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One of the recurring themes in GIS education blogs, forums, listservs, conferences, and in our recent book The GIS Guide to Public Domain Data is the importance of paying attention to the characteristics of data so that correct interpretations of that data can be made when mapping that data. During some recent work with one of our favorite resources mentioned in the book, that of the Center for International Earth Science Information Network, (CIESIN), I examined a map showing the population density for central Europe (shown in image).ciesin_population_density_map-285x300.jpg
As I examined the map, population density for Germany seemed unnaturally higher than that of France. True, according to a variety of outside sources, Germany does have roughly twice the population density as does France (235 people per square kilometer for Germany versus 108 for France). But the map seemed to indicate that broad areas of Germany are even higher in density, approaching that of The Netherlands. Is this accurate?

Upon further investigation into the metadata, indeed, the resolution of the data set was to blame. CIESIN uses the highest resolution data available for generating maps like this, and the data they were able to obtain for France had a much higher resolution. The resolution is calculated as the square root of the land area divided by the number of administrative units. For Germany, it was 28, and for France, 4. The resulting population per administrative unit in 2000 was 184,000 for Germany versus only 2,000 for France. A-ha!

Close examination of the map prompted my initial concern: The areas mapped in Germany are much larger than in France. But the differences in data collection could not be confirmed until the metadata was examined. Fortunately, CIESIN does an extremely good job documenting their sources and methods. The user still needs to make it a point to read that documentation. But what should we do when working with sites that do not document their data well? In today’s world of a myriad of data, maps, and tools, it is more important than ever to have a good grounding in map interpretation and spatial analysis, but also to ask questions of the data you are using. How can we as the GIS education community foster this kind of questioning of data by our students?

- Joseph Kerski, Esri Education Manager
I created a lesson where students determine the optimal location for a bicycle and ski rental and sales shop using Esri’s Community Analyst software. The lesson begins with a scenario where the student’s task is to select the best site near one of the oldest and most beautiful rail-to-trail segments in the country—the Sparta-Elroy Trail in west-central Wisconsin. I have personally bicycled this trail, including its three famous railroad tunnels, and sometimes those personal connections to the area being studied make curriculum creation all the more enjoyable, and, I hope, valuable.

Students using the lesson examine local terrain, proximity to towns, the trail (shown by the thick green line in the image), interstate highways, campgrounds, and state parks, the area’s population, median income, amount of money spent by regional households on bicycling equipment in the past year, and the location of existing bicycle rental and sales shops. They also consider customers who would rent versus own the equipment, and consider how winter sports such as cross country skiing, snowshoeing, and snowmobiling would impact the shop’s year-round and overall viability.sparta_elroy_community_analyst_screenshot-300x220.jpg

I chose Esri’s Community Analyst platform for several reasons. The platform is cloud-based, and as no software is needed, accessing the toolkit is as easy as accessing a web browser and logging into Community Analyst. Some universities have access to this toolkit already, so check with your university. If the software is not part of your university license agreement, you can request a 30 day free trial. Better yet, ask your university Esri software point of contact to add Community Analyst in the future. The toolkit can easily create reports, thematic maps, 5-, 10-, and 15-minute drive time buffers around proposed locations, and export those maps and reports.

The software includes thousands of data variables, not only Census data, but thousands of consumer behavior and expenditure variables, plus thousands of business locations. I still feel like I’m in Willy Wonka’s candy shop when I’m using it because like many of you, I have gone the “long route” numerous times over the past 25 years, spending hours, days, and weeks formatting data from various sites to be able to get it to the point where I could analyze it. With Community Analyst, the data is at your fingertips, ready to be analyzed!

How might you use this lesson, or create a site selection lesson of your own using Community Analyst, to foster spatial thinking, business skills, and GIS skills?

- Joseph Kerski, Esri Education Manager

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