Is It Possible to Measure the Role of the Bystander and the Victim of Bullying in Children? Construct Validity of Two Brief Pictorial Scales With IRT and CFA Models.

The study's objective was to develop and validate the psychometric properties of two brief pictorial scales to evaluate the roles of bystanders and victims of bullying. A sample of 910 students was considered (49.6%, boys; 50.4%, girls) between the ages of 7 and 13 (M = 10, SD = 1.4). Both instruments present nine pictorial items representing two dimensions: physical bullying (items 1 to 4) and psychological bullying (items 5 to 9). An additional measure of anxiety was used to assess convergent validity. The Confirmatory Factorial Analysis shows that the two-dimensional oblique model, physical bullying and psychological bullying, presents a better fit to the bystander scale data (RMSEA = .040; CFI = .984; SRMR = .033) and in the victim scale (RMSEA = .051; CFI = .978; SRMR = .040) in comparison to other competitor models. From the perspective of the Item Response Theory (IRT), it was found that the items adequately discriminate the levels of the latent variable; therefore, items 1 (physical bullying) and 7 (psychological bullying) are the most accurate on the bystander scale, and items 3 (physical bullying) and 7 (psychological bullying), on the victim scale. It was also found that the degree of difficulty on both scales is lower for the psychological bullying dimension than for the physical bullying dimension. Both instruments demonstrated good psychometric properties; therefore, they can detect school bullying in classrooms.