How well the sample can be extrapolated to a population as a whole
Test environment & determines how much it influences behavior
Association of Test with Theory
Test returns similar results with other tests.
Doesn't measure what it isn't meant to measure.
Also known as divergent validity tests.
Campbell and Fiske (1959) introduced the concept of discriminant validity.
On the Face of it, does it looks like what it is supposed to measure
Assess how well a measure is able to provide information to improve program.
Example: When designing a rubric for history one could assess student's knowledge across the discipline.
Sampling from all domains and limit expert biasness.
Focused on the breadth of items item validity focuses on their depth.