MISCONCEPTION ALERT!
Validity is about inference, not the test itself. Validity concerns the meaning
of evidence: what we ask students to do, and how we assess the resulting
work. In other words, validity is about our understanding of the results,
not the test itself. We have to be a bit more careful in our talk. Although
everyone casually uses the words “valid” and “invalid” as adjectival modifiers
of “test,” strictly speaking this is inaccurate. Validity is about the
inferences we try to make from particular test results. And sharpening the
power of those inferences is key to becoming a better assessor.