CAD (Computer Aided Design) has now become an integral part of Technology Education. The recent introduction of highly sophisticated, low-cost CAD software and CAM hardware capable of running on desktop computers has accelerated this trend. There is now quite widespread introduction of solid modeling CAD software into secondary schools but how much is really known about the processes of learning and teaching CAD, particularly solid modeling? This paper will discuss current practice in CAD teaching and the way this relates to solid modeling. It will discuss the findings of current research with particular emphasis on the difference between command knowledge and strategic knowledge and how this relates to the development of CAD expertise. "Command knowledge" is referred to as knowledge of the commands (algorithms or tools) and the procedures to use those tools within CAD software while "strategic knowledge" is concerned with knowledge of the alternate methods by which a specific task may be achieved and the process by which a choice may be made. The results of a recent experimental study into the teaching of CAD expertise will then be outlined and the implications for the teaching and learning process will be discussed.