Abstract

This paper describes an experiment comparing two methods for viewing hierarchically clustered networks. Traditional full-zoom techniques provide details of only the current level of the hierarchy. In contrast fisheye views, generated by the "variable zoom" algorithm described in this paper, provides information about higher levels as well. Subjects using both viewing methods were given problem solving tasks requiring them to navigate a network, in this case a simulated telephone system, and to reroute links in it. Results suggest that the greater context provided by fisheye views significantly improved a user's performance of the tasks. They were quicker to complete their task, and they made fewer unnecessary navigational steps through the hierarchy. This validation of fisheye views is important for designers of interfaces to complicated monitoring systems, such as control rooms for supervisory control and data acquisition systems, where efficient human performance is often critical. However, control room operators remained concerned about the size and visibility tradeoffs between the fine detail provided by full-zooms, and the global context supplied by fisheye views. Specific interface features are required to reconcile the differences.

Citations