This study investigated the effectiveness of the KiVa Antibullying Program in two samples of students, one from Grades 1-3 (7-9 years old, N = 6,927) and the other from Grades 7-9 (13-15 years old, N = 16, 503). The Grades 1-3 students were located in 74 schools and Grades 7-9 students in 73 schools that were randomly assigned to intervention and…

Cyberbullying among school-aged children has received increased attention in recent literature. However, no empirical evidence currently exists on whether existing school-based antibullying programs are effective in targeting the unique aspects of cyberbullying. To address this important gap, the present study investigates the unique effects of…

This dissertation is comprised of three manuscripts and presents a line of research aimed at improving the measurement of bullying in schools. The first manuscript investigated the impact of an educational video on self-reports of bullying. A sample of 1,283 middle school students in randomly assigned classrooms either watched or did not watch an…

Associations of peer victimization with adolescent depression and social phobia (SP), while controlling for comorbidity between them, have not been sufficiently explored in earlier research. A total of 3156 Finnish adolescents aged 15-16 years participated in a survey study. Self-reported peer victimization, as well as self-reported depression…