Most AI research into design has been based on or directed to the electrical circuit domain. This paper presents a mechanical engineer’s view. Design of mechanical parts and products differs from design of electrical circuits in several fundamental ways: materials selection, sensitivity to manufacturing issues, non-modularity, high coupling of form and function, and especially the role of 3-D geometry. These differences, and the role of analysis in mechanical design, are discussed. A model for design is also presented based on the basically iterative nature of the design process. A brief summary of the related research at the University of Massachusetts into application of AI to mechanical design is included.