INTERFACE APPARENCY AND MANIPULATABILITY:
COGNITIVE GATEWAYS THROUGH THE SPATIAL VISUALIZATION
BARRIER IN COMPUTER-BASED TECHNOLOGIES
Kent L. Norman
Department of Psychology and the Human/Computer Interaction Laboratory
University of Maryland
College Park, MD 20742-4411
CONTACT INFORMATION
Email: kent_norman@umail.umd.edu, phone: (301) 405-5924, fax: (301)
314-9566
WWW PAGE
http://www.lap.umd.edu/LAPFolder/NSFIA/abstract.html
PROGRAM AREA
Usability and User-Centered Design
KEYWORDS
Cognitive Abilities, Menu Selection, Metaphors, Spatial
Visualization Ability, User Interfaces, Visualization Techniques
PROJECT SUMMARY
The positive impact of computer-based technology varies in part as a
function
of interface design and the individual abilities of users. A model is
proposed
for how individual differences are expected to affect performance when
technology
is introduced. The primary cognitive factor driving differences in
performance
using computer-based technology is spatial visualization ability (SVA). Four
techniques for mitigating the negative impact of low spatial visualization are
discussed. The use of spatial metaphors and graphical user interfaces have
been
promising, but interface apparency, revealing hidden relationships and showing
contingencies, and interface manipulatability, allowing users to directly
manipulate objects and see intermediate steps, are most likely to benefit
individuals with low spatial visualization ability. Past research on the use
of
spatial metaphors and graphical user interfaces suggest positive benefits
across
all subject populations, but they do not mitigate the individual differences.
The current project explores the interface apparency and interface
manipulatability. Two studies are proposed in which the hidden
contingencies of
a hierarchical control structure are revealed through a dynamic graphical
screen
display. Several methods of showing the contingencies will be compared. Two
additional studies are proposed which allow users to manipulate objects
through
intermediate steps rather than having to infer or visualize those steps.
In all
four experiments spatial visualization ability will be assessed in
relationship
to the experimental conditions. The results of these experiments and the
design
concepts that are subsequently suggested by them will help to provide
interface
designers with graphical user interface (GUI) techniques that will provide
gateways through the SVA barrier. Interface apparency and manipulability will
help to off-load spatial processing from the user to the system and greatly
enhance performance.
PROJECT REFERENCES
Butler, S. A. (1990). The effect of method of instruction and spatial
visualization ability on the subsequent navigation of a hierarchical data
base.
(CAR-TR-488 and CS-TR-2398) Department of Psychology and the Human/ Computer
Interaction Laboratory, University of Maryland, College Park, MD.
Norman, K. L. (1994). Navigating the educational space with
HyperCourseware.
Hypermedia., 6, 35-60.
Norman, K. L. (1994). Spatial visualization: A gateway to
computer-based
technology. Journal of Special Education Technology, 12, 195-205.
Norman, K. L., and Butler, S. (1989b). Search by uncertainty: Menu
selection
by target probability. (CAR-TR-432 and CS-TR-2230). University of Maryland,
Center for Automation Research and the Department of Computer Science,
College
Park, MD.
Norman, K. L., and Singh, R. (1989). Expected performance at the
human/computer interface as a function of user proficiency and system
power.
Journal of Behavioral Decision Making, 2, 179-195.
AREA BACKGROUND
The design and evaluation of human/computer interfaces has become an
extremely important area in interacive systems. As the use of computers and
in
particular, graphical user interfaces have increased, the design of menus and
screen layout has become critical to the success of an application. Moreover,
human/computer interfaces are becoming more and more complex as they are
being
designed for larger and more extensive systems.
The usability of such
human/computer interfaces depends on how the cognitive abilities of the user
are either facilitated or stressed by the interface. Interface design must be
centered around our understanding of how the user
perceives the interface, comprehends its functions, and can solve problems
based on an understanding of how it works. An important cognitive ability
that
interacts with interface design is the user's spatial visualization ability,
the ability to manipulate spatial objects in memory and to keep track of
sequences of events.
The design of new human/computer interfaces should not only use graphics
to display icons, images, and menus, but also maps, sequences, and animation
to
aid the user in knowing where he or she is and knowing how to get to the next
desired step. Such systems will help to off-load the cognitively taxing
effort
of trying to keep track of the system's state in working memory and trying to
anticipate the next step by mental manipulations of spatial visualization.
AREA REFERENCES
Carroll, J. M., and Mack, R. L. (1985). Metaphor, computing systems, and
active learning. International Journal of Man-Machine Studies, 22, 39-57.
Mayer, R. E. (1989a). Teaching for thinking: Research on the
teachability
of thinking skills. In. I. S. Cohen (Ed.), The G. Stanley Hall Lecture
Series
(Vol. 9). Washington, DC: American Psychological Association.
Norman, K. L. (1991a). Models of the mind and machine: Information flow
and control between humans and computers. In M. C. Yovits (Ed.) Advances in
Computers, Vol. 32, pp. 201-254, New York: Academic Press
Norman, K. L. (1991b). The psychology of menu selection: Designing
cognitive control at the human/computer interface. Norwood, NJ: Ablex.
Vicente, K. J., Hayes, B. C., and Williges, R. C. (1987). Assaying and
isolating individual differences in searching a hierarchical file system.
Human Factors, 29, 349-359.
Yates, L. G. (1986) Effect of visualization training on spatial ability
test scores. Journal of mental imagery, 10, 81-92.
RELATED PROGRAM AREAS
Adaptive Human Interfaces, Intelligent Interactive Systems for Persons
with Diabilities, Virtual Environments
POTENTIAL RELATED PROJECTS
This project is related to other efforts of user interface design in which
graphic techniques are used. The question is to what extent emerging designs
solve cognitive problems for the user or create new ones. It is related to
other projects that deal with individual differences and attempt to compensate
for disabilities. Finally, the aspects of manipulation and spatial
visualization may relate to projects in virtual environments in which the
spatial manipulations can be seen rather than imagined.