Measuring the big five in self-report and other ratings: A multitrait-multimethod study

The aim of the study is to assess the construct validity of two different measures of the Big Five, matching two "response modes" (phrase-questionnaire and list of adjectives) and two sources of information or raters (self-report and other ratings). Two-hundred subjects, equally divided in males and females, were administered the self-report versions of the Big Five Questionnaire (BFQ) and the Big Five Observer (BFO), a list of bipolar pairs of adjectives (Caprara, Barbaranelli, & Borgogni, 1993, 1994). Every subject was rated by six acquaintances, then aggregated by means of the same instruments used for the self-report, but worded in a third person format. The multitrait-multimethod matrix derived from these measures was then analyzed via Structural Equation Models according to the criteria proposed by Widaman (1985), Marsh (1989), and Bagozzi (1994). In particular, four different models were compared. While the global fit indexes of the models were only moderate, convergent and discriminant validities were clearly supported, and method and error variance were moderate or low.