Alan MacEachren
302 Walker, Department of Geography
Penn State University
University Park, PA 16802
814-865-7491
Email: alan@essc.psu.edu
http://www.geog.psu.edu/MacEachren/MacEachrenHTML/MacEachrenTop.html
Here I provide two abstracts of recent and current research that
provide a sample of some of the perspectives that I’ll share in our
workshop. These abstracts represent just a small sampling of my research
perspective – that in general attempts to merge semiotic and cognitive
approaches to understanding spatial (geographic) representations and human
use of concrete spatial representations to prompt and modify their
cognitive representations of space. A much more detailed explication of
this representational perspective can be found in
How Maps Work: Representation, Visualization, and Design, Guilford
Press, 1995.
Abstract 1: This abstract summarizes a limited experimental
project
that I am working on with two graduate students. It is part of a larger
NSF-funded effort in which I play a minor role, Visualizing Earth
[http://visearth.ucsd.edu/]– the focus of which is research in cognition
and perception to better understand the developmental process students go
through as they learn to use visual georeferenced images and tools, and
how visualization tools can help students progress more rapidly and
effectively in learning about earth sciences.
Exploratory Data Analysis and map animation: Using temporal brushing
and focusing to facilitate learning about global weather
Mark Harrower, Amy Griffin, and Alan M. MacEachren
Department of Geography
Penn State University
University Park, PA 16802
LINEAR AND CYCLIC TEMPORAL LEGENDS: ASSESSING THE IMPACT OF LEGEND DESIGN
IN GEOGRAPHIC VISUALIZATION
Abstract: Understanding processes of the earth system demands a
sophisticated comprehension of the temporal as well as spatial aspects of
those processes; air temperature, for example, contains diurnal, weekly,
seasonal, and inter-annual patterns which are played out differentially
across the surface of the earth. Trying to understand the relationship
between multiple climate variables complicates this task further.
Representing such a complex spatio-temporal relationship is a significant
design challenge. We report here on the second stage of a project directed
toward developing a set of space-time visualization tools designed to
facilitate earth science learning. Our research has two primary goals. The
first is to integrate two exploratory data analysis methods (brushing and
focusing) with map animation to produce a manipulable dynamic
representation that facilitates a conceptualization of time as both linear
and cyclic. The second goal is to explore the use of these tools in a
Geographic Visualization (GVis) system which allows students to
conceptualize the spatial and temporal aspects of multivariate
continuously changing phenomena (specifically weather and climate) and to
develop hypotheses about those processes. To meet these goals, we have
built the GlobalWeatherAnalyzer (GWA) that facilitates examination of
three aspects of global weather (land temperature, ocean temperature, and
cloud cover) as they relate to one another in both time and space. Stage
one of this project involved building and assessing a prototype of the
GlobalWeatherAnalyzer. Assessment was carried out using a focus group
methodology. In the second stage of this research, reported here, we
assess the impact of different temporal legend styles (i.e. cyclic,
linear) on the user's problem conceptualization -- and thus on their
ability to develop an understanding of earth-climate processes. Rather
than focusing on performance differences resulting from the use of
different temporal legend styles, our interests lie in determining whether
these tools prompt different knowledge schemata, stimulate different
approaches to problem solving, and ultimately, if they lead to generation
of different hypotheses about the relationship between two climate
variables over both space and time. Legends in a dynamic learning
environment serve a dual role, as a key to the "sign-vehicles"
embedded in the display (i.e. to the symbols used to represent phenomena)
and as a control on parameters of those sign-vehicles (as what is often
called an "interactor"). In the research reported here, we
specifically investigate the impact on problem conceptualization (i.e. on
the knowledge schemata brought to bare on the problem), of providing two
temporal legends-interactors that represent and provide control over
linear and cyclic views of time. Participants in our study (students at
Penn State University) are given the task of describing the space-time
characteristics of two climate variables depicted on a dynamic map and
then generating hypotheses about the relationships, over time, of these
two variables. How participants use the GWA to explore data while
developing these descriptions and hypotheses is recorded. Analysis of the
descriptions and hypotheses generated is used to characterize
participant’s problem conceptualization. Comparison of descriptions and
hypotheses to patterns of system use allows us to characterize the impact
of each legend as both a key and a control.
Abstract 2: This abstract of a paper to be presented at the
spring
AAG meeting highlights a new project directed toward use of virtual
environment tools for visualization of georeferenced information and for
study of spatial cognition. This abstract emphasizes the former, but we
expect to extend the work to address a variety of cognitive issues.
Exploring the Potential of Immersive Virtual Environments for
Geographic Visualization
Alan M. MacEachren
Department of Geography and Center for Academic Computing
E-mail: maceachren@psu.edu
Raymon Masters
Center for Academic Computing
and
Daniel Haug
Department of Geography
Penn State University
University Park, PA 16802
As georeferenced data volumes continue to expand, scientific analysis and
policy decision making based upon these data become increasingly complex.
