Component modes of graphical communication

The particular characteristics of communication by graphics have always been controversial. It has been argued by some (e.g. Goodman, 1969; Scholtz, 1993) that the realm of graphics is to be distinguished from that of text or other forms of language on syntactic grounds. Another line of thought is that this fails to get us far unless we devote careful attention to semantics at the same time (Lee, 1999). Syntax is indeed in some sense crucial, but can only be understood and clarified by reference to the semantic properties of the expressions, symbols, or whatever we wish to call them, that occur in the graphical medium. One way of developing this line of thought is to consider the uses of graphical expressions. Such uses are of course common. We see pictures, diagrams, symbols of many graphical kinds in use every day. It is instructive to consider these, but often we will find that their uses are somewhat removed from the immediacy of the communicative context from which they are originally derived. Some aspects of their communicative function in those contexts may have ossified, atrophied even, in the course of a process whereby they have become conventionalised in their usage. Perhaps we can better understand these communicative functions if we study a situation which is relatively unconventionalised, but in which conventions can be allowed to emerge. We can then investigate what happens to the roles and uses of graphical expressions during this emergence.