Data Viz Done Right

August 11, 2012

Why sort order is important in bar charts (Nielsen needs help again!)

2 comments

Nielsen is at it again.  It’s not a spiral chart this time, but the simplest of bar charts that they couldn’t get right.

It all begins with this headline: “Telecom Grows Global Ad Spend, Durables & Services Decline”

Followed by this chart:

Wait…where’s telecom?  Oh there it is, all the way at the bottom.  If it’s so important, why isn’t it at the top?  Because they sorted the chart alphabetically.  When emphasizing rank, never sort your categories alphabetically.

Next question, which sector was the 4th fastest grower?  I bet it’ll take you longer than it should to find out.

A few very small tweaks, that take all of 10 seconds, would have made their chart so much more effective.

  1. Sort the sectors descending by growth rate, i.e., winners at the top, losers at the bottom
  2. Color code the bars to complement the length of the bars, i.e., double emphasize the point
  3. Put the mark labels on the ends of the bars
  4. Update the title – They didn’t mention that distribution channels were the leaders.  Why not?  I don’t get it.

image

Which sector was the 6th fastest grower?  I bet it took you less than 2 seconds, certainly far less time than when the sectors are sorted alphabetically.

Now their story makes more sense.  If only they would give their work a bit of thought and put more pride into it.  Nielsen consistently looks like they’re slapping a bunch of stuff together so that they can publish quickly. I think it hurts their brand to produce the junk they do, especially given how little time it takes to do it well.

2 comments :

  1. But if I just wanted to know where one sector was, and had no idea how well it had been doing, how would I know where to look?

    If it's alphabetical then if I want to look up 'Durables' I look under 'D.' With yours I have to read the whole thing.

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  2. If the purpose is to simply be a list, then you wouldn't even need the chart, you could use a table instead.

    If you go back and read Nielsen's article, they refer to the ranking of the channels, which is why my version is sorted descending.

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