Rhetoric as the art of persuasion or effect-oriented communication has been specifically studied from a visual point of view since the 1960s (Schneller 2010a; Joost and Scheuermann 2006, 2008). Bonsiepe (1965) was the first one to use the term “rhetoric” in the context of visual communication. While rhetoric traditionally analyzed and taught the theory and practice of successful speech, the interest now turned to the “rhetorical” means used in visual forms of communication such as posters, book covers, magazine ads, or logotypes in order to catch attention, to surprise or to emotionally affect viewers. At the center of the first attempts to treat visual material in terms of rhetoric was the application of rhetorical figures to the visual. Rhetorical concepts such as metaphor, hyperbole, metonymy, or ellipsis were used to describe and systematize visual techniques in advertising and other forms of commercial graphics (Ibid.; Ehses 1984, 1986, 1995).
In 1985, Buchanan radicalized the idea of a rhetoric of visual objects by completely leaving out the verbal aspects that had previously played a substantial role in sketching the rhetoric of visual communication. His concept of “design argument” puts forward the idea that even industrial design objects such as lamps, bookshelves, or coffee machines incorporate quasi-rhetorical modes of influence. According to Buchanan, the impact on viewers and users is exerted by the technological (logos), characteristic (ethos), or emotional (pathos) features of designed objects. Doubts may be raised about the appropriateness of his application of the term “argument” to design artifacts (Schneller 2010a; Blair 2004), but his concept underlines an important insight, namely that not just the represented content, but also the formal aspects of design are capable of influencing people and can be systematically put to the purpose. The rhetoric of design reaches beyond the semantic levels of persuasion. In the past, visual rhetoric mostly focused on the representational content of images and the possibility of transferring rhetorical figures from text and speech to the visual field. But persuasive means and strategies can be described not only on the level of content (what you say), but also on the level of structure or form (how you say it). In the rhetoric of objects, formal aspects are of utmost importance, whereas semantic features become less important–and are clearly less explicit than in speech. Although it has become popular to talk of “product semantics” or “product semiotics” in industrial design (Krippendorff and Butter 1984; Vihma 1995; Steffen 1997; Krippendorff 2006), the fundamental difference in explicitness must be kept in mind. While there is an explicit content to any normal uttered sentence, the “content” of an armchair or lemon squeezer is of a rather implicit nature. What is more, spoken and written language usually have a linear and temporal structure, which is why rhetorical effects can be created by contrasting, stressing, or repeating linguistic elements over time. The “reading” process of designed objects is guided to a lesser extent than that of a printed text. Designed things mostly generate effects of contrast, stress, or repetition within the spatial arrangement of a formal whole present at one time; graphic design, however, is a special case, since it uses a combination of verbal text, image, and visual form where linear, temporal, and compositional aspects of effects are interwoven. And for time-based visual media such as film and video, the temporal effect dimension is actually as eminent as in speech and text. In any event, effects of content and form can never be strictly separated. The font, size, color, and placement of a written text (which in fact is a design object, too, as is the speed, loudness, and timbre of a spoken text) always have an impact on their overall perception.
Design rhetoric could be defined as the attempt to explain–in terms of the concepts and strategies known from rhetorical theory and practice–how and by which formal means designed things influence us. Although visual effects are probably the most important, a comprehensive understanding of design rhetoric will certainly have to consider other sensory impact levels, that is, the haptic, acoustic, and olfactory effects of designed things; nevertheless, the two research projects presented in this paper focus mainly on the visual rhetoric of designed objects.