Before a reader draws me up short on Monday's link to an interactive map showing explosive growth of unemployment in the US, I should acknowledge the choropleth problem. James Fallows introduced the issue, and the word, in a blog post about the same map Tuesday. The problem is that geography does not equal population. A choropleth map depicting social trends (unemployment or election results) can mislead if its geographical units (states or provinces) vary widely in population. (The word derives from Greek terms for "area/region" + "multiply.") Fallows gives the example of the razor thin 2004 US presidential election, in which the...

04 August, 2010

Doug McCune uses San Francisco Police Dept. crime reports to map crime in that city as altitude. Narcotics: Prostitution: Various criminal activity: What would an altitude map of Halifax crime look like? Or better still, a North American altitude map of multiple sclerosis, a disease that concentrates in northern latitudes (with Nova Scotia a likely mountain range)? Any data-and-graphics-savvy medical researchers out there want to take this on? Hat tip: Flowing Data....

14 June, 2010