Advances in computer graphics technologies offer new methods for dealing
with that complexity. Our focus here is on the potential for integrating
geographic visualization (GVis) methods with technologies for immersive
virtual reality, for application to environmental science and policy
decision making. We propose a categorization of visualization environments
that emphasizes the extent to which these environments share
characteristics with real environments. This categorization is then
matched with four categories of visualization task (exploration, analysis,
synthesis, and presentation) and the advantages, disadvantages, and key
unanswered research questions related to each combination are noted. We
then present a case study in which we have applied both non-immersive and
immersive dynamic three-dimensional visualization tools to exploration and
analysis of spatiotemporal climate data. The immersive tool we are working
with is an ImmersaDesk from Pyramid Systems. Among the issues to be
considered as we compare use of the two environments are: (1)
applicability of each display form to visualization problems in which
representation is spatially iconic (i.e., geographic space is mapped to
display space) through increasingly abstract representations (i.e., with
display dimensions all used for non-geographic data dimensions); (2)
differences in interface control styles necessary for effective
interaction in the display environments, and (3) relative potential for
collaboration among individuals (locally and remotely). supported by:
U.S. Environmental Protection Agency & Penn State Center for Academic
Computing Keywords: geographic visualization, virtual reality,
environmental analysis
brief curriculum vitae
Alan M. MacEachren
Professor of Geography
Fellow, Center for Academic Computing, 1998-99
Department of Geography
Penn State University
Education
|
1979 |
Ph.D. |
|
Geography, University of Kansas |
|
1976 |
M.A. |
|
Geography, University of Kansas |
|
1974 |
B.A. |
|
Geography, Ohio University |
Professional Employment and Experience
|
1979-1983 |
Assistant Professor of Geography and Director of the
Department of Geography Cartography Laboratory, Virginia Polytechnic
Institute and State University |
|
1980-1983 |
Director of the Department of Geography Spatial Analysis
Laboratory, Virginia Polytechnic Institute and State University |
|
1983-1985 |
Assistant Professor of Geography, University of
Colorado-Boulder |
|
1985-1992 |
Associate Professor of Geography and Director, Deasy
GeoGraphics Laboratory, The Pennsylvania State University |
|
1992-present |
Professor of Geography, The Pennsylvania State
University |
Selected Honors
Distinguished Teaching Achievement Award - National Council for
Geographic Education, 1982.
American Congress on Surveying and Mapping - Andrew McNally Award for
Research in Cartography, 1983. For the article "Map Complexity:
Comparison and Measurement," American Cartographer, 9, 1, 1982, pp.
31-46.
American Congress on Surveying and Mapping - Andrew McNally Award for
Research in Cartography, 1988. For the article "Continuous Geographic
Surfaces: Sample Resolution, Intermediate Value Estimation Accuracy, and
Isometric Mapping." (with John V. Davidson) The American
Cartographer, 14(4):299-320 (1987).
First Place Award in the National Center for Geographic Information
and Analysis, Visualization of Data Quality Challenge for
project/paper "Visualizing the health of Chesapeake Bay: An uncertain
endeavor." (with Howard, D., von Wyss, M., Askov, D. and Taormino,
T.), GIS/LIS '93 Proceedings, Minneapolis, MN, 1993,
(449-458).
Wilson Research Award, College of Earth and Mineral Science, Penn
State University, 1998.
Selected Activities
Chair, International Cartographic Association Commission on
Visualization
Chair, U.S. National Committee for the International Cartographic
Association
Selected Publications
Five most closely related publications
MacEachren, A. M. (1992). Application of environmental learning theory to
spatial knowledge acquisition from maps. Annals of the Association of
American Geographers, 82(2): 245-274.
MacEachren, A. M. (1992). Learning Spatial Information from Maps: Can
Orientation Bias be Overcome?" Professional Geographer, 44(4):
431-443.
MacEachren, Alan M. (1995). How Maps Work: Representation,
Visualization and Design, New York: The Gilford Press.
MacEachren, Alan M. and the ICA Commission on Visualization (1998).
VISUALIZATION — Cartography for the 21st century," Proceedings of the
7th Annual Conference of Polish Spatial Information Assocaition, May
19-21, Warsaw, Poland (also available at: www.geog.psu.edu.ica ....)
MacEachren, Alan M., Boscoe, Francis, Haug, Daniel, and Pickle, Linda (in
press) Geographic Visualization: Designing Manipulable Maps for Exploring
Temporally Varying Georeferenced Statistics, Proceedings, IEEE
Information Visualization Symposium.
Five other significant publications
MacEachren, Alan M. and DiBiase, David (1991). Animated Maps of Aggregate
Data: Conceptual and Practical Problems, Cartography and Geographic
Information Systems, 18(4): 221-229.
MacEachren, A. M. (1994). Visualization in modern cartography: Setting the
Agenda. in MacEachren, A. M. and Taylor, D. R. F. (eds.) Visualization
in Modern Cartography. Oxford, UK, Pergamon. 1-12.
Howard, David and MacEachren, Alan M. (1996) Interface design for
geographic visualization: Tools for representing reliability,
Cartography and GIS, 1996, 23(2): 59-77.
Wilbanks, T., Adams, R., Clark, W., Church, M., deSouza, A., Gilmartin,
P., Graf, W., Harrington, J., Horn, S., Kates, R., MacEachren, A., Murphy,
A., Rushton, G., Sheppard, E., Turner, B., Willmott, C. (1997)
Rediscovering Geography: New Relevance for the New Century,
Washington, D. C.: National Academy of Science Press.
MacEachren, Alan M., Brewer, Cynthia and Pickle, Linda (in press)
Visualizing georeferenced data: representing reliability in health
statistics, Environment and Planning: A.
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