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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Last Updated: Oct. 13, 1998