In turning to consider the use of tables, graphs, diagrams and other illustrations in the presentation of information, we are not changing our topic. Our subject is still clear communication, and we are still discussing how to make precise, manageable statements using language. Words, graphs and drawings are all visual patterns used to symbolise or represent meaning. In both graphic statements and verbal statements, we use a variety of hieroglyphics-dots, dashes, and other marks on paper-as symbols to carry information. Words, after all, are made up of letters which are composed of combinations of lines and circles; for example, the difference between 'o', 'p', 'd', and 'b' lies only in the positioning of the line tangential to the circle. So words and drawings are not conflicting or competing modes of expression. They are, at most, extremes on a continuum, with words at one end making minimum use of the visual appearance of the signals, and with drawings and graphic presentations at the other end making maximum use of the visual appearance of the signals.
In earlier chapters, we have discussed how statements in words often cause difficulty for receivers because they contain unfamiliar vocabulary or signals, because they are too long and complex, or because they require the reader to hold in mind too many inter-related clauses and conditions. Visual statements can be difficult for the receiver for similar reasons: they may