The U.S. Census Bureau has a Data Visualization Gallery where they post weekly "explorations of Census data." Some of these strike me as unnecessary (does adding animation to the map of population density around Interstate 5 add any value to the data?), but strangely cool; (I will never be able to drive north from San Diego again without remembering this map!). At the very least, the site is a showcase for the data and (I hope) an inspiration to budding data visualizers!

Hat tip to LAist, a website about Los Angeles, that has a brief story (4 Cool Ways Of Visualizing Local Census Data) that links to some of their favorites that show how the population has been changing in Los Angeles and California relative to the rest of the country.

The 10 most segregated urban areas in America, By Daniel Denvir, Salon (Mar 29, 2011). "Slide show: The new census numbers provide a sobering reminder of how separate white and black America still are."

Decades after the end of Jim Crow, and three years after the election of America's first black president, the United States remains a profoundly segregated country.

That reality has been reinforced by the release of Census Bureau data last week that shows black and white Americans still tend to live in their own neighborhoods, often far apart from each other. Segregation itself, the decennial census report indicates, is only decreasing slowly, although the dividing lines are shifting as middle-income blacks, Latinos and Asians move to once all-white suburbs -- whereupon whites often move away, turning older suburbs into new, if less distressed, ghettos.

One great way to get your head around a large government dataset is to view it using Google Earth. I went on a hunt for the most interesting, striking and geography based government data sets currently available in the KML format used by Google Earth. There is a large gallery of tours and layers available from Google Earth's site, including some based on government data - but I wanted to look beyond them.

Here are eleven data sources (in no particular order) that have KML files ready and waiting for you to download. For some of these you will need to read the instructions associated with the KML to understand what you are looking at and what special features are enabled. Some have multiple datasets within a single KML file -- others include animations. Often when you open them in Google Earth they will start out with either a helpful note or a built in graphical key.

• USDA Forest Service: MODIS Active Fire Mapping Program: View fire detection data and incident information
• USGS Earthquake Hazards Program: real-time earthquake data (updated every 5 minutes!), geologic features and virtual tours of historic earthquakes.
• FEMA Flood Hazards: Stay Dry provides basic flood hazard map information from FEMA's National Flood Hazard Layer for specific addresses while NFHL (National Flood Hazard Layer) appears to be a more general application that displays flood hazard zones, floodways, base flood elevations, cross sections and coastal transects and much more.
• NASA: Goddard Scientific Visualization Studio: provides various visualization layers including Tectonic Plates Boundaries and African Fires during 2002. Dig through the various categories, there is a lot here.
• Nasa Jet Propulsion Laboratory OnEarth: multiple options are available for viewing daily updated views of earth from satellites. Very striking!
• gCensus: provides access to data from the 2000 US Census. The site lets you browse for various elements of data and generate a KML file you can then view via Google Earth.
• Air Quality Now: provides current and forcasted air quality conditions for locations across the USA. It is a product of a partnership of multiple US Government agencies.
• National Weather Service: has a full page of KML layers related to all aspects of weather - past, present and predicted.
• National Gallery of Art: Afghanistan Hidden Treasures from the National Museum: visit Aï Khanum, Tillya Tepe, and Begram—that and examine Afghan Treasures
• National Park Service: National Register of Historic Places: provides Google Earth layers per region of the USA that mark historic places.
• District of Columbia Data Catalog: provides a wide range of data about our nations capital. You must supply some simple data to identify yourself before downloading these KML files. This is just a taste of what various regional governments are providing. Give your home state, district or territory's website a look to see if you can find KML data available.

Have a favorite KML formatted government data set I missed? Please share it in the comments. I found many of these by starting in Goggle's US Government Search and searching for Google Earth.

This month, the Federal Government finally released their much anticipated data.gov website. The purpose of data.gov is to increase public access to machine readable data sets that are generated by the Federal Government.

Now that site has gone live, it is time for all of us to start digging into the data. Provided below is a collection of references and resources to serve as a short visualization primer for those interested in exploring the data sets that have been made available.

Resources:

• Chart Suggestions - A Thought Start - A basic flow chart like introduction on how to represent data visually.
• Visualizing Information for Advocacy: An Introduction to Information Design - a very small booklet that teaches the principles and techniques of information design
• Periodic Table of Visualization Methods - A collection of visualization methods
• Milestones in the History of Thematic Cartography, Statistical Graphics, and Data Visualization - A history of visualization
• Online Library of Information Visualization Environments - library of visualization environments
• Tufte Design Principles

Websites and Blogs:

• Flowing Data
• Information Aesthetics
• EagerEyes
• Visual Complexity
• Data Visualization
• Information Design

Tools:

• Many Eyes - the YouTube of visualizations
• Juice Analytics - Chart Chooser
• DabbleDB - power data manipulation tool
• R - open source free statistical computing software environment
• Tableau - commercial visualization software
• Wordle - creates word clouds

Books:

• Tufte, E., (1990). Envisioning Information. Cheshire: Graphics Press.
• Tufte, E., (2006). Beautiful Evidence. Cheshire: Graphics Press.
• Tufte, E., (1997). Visual Explanations. Cheshire: Graphics Press.
• Tufte, E., (2001). The Visual Display of Quantitative Information. Cheshire: Graphics Press.
• Visocky, J., & O'grady, K. (2008). The Information Design Handbook. City: How.
• Jacobson, R., (1999). Information Design. Cambridge: MIT Press.
• Few, S., (2004). Show Me the Numbers. City: Analytics Press.
• Ware, C., (2000). Information Visualization. San Francisco: Morgan Kaufman.
• Card, S., Shneiderman, B., & Mackinlay, J. (1999). Readings in Information Visualization. San Francisco: Morgan Kaufmann Publishers.