ABSTRACT
One of the oldest forms of visual communication among people involves the use of pictorial representation. The terms ‘symbol’, ‘pictograph’, ‘pictogram’, ‘icon’ and ‘glyph’ all refer to commonly used pictorials. These terms will be used to mean more or less the same thing in the present chapter (although their strictly correct usage may be different from that used here). The term ‘icon’, for example, is widely used in computer applications. A symbol is essentially a picture or visual representation which depicts one or some of the features of the referent (real-world object or concept) it represents.
