I posted the other day about data visualization tools, but even the best tools can’t save you if you’re clueless about visualization techniques. Most of this stuff isn’t web-specific, but I rant so frequently about this stuff to my classmates that I thought it’d be worthy of a post.

Charts!

Flowing Data recently challenged their readers to improve this chart:

What was the graph trying to show? It was trying to show party registration in California over the past five presidential elections. Did it succeed? No. It failed miserably; however, you did much better. Here are all the reworks.

My favorite rework tells the story far better:

More charts

The Gettysburg Powerpoint Presentation is absolutely priceless (quote from Norvig’s “making of” page):

I imagined what Abe Lincoln might have done if he had used PowerPoint rather than the power of oratory at Gettysburg. (I chose the Gettysburg speech because it was shorter than, say, the Martin Luther King “I have a dream” speech, and because I had an idea for turning “four score and seven years” into a gratuitous graph.)

Cartograms!

Le monde dans les yeux d’un rédac chef (The world in the eyes of an editor in chief) illustrates how news organizations cover the world disproportionately using one of my favorite visualization techniques, cartograms.

The cartograms below show the world through the eyes of editors-in-chief, in 2007. Countries swell as they receive more media attention; others shrink as we forget them.

Check out Worldmapper for lots more killer cartograms like this one:

Territory size shows the proportion of the world’s adherents to Islam living there.

And no cartogram rant would be complete without the fantastic 2004 election race map:

The (contiguous 48) states of the country are colored red or blue to indicate whether a majority of their voters voted for the Republican candidate (George W. Bush) or the Democratic candidate (John F. Kerry) respectively. The map gives the superficial impression that the “red states” dominate the country, since they cover far more area than the blue ones.

In this map, it appears that only a rather small area is taken up by true red counties, the rest being mostly shades of purple with patches of blue in the urban areas.

Further reading

If you’re digging this, and you’re not yet familiar with Edward Tufte’s work… now’s when your mind gets blown. His books, including the classic The Visual Display of Quantitative Information, are absolutely brilliant. I took one of his courses several years ago — it was mind elevating.

One example that Tufte uses has become, as far as I can tell, *the* visual representation of successful data visualization: Charles Minard’s graphic of Napoleon’s March. From the Wikipedia:

The graph displays several variables in a single two-dimensional image:

• the army’s location and direction, showing where units split off and rejoined
• the declining size of the army (note e.g. the crossing of the Berezina river on the retreat)
• the low temperatures during the retreat.

Brilliant.