Common instruments and matching them to the question

Notions clés

Cognitive and achievement batteries

Individually administered intelligence batteries, such as the Wechsler scales, and achievement tests estimate abilities and academic skills against age or grade norms. They are central to questions about intellectual disability, learning disorders and cognitive change, but a composite score rarely settles such a question alone.

Broadband personality inventories

Inventories such as the MMPI-3 and the Personality Assessment Inventory cover many dimensions of personality and psychopathology in one administration and include validity scales for overreporting, underreporting and inconsistent responding.

Brief symptom and severity scales

Scales such as the PHQ-9 rate symptom severity and track change. In its validation, scores of 5, 10, 15 and 20 marked mild, moderate, moderately severe and severe depression, and a score of 10 or more had a sensitivity and specificity of 88 percent for major depression.

Adaptive behavior and informant systems

Adaptive behavior scales, such as the Vineland, measure everyday communication, daily living and social skills from informant interviews or forms. Informant systems such as the ASEBA score parent, teacher and self reports on common scales so the views can be compared.

Validity tests

Performance validity tests check whether ability scores reflect adequate engagement, and symptom validity scales check the accuracy of symptom reports. The 2021 AACN consensus holds that all clinical and forensic evaluations must address the validity of test results.

Exemple commenté

A primary care team begins giving the PHQ-9 at every visit to adults being treated for depression and asks a consulting psychologist how to use the scores.

1. The PHQ-9 rates each of the nine DSM depressive symptoms from 0 (not at all) to 3 (nearly every day), so totals run from 0 to 27.
2. At a first visit, a score of 10 or more is a positive screen; because predictive value depends on how common depression is in the clinic, a positive result is followed by a clinical interview before a diagnosis is recorded.
3. At later visits, the scores track movement across the severity bands at 5, 10, 15 and 20, which is the use its authors intended for guiding treatment decisions.
4. The PHQ-9 does not measure personality, cognition or the causes of the depression, so questions about those call for other instruments.

Use each instrument for the decisions its evidence supports, and add other measures for the questions it was not built to answer.