2.5 Visual communication
As discussed in Reading 2.4, written text has major limitations in representing relationships between things when they do not follow the linear structure of the text. Relationships can be extremely complex, even circular, as you will see in this block. In particular, the linear sequence of text is not able to clearly show context, elements, structure, processes and functions of systems. The nested nature of systems within systems is also very difficult to show. In many ways, writing favours an analytical approach, since you can go into an increasing level of detail as you move down the page. A visual approach to communication can take a radical departure from the linear logic of oral/written communication. Maps, diagrams, photographs, and physical models, are all forms of visual communication. The strength of these techniques is that they can focus on relational logic. Compare the following written example (Box 1) to a diagrammatic example (see Figure 2.4) which essentially conveys the same information.
Jane is married to Tom and they lived at number 8. Tom's sister, Dawn, lives at number 20 and has three children: Peter, Paul and Mary. Dawn's partner, Derek, left her four years ago and moved to Scotland, and she is now living with John. John has two children of his own, Tim and Nicholas, from his marriage to Julie. Julie's father, Alf, works in the same factory as Tom's father, while Dawn's mother and Jane's mother went to school together. Alf and Millie live at number 34. They used to live at number 6, but moved when the children left home. Dawn has two older brothers, one of whom has moved away. Keith and Pamela are Tom's parents, but Pamela died last year. Keith now lives alone at number 18.
Good visual communication, as in the above example, using a range of diagramming techniques, is clearly much better at communicating relationships among subjects. The use of the written word does not necessarily have to be eliminated, but it is no longer constrained by sentence structure. Visual communication's focus on relational logic can be further subdivided into forms which communicate structural relationships and those which communicate functional relationships. A structural representation is essentially a static picture of the situation. Maps for example, are used to show the relationship between landscape features such as roads, towns and recreational areas. The only way to find out how the landscape has changed over time is to overlay maps produced at different dates one on top of the other. Other forms of structural representation include the diagram (Figure 2.4) that you have met in this reading. Functional representations focus on communicating change over time. These include the sign graph and system dynamics diagramming techniques that you will meet in later readings.