Crystal Smit

Chapter 5 100 The Share H 2 O Social Network Intervention Briefly, the social network intervention comprised of (1) identifying and selecting the influence agents and (2) training the influence agents, followed by an informal follow-up a week later. The influence agents were identified through peer nominations. Children nominated the peers on four sociometric nomination questions (“Whom do you ask for advice?”; “Who in your classroom are leaders or take the lead often?”; “Whom do you want to be like?”; and “With whom do you talk about what you drink?”; Starkey et al., 2009). The selection criteria for the influence agents were those from each participating classroom who were most often nominated by their peers on all items combined. To ensure gender balance in relation to the composition of the classrooms, 15% of the boys and 15% of the girls with the most nominations were selected as influence agents. This resulted in an average of five children (range 3–6 children; SD = 1.06) per participating classroom being trained as influence agents (Smit et al., 2020). The influence agents’ training lasted 1 hour and took place at school, led by research assistants who worked in pairs. The research assistants were trained ( ≈ 8 h) by skilled researchers who had ample expertise in conducting research with children at schools and with an autonomy-supportive approach to working with children. The research assistants all had a background in pedagogical sciences, in which they studied the development of children and adolescents. To ensure that each training session in the intervention classroom was conducted in a similar fashion, the principal trainer accompanied each research assistant on their first training session and provided them with a guideline to facilitate the delivery of the training. This guideline contained information about Share H 2 O in general, the theoretical principles of the intervention approach and training, and a detailed script to implement each technique in the training. In addition, the research assistants were in constant contact with the principal trainer, and interim evaluations were performed after each training was given. As described above, the Share H 2 O training was grounded in self-determination theory and refined with input from children and research experts, and thereafter