Abstract :
The starting point for teaching transistors must depend on the type of student. For all students, including technicians, who have to study transistors it is desirable that some kind of physical picture, however simple, be given. One way of doing this, based on a two-diode concept of the transistor, is suggested inthe first part of the paper. For the degree or diploma student who will ultimately become a professional radio engineer the author believes that a good background of solid state physics should accompany any instruction on transistors. The education of this type of student in general and the need for an understanding of semiconductors in particular is dealt with in the latter part of the paper.