Construct validity concerns whether evidence can show that what the instrument is measuring is at all what the offered theory claims it is (whether each construct in the model "adequately represents what is intended by theoretical account of the construct being measured").

Questionnaires may be generic (designed to be used in any disease population and cover a broad aspect of the construct measured) or condition-targeted (developed specifically to measure those aspects of outcome that are of importance for a people with a particular medical condition).

This suggests a distinction between the construct measured by these assessments, as one is ability-based and the other is skill-based.

One formal definition is that it is "a summary of the evidence contained in an examinee's responses to the items of a test that are related to the construct or constructs being measured."

A small item-correlation provides empirical evidence that the item is not measuring the same construct measured by the other items included.

Phrase completion scales - Respondents are asked to complete a phrase on an 11-point response scale in which 0 represents the absence of the theoretical construct and 10 represents the theorized maximum amount of the construct being measured.

Evaluation of discriminant (divergent) validity - The construct being measured by a test should not correlate highly with different constructs.

Given the social nature of the interview, applicant responses to interview questions and interviewer evaluations of those responses are sometimes influenced by constructs beyond those the questions were intended to assess, making it extremely difficult to tease out the specific constructs measured during the interview.

The initial items were written so that the content would be directly relevant to the different constructs measured by the test.

All of the constructs measured by the PAI are commonly used by psychologists and are named in such a way that they can be readily understood.