Variable zoom : a new display technique for large hierarchical networks
Zhengping Zuo · Summit (Simon Fraser University) · 1992
Large hierarchical networks are widely used in supervisory control systems, such as those in telecommunications network management, power distribution, and industrial process control.These networks are becoming increasingly difficult for operators to understand and operate correctly.To help overcome navigation problems encountered in traditional methods for displaying such networks, this thesis proposes a new display technique, called a variable zoom, to represent large hierarchical networks.It combines hierarchical representations with a generalized fisheye strategy pioneered by G.W. Furnas.The variable zoom "nests" one or more detailed views into one or more levels of context in order to improve navigation and user understanding.The detailed regions are uniformly magnified while the levels of context are gradually demagnified.The magnification/demagnification factors are adjusted according to the environment and the user's requests.Two prototypes of the variable zoom method have been completed, one for an abstract network, the other for a human factors experiment.A preliminary human factors experiment showed that the variable zoom technique was significantly better than a traditional uniform zoom technique in this experiment.