||The psycho-physical, cognitive and intellectual process of decoding cartographic symbols and making sense of features and relationships portrayed on a map (see map image and map). Map-reading is similar to the reading of a book, news report or other literary work insofar as an accurate and efficient interpretation depends on not only a vocabulary shared by author and reader but also a common understanding of how information should be structured for ready communication. Successful map-reading thus relies heavily on the user\'s experience with cartographic vocabulary (see symbolization), map projection, map scale, and common forms of topographic and thematic maps â€” experience at least sufficient to inculcate a belief that map-reading will be informative â€” as well as some prior understanding of the phenomena portrayed (Eastman and Castner, 1983).
Map-reading differs markedly from verbal reading (Balchin, 1976). Literary texts rely on the vocabulary and grammatical structure of everyday speech, in which words are organized linearly in sentences, grouped in turn into paragraphs and chapters. Within sentences, the familiar sequence of subject-verb-object affords a logical framework for describing who did what to whom. And within paragraphs â€” at least in well-written works â€” the topic sentence establishes the context for a coherent sequence of sentences in which the speaker or writer adds new information to what the listener or reader has already been told (Williams, 1990). By contrast, maps often rely on abstract geometric symbols, which few if any readers use with the regularity of verbal language. And even maps consisting largely of pictograms or words must present their symbols in a two-dimensional format unable to dictate the sequence of decoding. Perhaps the closest similarity between maps and literature is the index, which points to specific features or facts with grid coordinates or page numbers.
Semiologist Jacques Bertin (1983) made an important distinction between map viewing and map-reading. Simply put, some maps are made to be read whereas others are made to be seen. In advertising and political propaganda, for example, a map to be seen will blatantly announce the locational convenience of a firm\'s retail outlets or the unfair threat posed by a small nation\'s larger neighbours. Although an accurate interpretation demands a minimal appreciation of the map\'s context and objective, little conscious decoding is required. By contrast, a map to be read imposes a \'mental cost that the viewer must expend to extract information\' (MacEachren, 1995, p. 209).
Contrast and similarity among map symbols provide rudimentary guidance for map-readers, who seem proficient in identifying edges and processing information in chunks (Marr, 1982). Evidence suggests that the reader\'s eyes are attracted more readily to darker symbols, thicker lines and larger labels than to lighter symbols, thinner lines or smaller type (MacEachren, 1995, pp. 51-149). Cartographers and other graphic designers are thus advised to develop and reinforce a graphic hierarchy by concentrating this \'data ink\' on the symbols representing the more salient features (Tufte, 1983, pp. 91-105). Equally important is recognition of the variety of map-reading tasks that can be improved or hindered by a specific design or juxtaposition of features (Olson, 1976). Authors must also be wary that a viewer\'s reaction to the map\'s aesthetic appearance can enhance or diminish interest and expectations (Wood, 1993).
Animation and interactive electronic multimedia promise more structured cartographic communication insofar as temporal sequences of maps, diagrams, photographs and blocks of text can approximate the linear coherence of a narrative dramatized on film or video (Monmonier, 1992). No less important than graphic sequencing is the potential for adding a sound channel and customizing the presentation to the interests and experience of the \'reader\' (see visualization).Â (MM)
References Balchin, W.G.V. 1976: Graphicacy. The American Cartographer 3: 33-8.Â Bertin, J. 1983: Semiology of graphics: diagrams, networks, maps, trans. W.J. Berg. Madison: University of Wisconsin Press.Â Eastman, J.R. and Castner, H.W. 1983: The meaning of experience in task-specific map reading. In D.R.F. Taylor, ed., Graphic Communication and Design in Contemporary Cartography. New York: John Wiley and Sons, 115-48.Â MacEachren, A.M. 1995: How maps work: representation, visualization, and design. New York: Guilford Press.Â Marr, D. 1982: Vision: a computational investigation into the human representation and processing of visual information. San Francisco: W.H. Freeman.Â Monmonier, M. 1992: Authoring graphic scripts: experiences and principles. The American Cartographer 19: 247-60, 272.Â Olson, J.M. 1976: A coordinated approach to map communication improvement. The American Cartographer 3: 151-9.Â Tufte, E.R. 1983: The visual display of quantitative information. Cheshire, Connecticut: Graphics Press.Â Williams, J.M. 1990. Style: toward clarity and grace. Chicago: University of Chicago Press.Â Wood, M. 1993: The map-user\'s response to map design. The Cartographic Journal 30: 149-53.
Suggested Reading MacEachren, A.M. 1995: How maps work: representation, visualization, and design. New York: Guilford Press.Â Muehrcke, P.C. and Muehrcke, J.O. 1997: Map use: reading, analysis, interpretation, 4th edn. Madison, Wisc.: JP Publications.