EFFECTIVE USE OF ILLUSTRATIONS IS AN IMPORTANT FACET of instructional message design. How "realistic" must visuals be? What are the effects of static and dynamic visuals on learning? What makes a good instructional illustration?

We often think that pictures should faithfully mirror nature. According to picture perception theory, however, realism is not so much a matter of copying as it is of conveying.

For instance, given a mere suggestion of an object, people "fill in the details" of what they already know about it.

One implication of this is that instructional designers can spend more time and effort considering the deeper semantic and psychological effects of images rather than focusing on the degree of perceptual realism.

This is a realistic image of a letter,

which often symbolizes email on a

website.However, the following less

realisitc icon conveys the same

concept just as effectively:

This symbol, which warns of electrical

shock hazard, is arguably more

appropriate than a realistic depiction.

In certain instances, static visuals can facilitate knowledge acquisition when they accompany text. Here are some guidelines for using static visuals:

• Illustrations that contain text-redundant information can aid learning. Illustrations that are not text-redundant neither help nor hinder learning.
• Cues such as size, position, style, and color may direct attention but may not significantly aid learning.
• In the context of learning to read, illustrations are not very helpful.
  

A 35mm single lens reflex camera.

Research on the effects of dynamic visuals on knowledge acquisition are limited. However, early studies of instructional film indicate that:

• Animation can aid learning if motion is a critical attribute of the concept being presented.
• Animation can signficantly aid the learning of a procedural task.
• Animation used to enhance the realism of a presentation does not have a significant effect on learning.
  

When teaching the concept

 of the earth's rotation, a dynamic

visual is more effective than a

static one because motion

is a critical attribute.

When teaching a psychomotor

 skill such as juggling, an animation

demonstrating the skill is more

effective than written procedures alone.

Perhaps the most important tip to remember when designing instruction is to consider the effect of visuals on knowledge acquisition. Avoid falling into the trap of "technology for technology's sake." 

Graphics courtesy of

&

Cathy Tobias, Instructional Designer