A study of the face validity of the 40 item version of the Defense Style Questionnaire (DSQ-40).

There are few studies examining the face validity of the 40-item version of the Defense Style Questionnaire (DSQ-40). Moreover, the existing studies have provided conflicting results. The present study provides an in-depth examination of the face validity of the DSQ-40. Eight clinicians independently attributed each item of the DSQ-40 to a defense mechanism. The defense mechanisms listed in the DSM-IV Defensive Functioning Scale and their definitions were provided as a guide, along with the definition of those defense mechanisms investigated by the DSQ that are not included. It was further specified that the raters could attribute the items to defense mechanisms other than those listed or coping mechanisms. Twelve items out of 40 (30%) were attributed to the defense mechanisms they were supposed to investigate by fewer than four out of the eight raters. This result suggests that a substantial part of the DSQ-40 is lacking in face validity.