Maartje Boer

CHAPTER 6 164 Cybervictimization The 10-item Multidimensional Online Peer Victimization Scale was used to assess respondents’ level of online peer victimization (Sumter et al., 2015). Respondents indicated how often in the past six months a peer had ‘Called me names’, ‘Insulted me’, ‘Send me aggressive messages’, ‘Send me nasty messages’, ‘Embarrassed me’, ‘Told my secrets to others so that others do not like me anymore’, ‘Excluded me from something I wanted to participate in’, ‘Did not let me join a conversation or chat while I wanted to’, ‘Purposely acted like I did not exist’, and ‘Did not let me participate in something I wanted to do’ (1 never to 6 about every day ). Cronbach’s alpha varied between 0.89 and 0.91 across all waves. Subjective School Achievements Three items assessed respondents’ subjective school achievements. Respondents were asked ‘How satisfiedwere youwith the grades in yourmost recent school report?’ (1 not satisfied at all to 5 very satisfied ), ‘How many failing grades did you have in your most recent school report?’ (1 none to 5 four or more ), and ‘As compared to most of my classmates, I achieve … school grades’ (1 much worse to 5 much better ). The second item was recoded such that high values indicated high school achievement. Cronbach’s alpha varied between 0.79 and 0.81 in all the waves. Across all waves, adolescents’ mean scores on the three items correlated strongly with their Grade Point Average (GPA)-scores that were obtained from teachers of the participating schools ( r = 0.63 to 0.69, p < 0.001), which suggests that adolescents’ subjective school achievements show high overlap with their objective school achievements. We selected subjective school achievements for this study, as there were relatively many missing values on the GPA-data. Face-to-Face Contact With Friends Respondents reported on their intensity of face-to-face contact with friends using three items on the frequency of peer contact (Baams et al., 2017). Respondents were asked ‘How often do you spend time with friends after school or in the weekends?’, ‘How often are you at your friends’ house?’, and ‘How often do you go out at night or go to a party with friends?’. In order to