In this case, the psychologist is trying to establish "construct validity" of the measure.
Construct validity is "how much a test estimates what it claims, or implies, to quantify.
There are various distinctive estimates that can be utilized to approve tests, one of which is build legitimacy. Build legitimacy is utilized to decide how well a test estimates what it should quantify. As it were, is the test built in a way that it effectively tests what it professes to test? Construct validity is normally confirmed by contrasting the test with different tests that measure comparable characteristics to perceive how exceptionally associated the two measures are.