What is visual literacy?
Since the Vidtionary project suggests by its very name an interface between the realm of the visual and language, it seemed natural that I would find much relevant material in the literature surrounding the emerging concept of visual literacy. I soon realized that visual literacy is a concept used loosely in various disciplines. Thus, it cannot be said that there is a well-established concept of visual literacy at all. James Elkins (2003) has written:

The first thing that needs to be said about visual literacy is that it can’t possibly mean anything. If it did mean something, then we would be able to read images, to parse them like writing, to read them aloud, to decode them and translate them. (p. 128)

Despite this sentiment, Elkins has elsewhere listed various competencies for what might constitute visual literacy and has edited a collection of essays on the subject (2008). John Debes has been credited with coining the term in 1969 (Horton, 1994, p. 5); however, Elkins (2008) has found otherwise: “A search of newspaper and magazine databases revealed that visual literacy has been in uncommon but intermittent use for over a hundred and fifty years” (p. 1). Perhaps, since visual literacy is a concept that has emerged from many different disciplines (Dwyer and Moore, 1994, p.3), its history varies from field to field.
A recent introductory textbook for language arts teachers defines visual literacy as:

an area of literacy that deals with what can be seen and how it can be interpreted. Visual literacy can be defined as the ability to understand communications composed of visual images as well as being able to use visual imagery to communicate with others. In other words, visual literacy is the ability to see, understand, think, create, and communicate graphically. (Tompkins, Bright, Pollard, & Winsor, 2008, p. 319)

While this definition seems straightforward, it is debatable whether visual literacy should be considered an area of literacy at all. There is a tendency to approach the understanding of visual images in the same way that language is approached, in terms of trying to impose a syntax or grammar onto visual language. In Visual Grammar (2006), Christian Leborg has written, “Visual language has no formal syntax or semantics, but the visual objects themselves can be classified” (p. 5). Lupton and Miller (1996) have suggested, “visual language is a metaphor” (p. 65). Elkins (2003) has also suggested that it is a mistake to think “that pictures have syntax and grammar in the same way writing does” (p. 125). Since visual modes of communication cannot be considered in the same terms as verbal modes, the use of the term literacy in visual literacy is problematic from the onset.
Visual literacy may be an increasingly discussed topic, because literacy is itself being redefined. As media becomes increasingly mixed, traditional literacy’s focus on learning to write and read has begun to seem insufficient. New, mixed media has created a conundrum for traditional literacy. Unsworth (2001) has written, “A great deal of work at the interface of theory and practice in this area remains to be done to enable all young learners to develop the critical multimodal literacies that are necessary for taking an active interpretive role in the societies of the information age” (p. 71). Peter Dallow (2008) has argued that it is the shifting definitions of literacy that make it difficult to define visual literacy. He has suggested that notions of literacy are culturally relative and “essentially socially constructed, and hence are mobile and situational in nature” (p.96). In the same essay, he went on to note that literacy standards and defined competencies continue to shift. A UNESCO document’s definition of literacy seems to go quite beyond the idea that literacy is simply being able to read and write. UNESCO (2004) has defined literacy as:

the ability to identify, understand, interpret, create, communicate, compute and use printed and written materials associated with varying contexts. Literacy involves a continuum of learning in enabling individuals to achieve their goals, to develop their knowledge and potential, and to participate fully in their community and wider society. (p. 13)

This definition of literacy moves toward inclusion of competencies in areas outside of traditional literacy. In addition to visual literacy, we now hear of scientific, economic, multicultural, and other literacies. In this way, visual literacy has become part of a larger debate around literacy itself.
The earlier-cited definition of visual literacy by Tompkins et al. and UNESCO’s definition of literacy, seem to suggest that skills associated with critical thinking such as identification and interpretation are a part of literacy. To simply read or write, or to see and create images, is not enough. Tompkins et al. (2008) have suggested, “viewing is more than just seeing. Students must be taught how to view. They need to learn that visual images, like words, convey ideas, beliefs, and values” (p. 321). In other words, according to them, critical thinking skills are a fundamental part of visual literacy. Regarded in this manner, visual literacy can essentially be equated with media literacy, which has been defined by the National Telemedia Council, in the United States, as:

the ability to choose, to understand – within the context of content, form/style, impact, industry, and production – to question, to evaluate, to create and/or produce and to respond thoughtfully to the media we consume. It is mindful viewing, reflective judgment. (cited in Silverblatt, 1995, p. 2)

This definition also suggests that images or media must be questioned, interpreted, evaluated, and, in a sense, decoded. An implication of this line of thinking is that visual literacy is something that has to be taught, and that students must not passively receive the media that is transmitted to them, but must question it. Tompkins et al. (2008) explicitly argued that visual literacy must be learned and is not naturally acquired. They wrote:

Visual literacy is learned, just as reading and writing are learned. Students learn to process visual images efficiently and understand the impact they have on viewers. The visually literate student looks at images carefully and critically to discover the intention of the image creator, just as a skilled reader discovers the intention of the author. Visual literacy allows students to gather information and ideas contained in images, put them in context, and determine their meaning in relation to that context and beyond. (p. 319)

Tompkins et al. (2008) also disagreed with Neil Postman in his assertion that children do not need instruction to watch television (p.321). In other words, this concept of visual literacy suggests that it cannot be attained simply through the naturally developed powers of visual perception that come through the stages of cognitive development.
The corporate graphic designer might think that visual literacy is separate from the media literacy proponents’ focus on critical interpretation. In the definitions cited above, by Tompkins et al. and National Telemedia Council, there seems to be more concern with the content of the media message than its style. On the other side, graphic design programs are generally more concerned with aesthetic principles of design. Outside the mainstream of academia, graphic design programs are often offered at trade schools or in the context of non-degree programs. The programs teach students to satisfy client needs, and as such tend to be practical and aligned with industry. Maud Lavin has been critical of the lack of critical thinking within the graphic design field. She has described graphic design as a field that is “client- and product-oriented … bent like most fields around self-justification, forced to talk formal visual issues and ignore its own impotency” (2001, pp. 2-3). In the glossary of Visual Grammar (2006), Christian Leborg includes a fascinating list of words, which include action, address, angle, background, center, close, color, contrast, direction, displaced, economical, frequency, irregular, opaque, plastic, repulsion, uniform, value, visible, and warm. The words in the glossary might be looked at purely in a design sense, separated from the sociopolitical realm. Critical perspectives, however, will show how these very design principles can often have greater significance, and can be used to manipulate a message. In a later section of this literature review, theories from the field of visual culture will show how all images can be critically questioned. Still, it cannot be denied that renowned artists in history have been celebrated for purely visual reasons, and have not been expected to critically participate in the world of sociopolitical issues. The phenomenologist Maurice Merleau-Ponty (2007) wrote: “The reproach of escapism is seldom aimed at the painter; we do not hold it against Cezanne that he lived hidden away at L’Estaque during the Franco-Prussian War” (pp. 352-353). In the modern context, would Cezanne’s ‘escapism’ be seen as impeding visual literacy development? Susan Shifrin (2008) has identified another approach to visual literacy “as being more ‘art for art’s sake’” (p. 108). Advocates of this approach suggest that art is something that has value in and of itself whether or not its skills translate into other academic domains (p. 106).
There are arguments that visual literacy comes naturally to a certain degree. Richard Jolley has pointed out that sophisticated cave paintings show that humans have an innate ability to represent objects through images (2010, p. 7). Edward H. Sewell has noted that symbolic artifacts, such as etchings on bone, can be traced back 35,000 years (1994, p. 135). Visual literacy theorists have even extended Noam Chomsky’s ideas of a universal grammar to suggest that visual literacy is innate (Horton, 1994, pp. 7-8). The work of child psychologist Jean Piaget is also cited to suggest that visual processes play a key role in cognitive development (Horton, 1994, pp. 11-12). Rudolf Arnheim (1997) argued that cognitive development depends on sensory perception and particularly visual perception. His reasoning was that “unless the stuff of the senses remains present the mind has nothing to think with” (p. 1). He argued that the visual sense is the best one to think with, because vision “is not only a highly articulate medium, but that its universe offers inexhaustibly rich information about the objects and events of the outer world” (p. 18). He suggested that visual perception plays a key role in cognitive operations such as “active exploration, grasping of essentials, simplification, abstraction, analysis and synthesis, completion, correction, comparison, problem solving, as well as combining, separating, putting into context” (p. 12). Following Arnheim’s reasoning leads to the conclusion that visual literacy skills are at least partially acquired naturally, through simply being in the world, provided of course that one is able to see. Thus, visual literacy is quite different from traditional literacy, because people do not learn to read or write without specific instruction or guidance.
We are left then with a muddle: what is visual literacy? Mixing together the different perspectives I have read, I would suggest that visual literacy involves a combination of traditional, media, and technological literacies, artistic and design abilities, basic and innate visual perception abilities, and a metacognition of how we visually perceive things. By metacognition, I refer to the idea espoused in information processing theories of cognitive psychology which suggests there is such a thing as cognition about cognition, which leads to planning, monitoring, and evaluating skills (Woolfolk, Winne, Perry, & Shapka, 2009, p. 264). Following the reasoning of Arnheim, it is reasonable to suggest that there can be cognition about visual perception. In short, I would argue that visual literacy is something that exists on a sliding scale. As we study both the visual realm in a conscious and reflective manner and simply experience the world, our degree of visual literacy increases.