Abstract concepts need intermediate theoretical dimensions before they can be measured.

Evidence

When reading about concepts in practice the appropriate structure of the concept is often not clear. It then often becomes a matter of interpreting examples in the text, looking at quantitative measures, and looking at causal hypotheses involving the concept. Nevertheless, it is rare to find a complex or abstract concept that does not implicitly have a three-level structure. Usually the basic level is too abstract and complex to be directly converted into the indicator/data level. The secondary level provides theoretical linkage between the abstract basic level and the concrete indicator/data level. For example, the basic-level concept of “intelligence” usually receives the secondarylevel formulation “verbal ability,” “analytic ability,” or “mathematical ability,” which then allows the actual creation of test questions. — Gary Goertz, Social Science Concepts, 355

Categorization

• DEFINE: Names the three-level concept structure — basic, secondary, indicator — and explains each level’s function.
• XREF: Connects to earlier chapters on concept structure and levels of abstraction in the same book.
• SEED: Essay angle: why every abstract construct (intelligence, democracy, poverty) secretly smuggles a two-step ladder between theory and data.