The Calibration and Optimisation of Speed-Dependent Automatic Zooming
Andrew Wallace
Department of Computer Science
University of Canterbury
Abstract
Speed Dependent Automatic Zooming (SDAZ) has already been shown to be an effective navigation technique for document browsing. We investigate here three further aspects of SDAZ. We begin with an analysis of the existing methods of document navigation. We present a taxonomy of document navigation goals and examine how these goals are supported by the current navigation techniques. Our focus here is on how SDAZ fits in with existing techniques and how it can assist in the support of these different goals. Our second area of investigation, which is the main focus of this work, is on the issues surrounding the calibration of SDAZ systems. The extent of the difficulty of obtaining an optimal system has not been made clear in the previous literature. We discuss in detail the implementation and fine-tuning issues surrounding SDAZ systems, with a view to obtaining an optimal implementation. Finally, using our SDAZ system we perform a small formal evaluation comparing SDAZ to rate-based scrolling. SDAZ is a modified rate-based system, and our evaluation shows it is superior to a standard rate-based system, and therefore proves that the modifications are worthwhile.
