Katrin Bölsterli Bardy develops, in the first of three sub-studies, empirically based standards for competency-oriented science textbooks for the first time. These standards form the competency-oriented textbook framework (KOS), which serves for textbook analysis as well as for the development of new competency-oriented teaching materials. In the second study, the author examines the different demands placed on a competency-oriented textbook based on the profession. In the third study, she analyzes further influencing factors on the demands for a competency-oriented textbook, including the influence of teaching/learning understanding and attitudes towards competency orientation.