



Carol Traynor and Marian G. Williams
Computer Science Department
University of Massachusetts Lowell
Lowell, MA 01854 USA
ctraynor@cs.uml.edu (+1 508 934-3385)
williams.chi@xerox.com (+1 508 934-3628)
Off-the-shelf geographic information system software is
hard to use unless you have sufficient knowledge of
geography, cartography, and database management
systems; are computer-literate; and invest sufficient time to
become accustomed to an interface that reflects the system
architecture. It is best suited for use by specialists, or for
people who can afford to make the investment of time and
effort to become specialists.
We became interested in Geographic Information Systems
(GIS) through a project in which some social scientists at
our university are attempting to develop a GIS application
for use by residents of the inner-city neighborhoods of
Lowell, MA. The application will contain data about
demographics, schools, crime, hospital emergency use,
toxic waste sites, etc. The goal is to empower residents to
lobby more effectively for change in their neighborhoods.
It became clear early in the project that, despite
consultations with a GIS expert [3], the social scientists
were finding the software very difficult to use. It also
became apparent that there is little hope that community
residents with no computing experience will be able to use
the software.
Two additional projects have given us added insight into
the difficulties of use of GIS. We have developed materials
for introducing GIS to public school teachers who think
they want to incorporate mapware into their curricula [4],
and we have asked computer science graduate students to
use various off-the-shelf GIS software packages as part of
their graduate HCI classwork.
We have to date used, and have watched the various users
mentioned above attempt to use, seven prominent off-the-
shelf GIS software packages. Two of the GIS packages are
Macintosh-based; five are PC-based. Five have mouse-
driven graphical user interfaces (GUIs), one has a
command line interface, and one requires both mouse and
keyboard to navigate through menus. We generalize from
these seven packages in order to explore the issues that
make software of this type hard to use by non-specialists.
According to a task analysis, performed by Knapp [2], of
GIS use by specialists, GIS tasks use four primary "visual
operators": locate, identify, compare, and associate. The
user interfaces of the GIS packages we have looked at do
not explicitly support these operations. Rather, users must
navigate through levels of menus that reflect the
architecture of the software. In order to become adept at
using the GIS software, they must learn to map their tasks
onto that architecture.
DOMAIN KNOWLEDGE AND NAVIGATION
A non-specialist user approaching a GIS will expect to
work with maps. But in the GIS software we have looked
at, the word "map" may not appear in its expected sense.
For example, in one of the packages, a map is opened by
selecting Geographic from the File menu, then selecting
Use from the Geographic submenu, and finally typing a
filename into a dialog box. The word Map appears in the
View menu, but is used to define a cartographic view, not
to open a map. In another package, a map is opened by
selecting Open Table from the File menu.
We have watched computer science graduate students
spend as much as an hour trying to figure out how to open a
map in one particular GUI-driven GIS, and give up in
frustration. They do not have a cartographer's vocabulary
(terms like view, overlay, and thematic layer), nor have
they a cartographer's understanding of the components that
make up a map and of the relationships between those
components.
We have looked at how the GIS packages support Knapp's
four visual operators (locate, identify, compare, and
associate), and have found that users may have to translate
these operations into complex series of steps, using terms
and concepts from cartography and database management.
Accomplishing user tasks in the GIS software packages that
we have looked at is not intuitive for non-specialists
because the tasks have to be carried out using commands
that reflect the software implementation and require
knowledge from several technical domains. Thus non-
specialist users must translate their tasks, rather than having
the computer support their work.
In order to support the work of the non-technical users -
and to free them from dependence on surrogate users - we
are engaged in the participatory design of a new GIS. The
users who are currently involved in the project are school
teachers and social scientists. We expect to work with
community activists from the Lowell, MA neighborhoods,
as well. The interface of the GIS will directly support the
users' tasks and will protect them from having to know
about how data are stored and how maps are drawn.
