Interactive federal statistical data on the Web using “nViZn” Jon Hurst*, Jürgen Symanzik, Lacey Gunter Utah State University * Web site:

Contents Background Information Our software Summary

Background > NSF Digital government Program Mission: “explore and develop new information technologies that will improve the way government serves the American people.” Digital Government Quality Graphics initiative: disseminate federal statistical data over the Internet in more usable and understandable forms. Resources:

Background > Micromaps Micromap is short for ‘linked micromap plot’. First presented in 1995 by Olsen, Carr, Courbois, and Pierson Help focus the viewers attention on the geographical significance of the data. Resources:

Example of a linked micromap plot

Background > Interactive micromaps on the Internet Planned, but never used, for the EPA Cumulative Exposure Project (CEP) USDA-National Agricultural Statistics Service uses ‘pseudo’ interactive micromaps The National Cancer Institute plans on using them in a web site to be made available this year.

Our Software > Overview Goals— Easy access Concise display of the CEP data Understandable to a non-statistical audience Solutions— Software accessible from the Internet “nViZn” SDK Interactive drilldown maps, micromaps, and tables

Our Software > “nViZn” A commercial, Java-based SDK for visualization and analytics Successor to the GPL Based on Wilkinson’s The Grammar of Graphics Includes libraries and sample code and applications Resources:

Our Software > Background Where possible, based on samples provided with “nViZn” Built on the previous code written by Lacey Jones Currently a prototype for an Internet application (such as would have been used by the EPA CEP) Final version?

Our Software > Interface Drilldown map Interactive tables Interactive micromaps Meta displays Live demo  (slides that follow are of images outlining the live demo)

Drilldown Map

Interactive table— Massachusetts benzene concentrations sorted by minimum values.

Interactive table— New York benzene concentrations sorted by mean values.

Micromap—New Mexico benzene concentrations sorted by median values.

Micromap— California lead concentrations sorted by mean values.

Comparisons between micromaps—Washington & Oregon median acrylic acid values.

Our Software > Implementation > Data Data is a duplicate of the EPA CEP data—hierarchical file structure 148 HAPs modeled for 60,000 census tracts according to 1990 data Organized by FIPS codes Outdated compared to databases ArcInfo gen files required for micromaps

Our Software > Implementation > “nViZn” “nViZn” libraries handle the data, analytics They also handle the creation of all graphics, and Interaction with the graphics A knowledge of Java is required Simple graphs are quick and easy Interactive applications are long and dirty

Our Software > Implementation > “nViZn” Code for using “nViZn” is usually concise The learning curve is steep

Our Software > Implementation > Summary About 2,000 lines of code About 200 hours for someone familiar with programming, but having never used Java or “nViZn”

Our Software > Missing features Database connectivity—“nViZn” libraries support database connections Applet enabled—currently it is a stand-alone application

Summary > “nViZn” Good communication with users Takes the dirty work out of graphics Very robust Huge potential for use with Federal statistical data, and especially geographically referenced data Training offered by SPSS

Summary > “nViZn” Poor documentation In some instances, no documentation or samples for features Desperately needs a manual Development time was unnecessarily long due to the lack of information

Summary Usability study needed: how do non-statisticians understand these displays