A comparison of simple hierarchy and grid metaphors for option layouts on small-size screens

Abstract Modern, technologically driven society is characterized by an increase in the rate of mobile device use and an increase in the extent to which these devices are used for more complex tasks than search for phone numbers. While direct consequences of screen-size reduction on task performance are well known, data are lacking on the impact of layout of multiple options in a complex task environment. In this paper we describe the results of an end-user study in which we compared two basic interface designs for the layout of multiple options: a simple hierarchy and a single layer grid. These two designs were presented to users on two screen sizes; a larger size approximating the size of a standard laptop or desktop screen and a smaller size approximating the size of a PDA screen. This study illustrates that while task performance in accessing information was superior using the grid interface rather than the simple hierarchy interface, users preferred the simple hierarchy interface. Even as the complexity of the task increased, the physical size of the screen had a significantly bigger impact on task performance than did the task complexity. These findings indicate that the grid layout should be used when task performance is of the paramount concern and the complexity of choices is not expected to be large. When user preference/satisfaction is more important than task performance the appeal of the simple hierarchy layout may supersede the cost in performance it entails.