The very best [infographics] engender and facilitate an insight by visual means — allow us to grasp some relationship quickly and easily that otherwise would take many pages and illustrations and tables to convey. Insight seems to happen most often when data sets are crossed in the design of the piece — when we can quickly see the effects on something over time, for example, or view how factors like income, race, geography, or diet might affect other data. When that happens, there’s an instant “Aha!”…