If you’re even remotely familiar with slopegraphs, then you’ll recognize Tufte’s classic 1970-1979 GDP chart example (click for larger version): What you may not notice initially, however, is that Tufte — well — cheated. Yes, I said it. Cheated. I can show it by zooming into the “Belgium/Canada/Finland” grouping in the left column: The value “35.2”… Continue reading →