Effects of training and representational characteristics in icon design

Icons are a very important component of graphical user interfaces. However, icon design is still predominantly artistic in nature and as a result icon selection is generally based on usability evaluations after a set of alternative icons are developed. This process tends to be time-consuming and costly. In this research, we address the issues ofwhat should be depicted in an icon, given the function it should represent, and how training affects the performance of novice users when using an iconic interface. A set of 36 concrete icons (12 functions) were selected and tested with a total of 30 participants. The experimental results indicate that complete representations are generally superior for both untrained and trained participants. Results also show that trained participants had shorter response times when compared to untrained participants. Further analysis suggests that ambiguity, uniqueness and dominance are three important aspects to consider when designing and developing icons. Applications of this research include the design of appropriate icons for graphical user interfaces prior to usability testing and the importance of a short training period to illustrate the composition of an icon in an effort to improve the mental model associated with each design.