Why It Matters
If I measure 'Legitimacy', I can't just ask 'Is it legit?'. I need a rigorous, multi-item scale that stands up to statistical scrutiny.
What To Learn
- Item Response Theory (basics): Understanding item difficulty and discrimination.
- EFA vs CFA: Exploratory (finding the structure) vs Confirmatory (testing the structure).
- Construct Validity: Convergent (relates to similar things) and Discriminant (distinct from different things).