One from Column A and one from Column B: Simultaneous vs. Sequential Menus

Conclusion

Our results suggest that simultaneous menus may improve user performance in certain circumstances. For menu structures that can be appropriately decomposed into simultaneous menus, this arrangement may improve user performance in situations that involve significant amounts of backtracking. The choice between simultaneous and sequential menus should be made on the basis of the expected task: if users are expected to make multiple selections from two or more menus, simultaneous menus may provide better performance. Specifically, simultaneous menus might be best suited for use with open-ended ``exploratory'' tasks.

Much of the literature on menu structure design has been narrowly focused on analysis of the breadth vs. depth question in hierarchical menu structures. Although clearly important, these investigations may present an overly simplistic view of the problem of menu structure design. Our study presents one alternative to strictly hierarchical menus, along with some evidence that simultaneous menus might lead to improved performance in certain circumstances.

More fundamentally, comparisons that limit the parameters of menu designs to depth and breadth may not account for some of the more subtle factors that affect performance. Studies of menu structures with different shapes [Norman and Chin, 1988] and with differing amounts of contextual information [Zaphiris et al., 1997] have shown that performance can be influenced by the type of task, the amount of context given, and the shape of the menu.

Although our results provide encouraging evidence in favor of the use of simultaneous menus in some contexts, consideration of this design alternative may complicate issues more than it clarifies. Further examination of the utility of these different menu arrangements, the effects of menu breadth and depth, and the influence of the type of task involved, will be necessary for development of robust guidelines for menu design.