Critical zones in desert fog

Abstract

In this paper, we introduce the problem of "desert fog," a condition wherein a view of an information world contains no information on which to base navigational decisions. We present a set of view-based navigational aids that allow navigators to find their way through desert fog in multiscale electronic worlds. Prototypes of these aids have been implemented in the Landmarking and ZTracker systems. We introduce the concept of critical zone analysis, a method of grouping objects according to their visibility in views of the information world rather than their spatial layout. This concept was derived from a formal analysis of desert fog using view-navigation theory. Our analysis informally extends view-navigation theory to accommodate spatial multiscale worlds and is detailed in the paper.