This article introduces the National Educational Panel Study (NEPS). This German longitudinal study produces a vast amount of data for the scientific community, and researchers all around Europe are invited to use the data to address various research questions empirically. Therefore, the authors provide information about the purpose as well as the design of this educational study that has just released data from several starting cohorts, ranging from newborns to adults. As the authors have coordinated the starting cohort of students in lower-secondary school, this target group will be introduced in more detail, with the implementation of NEPS's design being outlined, as well as the tests and survey contents. The analytical potentials are exemplified by the authors' stage-specific research on German-language instruction, the development of orthography competence, and engagement in reading and orthography in lower-secondary school. An overview of different modes of access to the available data completes this research report.

This chapter introduces the scope and the research program of stage 4 of the German National Educational Panel Study. Stage 4 follows the target persons through secondary education up to their transitions to higher secondary education, vocational education and training, or direct entry into the labor market. From a life-course perspective, this stage allows us to monitor individuals’ educational trajectories in lower secondary education as results of a dynamic interdependence of educational decision-making, different learning environments, and competence development while also paying attention to the educational careers of migrants and returns to education. Following a general introduction, this chapter gives an overview of the general survey program of stage 4 regarding the tests and questionnaires administered to students as well as the questionnaires and interviews administered to their teachers, principals, and parents. Thereafter, the specific research focus of stage 4 on the interrelated development of reading and orthography as well as on the cognitions, attitudes, and behaviors related to these two competencies is outlined. With regard to orthography, stage-specific tests are applied to assess the students’ competency trajectories in this crucial domain. With regard to reading, stage 4 focuses on the development of the students’ reading engagement. A third key aspect of the stage-specific research introduced in this chapter is the quality of instruction.