Esther Mertens

36 | Chapter 2 To measure bullying, students complete the 2 global items of the Olweus Bully/ VictimQuestionnaire (Solberg & Olweus, 2003). It measures the frequency of bullying and victimization. Additionally, students complete brief sociometric nominations assessing social acceptance, popularity and classmates’ roles concerning bullying. Moderators Students’ gender and ethnicity and trainers’ gender, ethnicity, education, expertise, and degree of received training and supervision are assessed with questionnaires developed for this study. Students’ personality is reported by the student and parent using the Quick Big Five (Goldberg, 1983). It consists of 30 items (i.e., characteristics; e.g., nice, sympathetic, organized) on which the informant can indicate to what extent that characteristic suites the participant. Parental sense of parenting competence is assessed with the subscale Competence of the Parenting Stress Index (PSI; Abidin, 1983) completed by the parent. It measures the degree to which parents feel they are capable enough and have enough skills to cope with their child. The subscale contains 8 items (e.g., “Raising my child is harder than I expected.”). Positive parenting will be measured using the subscales Warmth and Monitoring from the Co-parenting Behavior Questionnaire (CBQ; Schum & Stolberg, 2007) completed by the parent. The subscale Warmth (7 items; e.g., “I spend time doing fun things with my child.”). measures the extent to which parents show parenting behavior tomake their children feel comfortable, accepted and approved. The subscale Monitoring (5 items; e.g., “I knowmy child’s after school activities.”) measures parental awareness of different aspects of the children’s life. Teacher’s sense of competence will be assessed with the subscale Self-efficacy for management of the Teachers’ sense of self-efficacy (Wolters & Daugherty, 2007) completed by the R&W trainer. This subscale measures teachers’ confidence in their skills to effectively manage their classroom. It contains 6 items (e.g., How much can you do to control disruptive behavior in the classroom?”). Mediators Self-control is assessed with the Self-Control Scale short version (Finkenauer, Engels, & Baumeister, 2005) completed by the student. It contains 11 items (e.g., “I wish I had more self-discipline.”). This questionnaire measures students’ ability to change their inner responses, interrupt undesired behavioral impulses and abstain from acting on these tendencies. Additionally, halfway the questionnaire students complete a shortened version (19 items) of a delayed discounting computer task to measure self-