DiAnn wasn’t too surprised to see Edgar arrive shortly after her office hours began. The material recently presented by the instructor in the psychological testing course for which she served as the graduate teaching assistant was challenging for many of the students in the class. “How can I help you, Edgar?” she inquired. Edgar, his usual affable persona replaced by a serious tone, replied, “I can’t get this topic of validity. I knew I’d better come in and see you after I threw the textbook down in frustration.” 

“Wow, I’m glad you did. What seems to be the trouble?” DiAnn asked.

“Well, in class I thought I understood the definition of validity. Validity refers to whether the test measures what it purports to measure. Fine. But after class the more I read the textbook’s explanation of validity, the more I got confused.” 

Interrupting, DiAnn asked, “How so?” 

Edgar was ready. “I was reading about content validity, criterionrelated validity, and construct validity. Are these all related? Or are they different? Initially, as I was reading, there seemed to be three distinct types of validity. But then it seemed that I couldn’t tell the difference among the three.”

DiAnn smiled. “Perhaps you are smarter than you give yourself credit for Edgar. In many ways, you are correct.” As DiAnn explained what she meant by her rather cryptic initial response, Edgar began to feel more and more comfortable with the material. 

Questions 

1. In what ways does “content validity” provide evidence of the meaningfulness of test scores?

2. In what ways does “criterion-related validity” provide evidence of the meaningfulness of test scores?

3. Is Edgar’s concern over not being able to distinguish among the various validation strategies warranted? Explain.

4. Explain why the trinitarian view of validity (content, criterionrelated, construct) indicates an insufficient view of validation.

5. Explain how Messick’s (1995a) aspects of construct validation incorporate each of the following “outdated” terms under the umbrella of construct validity:

a. Content validity

b. Criterion-related validity

c. Convergent and discriminant validity.