This paper describes how a staged approach to the development of students? abilities to engineer software systems applies to the specific issue of teaching software design. It evaluates the courses relating to software design in the Software Engineering volume of Computing Curriculum 2001 with a theoretical model that has been developed from a well-established programme in software engineering, from the perspectives of how well the courses support the progressive development of both students? knowledge of software design and their ability to design software systems. This evaluation identifies some topics that would be better taught earlier than recommended, and others that should be deferred until later in the curriculum.