Esther Mertens

| 39 Study Protocol improves students’ self-control, self-reflection, self-esteem and emotion regulation by performing ANCOVAs. Furthermore, we will analyze whether the change in these concepts mediate the relation between R&W and socio-emotional adjustment and social safety through LGC modeling in M plus . We will model the mediators as well as the outcome measures in this mediation analysis on the assessments before, during, and after R&W (e.g., Deković, Asscher, Manders, Prins, & Van der Laan, 2012). Furthermore, we will study whether R&W decreases deviant communication and increases prosocial communication. We will analyze if changes in deviant and prosocial communication are mediators of the effect of R&W on social safety. We will model these indirect effects in M plus using bootstrapping. Discussion This study protocol presents the design of a study evaluating the effectiveness of R&W in increasing socio-emotional adjustment and social safety in prevocational students. Previous small-scaled research has shown promising results. With this study we try to overcome the limitations of previous studies by incorporating more measurement waves (i.e., prior, during, and after R&W in the first and second year, and at follow-up), and by using a multi-informant (i.e., students, teachers, parents) and multi-method (i.e., questionnaires, computer task, video-observations) approach. We will be in the unique position to not only examine the effectiveness of R&W in different levels of school and parental involvement, but also to study what works for whom, and the working mechanisms of the intervention. A possible threat to the study that we foresee is reaching and engaging the different informants (i.e., students, teachers, parents). In general, we try to reduce this possible threat by organizing focus groups with participating schools. During these meetings we discuss the feasibility of our plans and ask for suggestions (e.g., How can we best reach parents?). In particular, it might be that we ask students too many questions. They could lose their interest and concentration and eventually give answers without reading the questions to finish the questionnaire sooner. We try to diminish this loss of interest and concentration by digitalizing the questionnaire and by adding a computer task halfway the questionnaire. The digital questionnaire enables students to complete the questionnaire on mobile devices which is probably more interesting to the students than filling in the questionnaires on paper. The computer task makes the students feel like they are doing something different than filling in questionnaires, after which they have renewed energy to complete the second half of the questionnaire. Moreover, students can complete the questionnaire during school hours so that it does not cost them additional time. 2