Is my symbology clear?
Symbology is critical. If your map readers cannot tell what a symbol is or what it means, your map is potentially misleading or even useless. Three things will help make your symbology more easily understood by map readers: familiar symbols, intuitive symbols, or good explanations for symbols that are not familiar or intuitive. From their previous map use experience, many map readers will already be familiar with some symbols, such as a blue line for a river or a green polygon for a patch of vegetation. When possible, use these familiar symbols. For features that do not have a familiar representation, try picking a symbol that your readers will intuitively understand such as a picture of a person walking with a stick to symbolize a trail. For symbols that are not familiar or intuitive, provide a good explanation in a legend or through explanatory text.
Figure 3: Color hue and shape, and to a lesser extent orientation, naturally evoke qualitative differences among features. (Image courtesy of Map Use, Sixth Edition)
To also improve clarity, when you have a number of features that will overlap, try using a cased symbol (one with an outline). This will let readers distinguish all the features, even when they overlap one another.
