Users working with documents that are too large and detailed to fit on the user's screen (e.g. chip designs) have the choice between zooming or applying appropriate visualization techniques. In this paper, we present a comparison of three such techniques. The first, focus plus context screens, are wall-size low-resolution displays with an embedded high-resolution display region. This technique is compared with overview plus detail and zooming/panning. We interviewed fourteen visual surveillance and design professionals from different areas (graphic design, chip design, air traffic control, etc.) in order to create a repre sentative sample of tasks to be used in two experimental comparison studies. In the first experiment, subjects using focus plus context screens to extract information from large static documents completed the two experimental tasks on average 21% and 36% faster than when they used the other interfaces. In the second experiment, focus plus context screens allowed subjects to reduce their error rate in a driving simulation to less than one third of the error rate of the competing overview plus detail setup

The purpose of this paper is to introduce a replicable WWW protocol analysis methodology illustrated by application to data collected in the laboratory. The methodology uses instrumentation to obtain detailed recordings of user actions with a browser, caches Web pages encoutered, and videotapes talk-aloud protocols. We apply the current form of the method to the analysis of eight Web protocols, visualizing the structure of the interaction and showing the strong effect of information scent in determining the path followed.