Learning Objectives

After completing your study of this chapter, you should be able to do the following:

• Discuss the concept of a construct, and give examples of theoretical constructs.
• Explain how the current Standards for Educational and Psychological Testing (American Educational Research Association [AERA], American Psychological Association [APA], & National Council on Measurement in Education [NCME], 2014) treatment of con­structs in testing differs from the more traditional usage of the term construct validity.
• Explain and give examples of the three steps of construct explication.
• Explain the process of establishing evidence of validity based on a test’s relationship with other constructs.
• Explain how Campbell and Fiske’s (1959) multitrait–multimethod matrix provides evidence of validity based on a test’s relationship with other constructs.
• Discuss the roles of exploratory and confirmatory factor analysis in establishing validity.

Chapter Summary

Psychologists measure behaviors (activities that are observable and measurable) and constructs (under­lying attitudes or attributes that exist only in our imaginations). Although we cannot observe or measure constructs directly, we can predict behaviors that influence and measure those behaviors.

Because definitions of constructs vary from person to person, psychologists define and explain con­structs carefully. Construct explication is the process of relating a construct to a psychological theory and proposing a nomological network of the constructs and behaviors to which the construct is related.

We gather theoretical evidence of construct validity by proposing the nomological network and exper­imental hypotheses. We then gather psychometric evidence by establishing evidence that the test is reliable and correlates with other tests measuring constructs in the nomological network (convergent evidence of validity) and by confirming that it is not correlated with constructs to which it is theoretically unrelated (discriminant evidence of validity). In addition, evidence of validity based on test content or a test’s rela­tionship with other criterion measures also bolsters the argument that we have strong evidence of validity. Finally, researchers can propose and conduct experiments using the test to measure the construct.

Exploratory factor analysis takes a broad look at test data to determine how many underlying compo­nents are likely. Confirmatory factor analysis is a method that tests theoretical predictions about under­lying variables or factors that make up a construct. Although some constructs are unidimensional or homogeneous, many constructs are multidimensional. The process of confirmatory factor analysis involves proposing underlying factors and then verifying their existence using the statistical procedure of factor analysis.