This item is only available electronically.The Barratt Impulsiveness Scale (version 11; BIS-11) is a widely used self-report scale of impulsivity. However, many studies have failed to support the three-factor model proposed by the authors of the scale and have instead found a two-factor model in which forward- and reverse-scored items load on separate factors. The two factors have been interpreted as substantive constructs and adopted as alternative scoring schemes in many studies. The present study investigated the factor structure of the BIS-11 and BIS-Brief (an eight-item short form of the BIS-11) in a sample of 232 adults. An exploratory factor analysis (EFA) of the BIS-Brief resulted in a novel two-factor model with a good fit, and this fit was notably improved when the analysis was conducted for women only. A second EFA included BIS-Brief items that were rephrased using linguistic negation and scored in the opposite direction. These items loaded alongside their original counterparts, indicating that the novel factor model is substantive and unrelated to item scoring direction. However, the addition of six simulated careless respondents to the sample resulted in the emergence of a two-factor model reflecting item scoring direction. These results suggest that the BIS-Brief is best described by a novel two-factor model, but this model only applies to women, and it is easily compromised by a small number of careless respondents. Therefore, it is recommended that future research use only the total score of the BIS-Brief.Thesis (B.PsychSc(Hons)) -- University of Adelaide, School of Psychology, 202
