Resumen
Two important challenges in research on bullying are to have reliable tools to measure traditional bullying and discriminatory bullying related to special educational needs (SEN), and to learn more about their prevalence. We present the validations of two instruments to measure bullying (European Bullying Intervention Project Questionnaire, EBIPQ) and discriminatory bullying with respect to SEN (EBIPQ–Special Education Needs Discrimination version, henceforth EBIPQ-SEND). A total of 17,309 teenagers from Ecuador took part in the study (M = 14.76, SD = 1.65; 49.9% male). The item response theory analyses evidenced accuracy and quality of the measures. The confirmatory factor analyses of the EBIPQ and the EBIPQ-SEND revealed the same two-factor structure—aggression and victimization—regardless of gender, showing optimal fit indexes. We present the results of the prevalence according to the roles of participation in traditional bullying and discriminatory bullying around SEN. Significant gender and age differences were observed for involvement in both phenomena. We also discuss the advantages of applying the EBIPQ and the EBIPQ-SEND to evaluate and diagnose harassment and discriminatory harassment around SEN.