- Assistant professor University Heidelberg, Germany, 1964-1972. Professor University Bonn, Germany, 1972, Germany, 1984—2004, University Goettingen, Germany, 1972-1980, University Trier, Germany, 1980-1984.
Author: The Test of Significance in Psychological Research, 1972, Psychology of Learning and Memory, 1977, Imagery and Learning, 1979, Theory and Design of Psychological Experiments, 1980, Imagery and Metacognition, 1992, Learning, Remembering and Forgetting, 1998. Co-editor 4 vols. German Encyclopedia Psychology, 1983.
Co-editor (journal) Methodika.