When developing learning materials, most instructional designers and trainers rarely give much thought to how they use visuals and graphics. Typically, they just add them as a way to liven up dull looking text.
In contrast, as most graphic designers and artists know well, there is an entire vocabulary and language connected with the use of visuals. This is something rarely included as part of conventional instructional design training. A pity, because it is a language which instructional designers and trainers would get a great deal of benefit from knowing.
If you are interested in learning more about the language of visuals, as good a starting point as any is an understanding of the five instructional functions for graphics. These functional categories are as follows:
Decorative visuals: used to make instruction more appealing and motivating. They typically do not have a strong association with the instructional content. Interestingly, in a study of sixth grade science textbooks in the US, Richard Mayer found that over 85% of graphics fell into the decorative category.
This statistic seems to support the view expressed in the opening of this article - that many instructional designers pay little attention to the significance of visuals and graphics. In the light of this finding, it's probably fair to say that decorative graphics should be used with caution.
Representative visuals: used to make information more concrete. They convey information quickly and easily, reducing the need for lengthy textual explanation.
Organisational visuals: help learners understand the structure, sequence and hierarchy of information and help people integrate that into their existing knowledge. Examples include charts, graphs and displays that help people see relationships between elements.
Interpretive visuals: used to help learners understand difficult and ambiguous or abstract content. In general, they help make information more comprehensible. Examples include models of systems and diagrams of processes.
Transformative visuals: used to make information more memorable. They are intended to aid learners' thought processes. They focus more on helping the learner understand than on presenting content. Transformative visuals can be a little unconventional and because of this are not widely found in learning materials.
In conclusion, we've all heard the phrase "a picture is worth a thousand words". And many people accept this wisdom without question.
In fact, just because something is visually composed doesn't necessarily make it more valid or easier to understand. A poorly designed visual or graphic could just as easily impede learning as facilitate it.
Indeed, a poorly designed graphic where the purpose and instructional function are mismatched might need a thousand words to help explain it clearly to learners.