Large-scale international student assessment studies like TIMSS, PISA, and IGLU have delivered important findings on the cross-sectional distribution of competencies among students attending schools in the Federal Republic of Germany—both in comparison with other nations and as a function of social background and further variables. As valuable as these cross-sectional studies are, they can only be viewed as isolated snapshots documenting a specific point in the life course at a fixed moment in time. To transform such snapshots into a moving picture, the NEPS will be following individuals over time so that we will be able to reconstruct how competencies unfold over the life course, how competencies and decision-making processes relate to various critical transitions in educational careers, along with how and to what extent they are influenced by the family of origin and the structure of teaching and learning processes in Kindergarten, school, vocational training, higher education, and later (working) life. It is also unclear which competencies are decisive for attaining educational qualifications, which for lifelong learning, and which for a successful individual and social life. Therefore, the NEPS will assess important educational processes across the entire life span. This also means that competencies will not just be assessed in Kindergartens or in the general school system, and also not just in vocational training or higher education, but continuously throughout the life course, long after people have left the education system.