The validity of MMPI subtle and obvious items in psychiatric patients.

This study was designed to assess the validity of four clinical scales with and without subtle items; and the relative validity of obvious and subtle items. Criteria were questionnaire, mental status, diagnostic, and drug treatment measures; subjects were 73 psychiatric inpatients. Across criteria, the results indicated that the validity of the full scales was not improved by the removal of subtle items; and with the exception of the PD scale, subtle items generally were found to be of similar convergent validity and possibly superior discriminant validity. These findings have implications for psychometric theory and test construction strategies.