The PISA-2000 study revealed that German Secondary-School students – in international comparison – showed only an average performance. This led to an intensive nationwide educational policy discussion about measures to improve the school system and much debate centred on whether switching to all-day schooling. As is the case in other middle European countries, the majority of German schools are Half-Day-Schools: a typical school-day ends between noon and 2 pm. The unfavourable results of the PISA 2000 study provided an impulse for a nationwide “All-Day-School movement” supported by major financial and other investments to establish All-Day-School programs. As a consequence, the percentage of All-Day-Schools increased considerably: Today approximately one third of all German schools provide all-day curricula for their students and this quota is continuously rising. This paper examines the effects of All-Day-School programs on the students´ school enjoyment. The conjecture that positively and negatively evaluated school experiences that a student undergoes during his or her school time have a corresponding effect on school enjoyment is quite straight-forward (e.g. Fend 2001). The “Mediation Effect Model for School Enjoyment” (MEMSE, Rollett 2007) supplements this plain causal dependency. The theoretical model assumes that the quality of the socio-emotional relation perceived by the students towards teachers and other educational staff constitutes an important mediating variable for channelling school experience-based effects on overall school enjoyment. It is conceptualised as a filter, generally linking variables addressing pedagogical school features to students´ emotional reactions to school experiences.

The MEMSE is tested by using the data of the first two waves of the longitudinal “Study on the Development of All-Day-Schools” (StEG, http://www.projekt-steg.de, Holtappels, Klieme, Rauschenbach & Stecher 2007) including a representative sample of 373 German Primary- and Secondary-Schools. At each stage of the survey (2005, 2007 and 2009) heads, teachers, all-day staff, parents and students are extensively assessed employing standardized questionnaires. The general assumptions of the MEMSE are investigated by using a multi-level path-analytic approach based on the first wave data from 273 Secondary-Schools. 14.895 students (5th to 9th grade) provided information about their all-day activities (Indicators: “school subject-oriented activities”, “interdisciplinary activities” not focusing on school subjects and “leisure time activities”), how they judged the quality of the socio-emotional relation towards the educational staff and reported to which extent they enjoy school. In a subsequent analysis, second wave retest variables were introduced to evaluate the model.

Both the findings of the cross-sectional and longitudinal analyses provide empirical evidence for the validity of the assumptions central to the Mediation Effect Model for School Enjoyment. The causal chain revealed can be briefly described as follows: The kind of all-day activities a student attends (and a school provides) has an impact on his or her evaluation of the All-Day-School program. A positive evaluation of the students´ individual All-Day-School experiences (indicators: “learning utility” and “social utility”, Radisch, Stecher, Klieme & Kühnbach, 2007) fosters the relatedness student’s sense towards all-day staff, which in turn has a positive effect on the students´ overall school enjoyment. These results illustrate and emphasise the importance of the quality of the social-emotional interaction and the resulting relations between students and the professionals responsible for them during school time.