GIS Research & Applications | GIS Database Development | Spatial Data Analysis | Geovisualization Tools Development | Communication of Georeferenced Statistics

Geovisualization Tools Development

As part of a broader program of data visualization research, NCI staff and their collaborators have developed a number of methods to better communicate cancer statistics visually, such as by maps and new graph designs. Examples of work in this area are:

1. Weighted Nonparametric Smoothing (Headbanging)
2. Tools implemented as ArcGIS Extensions
3. Conditioned choropleth maps
4. Linked micromap plot
5. Combining statistical clustering algorithms with new visualization tools

Weighted Nonparametric Smoothing (Headbanging)

"Head-banging" is a weighted two-dimensional median-based smoothing algorithm, developed to reveal underlying geographic patterns in data where the values to be smoothed do not have equal variances. The Head-Bang software helps users apply this algorithm to data.

Proportion of residents with no health insurance CDC Behavioral Risk Factor Surveillance System
Original data	Smoothed data
Data: Pickle & Su, American Journal of Preventive Medicine, 2002 Headbanging: Mungiole et al., Statistics in Medicine, 1999

Tools implemented as ArcGIS Extensions

Headbang smoothing: (download HeadBang for ArcMap™) SaTScan clustering: (download Cluster Analysis extension)

Utility to format SEER*Stat data for mapping: (download SEER*Stat Bridge) Color choices: (visit ColorBrewer) (download ColorTool extension)

Conditioned choropleth maps

• Decomposes a single choropleth map into strata according to 1 or 2 other factors
• Interactive tool -- users control classifications of mapped variable (red/gray/blue) & stratifiers by sliders

[D]
Carr, Wallin, and Carr, Statistics in Medicine 2000

Linked micromap plot

• Color links statistical graphs & maps
• Micromaps show spatial patterns
• Supports different glyphs & sorting

Carr, Wallin, and Carr, Statistics in Medicine 2000

Combining Statistical Clustering Algorithms with New Visualization Tools

Exploratory Spatio-Temporal Analysis Tool (ESTAT):

• Time trend plots of cancer rates
• Parallel coordinate plot of risk factors, confounders
• Scatter plots, maps
• Statistical summaries
• Supports linking, brushing, variable & option selection

Alan MacEachren, Penn State University (www.geovista.psu.edu)

GIS Research & Applications | GIS Database Development | Spatial Data Analysis | Geovisualization Tools Development | Communication of Georeferenced Statistics