Wolfgang Wagner, Dr., is a research scientist at the University of Tuebingen. He studied psychology at the University of Koblenz-Landau, campus Landau. From 2001 to 2008, Wagner had a position there as a research scientist and was involved, inter alia, in the studies German English Student Proficiency International (DESI), and Mathematics Census Rhineland-Palatinate: Competencies, Learning Environment, School Context (MARKUS), and as a project coordinator in the cooperation project Empirical Classroom Research. He received his Ph.D. from the University of Koblenz-Landau in 2008 for his work on methodological problems in the context of students’ perceptions of the learning environment. His main research interests include the assessment of characteristics of learning environments and their effects on the development of academic achievement as well as methodological issues in the field of multilevel structural equation models.