Kepler's laws of planetary motion
Kuhn introduced the concept of an exemplar in a postscript to the second edition of "The Structure of Scientific Revolutions" (1970). He noted that he was substituting the term 'exemplars' for 'paradigm', meaning the problems and solutions that students of a subject learn from the beginning of their education. For example, physicists might have as exemplars the inclined plane, Kepler's laws of planetary motion, or instruments like the calorimeter.