For some teachers it may be hard to believe that 3D-CAD has now been taught in secondary schools for more than twenty years. My own experience dates back to around 1984 with the introduction of the British architectural package ‘Scribe’ into schools in Canberra, Australia. Despite a brief, and totally unsatisfying, foray into 2D-CAD in the late 1980’s I have been teaching 3DCAD to students, undergraduate Design and Technology teachers and teachers ever since. In late 2001 I somewhat recklessly volunteered to coordinate ProDesktop training throughout Australia on behalf of the Industrial Technology and Design Teacher’s Association and am now in the early stages of working out how to introduce ProEngineer. I mention these facts in order to provide a context for an admission that for the majority of this time I taught 3D-CAD in the manner I was taught. That is, teaching how to use 3D-CAD through a process of learning algorithms – this is how to extrude, this is how to revolve etc. However, over the last few years I have begun to question the effectiveness of this pedagogy.