Some Basic Guidelines
Visual aids can enhance a presentation dramatically when used properly, or they can become distracting, time-consuming, and counterproductive when used haphazardly. Here are some basic guidelines for using visual aids effectively.
Types of Visual Aids and Their Uses
Publishers traditionally divide visual aids into two broad categories:
- Illustrations, which are graphic in nature and include line drawings, paintings, photographs, screen captures, maps, diagrams, charts, and graphs
- Tables, which are text-based rather than graphic-based
Within the illustrations category, there are a variety of distinctions serving different functions.
Drawings, paintings, photographs, and screen captures are used to show how something looks in a realistic style. Maps convey similar visual information symbolically.
Diagrams are commonly divided into charts and graphs. Charts use images such as bars, lines, and pies to represent relationships between numbers and other variables. Graphs use images such as arrows to represent relationships between parts and wholes or between ideas.
Common charts include:
- Bar charts, used to represent proportions
- Pie charts, representing percentages
- Line charts, representing a sequence of events
- Histograms, representing frequencies
Graphs can be categorized by their geometric layout. Some are linear, with lines, arrows, or steps indicating a flow of information in a single direction. Others are circular, with information flowing in a cycle around the perimeter of the circle, or with the interior of the circle divided into pie slices to represent parts of a whole. Some combine linear and circular features, with a circle in the center of arrows pointing to or away from it to represent a relationship of a whole to its parts or cause to effect.
Tables are usually rows and columns of numbers, representing relationships between data. But they can also be rows and columns of words, representing conceptual or logical relationships, as with the summary table below:
Types of visual aids and their functions
When to Use Visual Aids
There are a few situations when visual aids are especially useful. These include:
- When a visual aid can convey information that words cannot express adequately. For example, a photograph will always be a more complete representation of someone’s features than a verbal description.
- When a visual aid is easier to process than a verbal description. An example would be using a table or chart to summarize information that would be cumbersome to convey verbally.
- When a visual aid can convey information more quickly than a verbal description. A good diagram can often sum up the highlights of information that would take chapters to convey fully in words.
- When a visual aid can amplify the clarity of a verbal description by highlighting or reinforcing key points.
It’s also important to know when not to use visual aids. In traditional publishing, overuse of graphics and color can skyrocket printing expenses. In digital publishing, the advent of PowerPoint has created a tendency for amateur designers to compulsively add graphics to every slide, even when they do nothing to enhance the verbal message being conveyed, or worse yet, distract from it. The general best practice is to limit visual aids to the simplest ones necessary to express the main point of the text, and to eliminate visual aids that do not serve this function.
Where to Place Visual Aids
A good rule of thumb is to place a visual aid after the paragraph where the information it conveys is first mentioned. This can mean placing it below the paragraph or to the side of it in a two-column format. There are exceptions where it may be useful to place a visual aid before the relevant text, as when seeing the picture first would make the text more meaningful.
How to Insert Visual Aids
When inserting visual aids into text documents for publishing purposes, the best practice is to save visual aids as separate files and place bracketed notes in the text document indicating where to insert which file. This keeps text document files from growing too large, and it makes it easier for graphic designers to edit visual aids.
How to Label Visual Aids
Labels for visual aids include captions and legends. These terms are increasingly used interchangeably, but there are some differences.
Captions serve the same function for visual aids that titles do for books and headlines do for articles. They should be descriptive phrases rather than complete sentences. They were traditionally placed above visual aids, but are today often placed below them (as in the illustrations in this article).
Legends are explanations of visual aids. Unlike captions, they are complete sentences. They usually appear below visual aids.
