This paper presents the results of a study designed to compare the processes followed by practitioners of three design methods: the algorithm of inventive problem solving, axiomatic design, and environment-based design. Prior literature has postulated the complementary nature of these design methods, and in some cases, has provided case studies of their mutual application on a design problem. However, prior studies have not focused on the detailed activities used in each method to examine the similarities and differences in the outputs of the activities. In this study, a series of three one-day and three three-day design exercises were conducted simultaneously by three international research groups, each focusing on one method. The objectives of this study were to examine the early stages of the design process that deal with macro activities: problem analysis, problem synthesis, and design evaluation and decision making. Several micro design activities were conducted within these, depending on the design method: clarification of requirements, gathering information on existing technologies, initial conceptualization of an assembly of technologies, the identification of system contradictions/coupling, and the solution of contradictions. The objectives of this comparative study were to establish, from observations of practitioners – rather than from a theoretical point of view – the differences and complementarities between the design methods. The problems presented to designers covered a range of design tasks that spanned multiple disciplines, multiple levels of openendedness/specificity of the task, and various levels of inventiveness required. The comparison showed the complementary nature of the design methods, highlighted their respective strengths, and suggested the outlines of an integrated method based on the main benefit of each.