cannot be attained in practice. George W. Bush may aspire to being a man without sin, but he is unlikely to achieve his ideals. This certainly lies behind Weber’s use of the term. Ideal types were useful as a means—really a standard—for thinking about a less-than-ideal reality. — Gary Goertz, Social Science Concepts, 555

Categorization

• DEFINE: Distinguishes ideal types from ordinary concepts by extension rather than intension — ideal types have few or no real-world instances.
• XREF: Connects to Weber’s methodological writings and to measurement theory on unattainable endpoints.