Icons are included because “this is the things to do” in a graphical system today. Proper icon design is important from an acceptance, learning and productivity perspective.

The following factors influence an icon’s usability:

1. Familiar Is the icon legible? Familiarity will reduce learning time. Lack of familiarity requires learning the icon’s meanings. Very unfamiliar icons require a great deal of learning. Experience often makes words and numbers more familiar to a person than symbols. Graphic symbols may be more visually similar to each other.

2. Clear and legible Is the icon legible? Does the shape, structure and formation technique on the screen permit a clear and unambiguous depiction of what it is? Screen resolution should be sufficiently fine to establish clear difference of form at the normal working distance. The resolution and pixel shapes for screen differ from one another. Icons must appear correctly and consistently no matter what kind of screen is used. If color is used, it should contrast well with the background, poor clarity would lead to identification errors and slower performance.

3. Simple Is the icon simple? Is the shape clean and devoid of unnecessary embellishment (decoration)? Too many parts will only confuse the screen viewer.

4. Consistent Are families of icons consistent in structure and shape? Are the same icon displayed on different screen consistent in shape and structure? Are the same icons displayed in different sizes also consistent in structure and shape?

5. Direct How “sign-like” is the icon; how well does it convey its intended meaning? For concrete objects and actions, direct links are more easily established.

6. Efficient In some situation, a graphical screen may be less efficient, consuming more screen display space than a word or requiring more physical actions by the user than text. A telephone directory of 50 names and numbers listed on an alphanumeric screen may consume the same screen space required for and manipulation of 15 file cards. Icons strength lies in situation where small area of space is required to communicate the concept.

7. Discriminable The symbols chosen must be visually distinguishable from other symbols. A person’s power of differentiation for shapes and other forms of codes have been experimentally determined over the years. A person’s ability to discriminate alphabetic or alphanumeric information is much more potent.