Abstract
Geographic Information System (GIS) software evolved
out of the fields of geography, cartography, and database
management. As a result, off-the-shelf GIS software
requires the user to have or to acquire considerable
knowledge of these fields. Navigation through the
interfaces of most off-the-shelf GIS software is difficult
because they support a system architecture view, rather
than a view of the user's work. These problems are
compounded for users with little computing experience. In
many workplaces, a single technical user becomes the local
GIS expert, and acts as a surrogate for other users who have
neither the expertise to use the software nor the resources to
acquire that expertise. In this paper, we summarize our
analysis of what makes GIS so hard to use, and describe
our research directions toward designing effective GIS
software for non-specialist users.
Keywords:
geographic information systems, partici-
patory design, task analysis.
Introduction
A geographic information system is software for the
acquisition, storage, analysis and display of geographic
data. It combines cartographic tools with a data base
management system.
Locating
Locating means determining or specifying the position or
boundaries of an object in the data, to put it in a spatial
context [2]. The GIS software may offer "geocoding" or
"address matching," to associate database entries with
points on a map, but it may not explicitly offer "locating."
(Of course, the fact that the user has to associate database
entries with map locations, rather than associating values
with map locations, is an example of how operations are
structured by the architecture of the program, rather than by
user tasks.) In GIS software, locating may require the user
to understand such cartographic concepts as geocoding,
address matching, polygons, and polylines, as well as such
database concepts as table, attribute, and query.
Identifying
Identifying means ascertaining the definitive characteristics
of an object in the data.. It includes categorizing an entity
and distinguishing it from other entities [2]. In GIS
software, identifying may require the user to understand
such concepts as table, attribute, and query (in the database
sense) and theme (in the cartographic sense), as well as
how to use a spreadsheet.
Comparing and associating
Comparing is examining the differences and similarities of
objects. Associating is establishing relationships between
objects [2]. In GIS software, comparing and associating
may require the user to understand such concepts as
overlay and thematic layer (in the cartographic sense) and
query (in the database sense).
GIS FOR NON-TECHNICAL USERS
In many workplaces, a single specialist becomes the local
GIS expert, and acts as a surrogate for other users who have
neither the expertise to use the software nor the resources to
acquire that expertise [1]. We observe this phenomenon
happening within our university, where the social scientists
mentioned above have hired some computer science
graduate students to become GIS specialists. These
specialists become immersed in the terminology of GIS and
in a way of thinking about information that the architecture
imposes on them. Even when coached, these specialists
have trouble communicating with the users they serve,
because of the burden of translating between GIS-speak
and the workplace terminology of the users.
Acknowledgments
This research is supported in part by U.S. Department of
Education grant number R117E30237, Improving the
Success Rate of Adapting Technology for the Classroom.
We are indebted to J. Nicholas Buehler for his
valuable help and advice.
References
1. Garson, G. David and Robert S. Biggs, Analytic
Mapping and Geographic Databases, Sage
University Paper series on Quantitative Applications in the
Social Sciences, series no. 07-087 (Newbury Park, CA:
Sage), 1992.
2. Knapp, Loey, "A Task Analysis Approach to the
Visualization of Scientific Data," Ph.D. dissertation,
University of Colorado, 1994.
3. Kuhn, Sarah, Charles Richardson, and Marian G.
Williams, "Meeting of the Minds: The Challenges of
Interdisciplinary and Inter-occupational Communication,"
in PDC ‘94: Proceedings of the Participatory Design
Conference. R. Trigg, S.I. Anderson, and E.A.
Dykstra-Erickson (Eds.). Chapel Hill, NC, USA, 27-28
October 1994 (Palo Alto, CA: CPSR), p. 147-148.
4. Traynor, Carol, James Pash, and Marian G. Williams,
"Bringing Users into the Discussion of an Unfamiliar
Technology," in PDC ‘94: Proceedings of the
Participatory Design Conference. R. Trigg, S.I.
Anderson, and E.A. Dykstra-Erickson (Eds.). Chapel Hill,
NC, USA, 27-28 October 1994 (Palo Alto, CA: CPSR), p.
131.