Rhetoric is commonly understood as the art of persuasion or effect-oriented communication. Since the 1960s, there have been various attempts to extend rhetoric from speech to visual communication and to design in general. Design rhetoric addresses the effects of artifacts and especially the techniques by which they can be generated and controlled in the design process. The central problems of this approach are the identification of effects and the validation of rules linking design aspects to specific effects. The goal of this article is to demonstrate how these problems can be dealt with by means of a triangulation of analysis, expert judgments, practice-based research, and laboratory experiments. The suggestions made are based on the results and methods developed over the course of two Bern University of the Arts research projects on visual rhetoric in commercial graphics and public-transport information design. While advertising and mass communication theory as well as the psychology and sociology of media are generally more interested in the macrostructural and postcommunicative effects of their objects of investigation (that is, how they affect actions, purchase decisions, quality of life, social structures, or mental equilibrium of users and receivers), the design-theoretical approach presented here is concerned with the micro-structural impact levels: the immediately detectable effects resulting from the formal composition of designed objects, effects that are grounded in the appearance, and sometimes even in the intrinsic properties of things (that is, what kind of primary impression they make on the viewer). In the first two sections, a short introduction to design rhetoric is provided–particularly for readers not yet familiar with the topic–and the main focus and hypotheses of the approach are presented. In the remaining sections, the methods of ascribing effects to design artifacts applied in the two projects are outlined and the arising difficulties and possible ways of overcoming these difficulties are discussed.