Adulterated education

A good teacher makes a great difference.  Reader Richard M drove this point home when he sent in a junk chart posing as educational material. The offending graphic is used by BBC's Skillswise website to teach "Handling data: Graphs and Charts".  Skillswise is an otherwise laudable effort to help adults "improve their basic skills in reading, writing and maths".

Even for pros, each question is a challenge.  Question 7 really requires a new pair of glasses.

The entire worksheet is located here.  The use of patterns for shading is especially disconcerting.  The graphic also lacks self-sufficiency as we have trouble comparing countries without referencing the underlying data.  As we discussed before, a good graphic is one in which graphical objects (bars, pies, dots, etc.) illuminate the underlying data; when all the data must be printed next to the objects, the graphic is most likely redundant.

Source: BBC Skillswise website.
 

Comments

[Jon Peltier]

Wow, what a poor set of tutorials. You've presented the worst of them here, but not the only inappropriate one.

Their temperature by day chart challenges the eye with excessive gridlines, and the text describes the data as continuous, even though it shows only one measurement per day.

[Chris Hibbert]

What restraint! You didn't even complain that they seem to be using a pie chart to compare independent data points. The chart about GP consultations should be a bar chart, since the point is to compare the countries side-by-side rather than to emphasize that they make up a single whole (they don't.)

[Xan Gregg]

It's easier to answer the questions once you realize the countries/wedges are ordered by size!

[zbicyclist]

More proof that just about the only chart more abused than the pie chart is the 3-D pie chart.

[Kaiser]

Chris - great catch. While I was obsessing with figuring out the sizes of the pieces, the biggest blunder was missed. A pie chart used to present data that aren't proportions.

[Doug]

My retirement plan website uses pretty much the same technique to show my current investments.

I've always thought the pie chart seemed so lonely and sad next to the key, which contains all the useful data anyway.

[Kaiser]

Doug: that's exactly what I call self-sufficiency on this blog. If all the data have to be shown anyway for the chart to make sense, then the chart is not self-sufficient, and thus redundant.