Towards Precedence that Justifies the Knowledge Claims of Design Methods

This paper analyses the relation between the precedence of a design method and the justification of the method. A design method is assumed to advance two knowledge claims concerning its domain of application: that it is an effective means for designing and that it is an efficient means for doing so. It is argued that precedence of a method can justify these knowledge claims under two conditions. The first is that precedence, in addition to descriptions of successful design projects realized with the method, also comprises: (1) negative precedence of unsuccessful design projects; and (2) comparative precedence of design projects carried out with other methods rival to the method concerned. The second condition is that the two knowledge claims of a method can be justified by precedence about only exemplar design tasks that represent the full application domain of the method.