Final answer:
Discriminant validity refers to the extent to which a measure is not strongly correlated with unrelated constructs, ensuring that the tool accurately assesses the targeted concept.
Step-by-step explanation:
A good summary of discriminant validity is that measures of two unrelated constructs should not correlate strongly. Discriminant validity is about ensuring that a test does not closely relate to variables with which it shouldn't theoretically have an association. It is a component of construct validity that is focused on whether a measurement tool measures the construct it's intended to measure.
For example, if you were measuring academic ability with a test, you would expect it to have a low correlation with unrelated constructs like physical endurance. Hence, discriminant validity ensures that when instruments are used for psychological research, they measure constructs in a way that is not conflated with other variables that are not of interest in that particular study.