Validity measures the usefulness of a test for specific purposes. For instance, tests of depression, such as the Beck Depression Inventory (BDI), correlate well with clinician assessments of depression, so they can be considered valid measures of depression. On the other hand, the BDI does not predict job performance well, so it would be invalid for that purpose.
Types of validity include criterion-related, content, face, and construct validity. Criterion-related validity looks at the correlation between tests scores and a criterion that the test scores could be expected to predict. For instance, SAT scores for high school seniors could be expected to correlate with their first-year college GPA. Content validity generally depends on expert opinion and looks at whether the test adequately samples the content of interest. A math test for high school students should sample the types of math problems that are found in high school math textbooks and should cover the domains that high school math teachers say are important. Face validity is important, but is not validity in the technical sense. A test has face validity if it appears to measure what it purportedly measures. For instance, a math test for truck drivers should ask questions about gas mileage and load weight. If it contained questions about cake recipe proportions, it would lack face validity. Construct validity is usually accumulated over time and represents the accumulation of many validity studies. It indicates whether the test appropriately measures a theoretical construct.
For this Discussion, you concentrate on construct validity. To prepare, choose a construct to use (one that was not used in the examples), and consider how you might assess the construct validity of a measure of that construct. Then think about how the reliability of your measure might influence its validity.
With these thoughts in mind:
Post by Day 4 a description of the construct you selected. Then explain how you might assess the construct validity of a measure of that construct. Finally, explain the influence of reliability of your measure on the magnitude of its validity. Support your response using the Learning Resources and the current literature.
