The Geographer's Desktop: A Direct-Manipulation User
Interface for Map Overlay
Max Egenhofer and James Richards
Abstract
Many spatially aware professionals use the manual process of map
overlay to perform tasks that could be done with a GIS. For
instance, they could be using GIS technology for work in
environmental sciences and design fields, however, they are often
not doing so because they lack the computer expertise necessary to
run a GIS. The user interface of current GISs has been frequently
cited as a major impediment for a broader use of GISs. Popularity
and success of metaphor in other areas of human-computer
interaction suggests that visual, direct manipulation user
interfaces are especially attractive and easy-to-learn for
non-computer experts. Many GISs use map overlay as a command-line
based interaction paradigm. An interface to GIS that is a
visualization of the map-overlay metaphor would enable experts in
the spatially aware environmental sciences to more easily use GIS
as a regular tool. To overcome this shortcoming, a new direct
manipulation user interface based on the map-overlay metaphor has
been designed and prototyped. It is well embedded within the
successful Macintosh desktop and employs the particular
characteristics of metaphor, direct manipulation, and iconic
visualization. We create a geographer's desktop by replacing
the familiar notions of files and folders with the concepts of
map layers and a viewing platform on which layers can
be stacked. A visualization of this user interface is presented.
Particular attention is given to the way users can change the
symbology of layers placed on the viewing platform.