The paper disrusses the differences between teaching CAAD by using standard sofware ("off-theshelf"-sofware) and teaching the principles of CAAD ("principles-teaching "). The paper distinguishes four kinds of application for design systems in education: social systems, professiond systems, educational systems, and innovative systems. The paper furthermore proposes to distinguish between computational issues and architectural issues relative to design systems. It appears that there is not a principled distinction between sofware-teaching and principles-teaching when it comes to computational issues of design systems. However, when the architectural content of CAAD systems is concerned, then principles of CAAD systems seem to be more appropriate for teaching. The paper presents work on generic representations as a specific case Generic representations can be used to teach one particular kind of architectural content of design systems. The paper ends with condusions