August 3, 2007, 9:47 am
Are Pixels Better Than Piecharts?
By Lisa Agustin
“The Way We Live Now: Eternity for Atheists” in last Sunday’s New York Times Magazine included an infographic illustrating what Americans believe will happen to them after they die. Is this just a trendy twist on the piechart, or are we meant to glean more information from this technique? Presumably the main advantage of the pixel view is that each square represents a known quantity with which the viewer can estimate the actual number of people. A good idea, except there’s no key telling us what a pixel represents (or even a total number of people surveyed so we can extrapolate numbers ourselves). And what does the white rectangle in the middle represent — agnostics? The brightness of this shape makes me focus on it, rather than the data surrounding it.
I’ve seen these in Wired Magazine, too. It has to be some trendy design thing. It’s more visually precise than a pie chart, because you can count blocks, and the units (1 block = 1 percent) are clean.
But it’s a terrible design. The response values are in four different places. (And as you note, one section isn’t even labeled.)
More importantly, we have a harder time interpreting area than we do length. (Same problem that pie charts have.) I look at the “U” shaped figure representing 24%. It looks like it’s three times bigger than the 10% respone along the top line of the chart.
In fact, this graphic would have expressed more simply and usefully as a 2×5 table.
Posted by EB on August 3, 2007 at 9:50 pm
The square pie chart gets short shrift on the Economist’s Free Exchange blog:
Colour me sceptical; the benefit of round pie charts is that all points are equidistant from the center, so there’s nothing particularly implied by placement of each pie slice.
Healy points out that the square pie chart is not a “mosaic chart” which it superficially resembles. To explain mosaic charts, Healy links here (pdf).
Finally, several of Healy’s commenters assert that the chart is a sight gag. The white square is the door into the afterlife with the data arranged accordingly. It’s supposed to be distracting (as your life passes before your eyes…).
Posted by Henry Woodbury on August 5, 2007 at 9:00 pm