the sixteen personality factor questionnaire (16pf) is a self-report personality test developed over several decades of empirical research by raymond b. cattell, maurice tatsuoka and herbert eber. the 16pf provides a measure of normal personality and can also be used by psychologists, and other mental health professionals, as a clinical instrument to help diagnose psychiatric disorders, as well as help with prognosis and therapy planning. the 16pf instrument provides clinicians with a normal-range measurement of anxiety, adjustment, emotional stability and behavioral problems. it can also be used within other areas of psychology, such as career and occupational selection.