This measure is a brief self-report questionnaire intended to support differential screening of vocational interests and preferences. The Differential Diagnostic Questionnaire presents paired, forced-choice statements to elicit an individual’s relative orientation toward broad occupational domains.
It consists of 20 items and typically takes about 15 minutes to complete. Item content is designed to differentiate preferences across five categories (e.g., nature-focused, technical, interpersonal, symbolic/information-oriented, and artistic domains), which may be used to inform career counseling or exploratory assessment. The Differential Diagnostic Questionnaire is attributed to Robert L. Spitzer and Janet B. W. Williams.