The wall of blinking lights
What went wrong and how?

Ornaments or fireworks for Christmas?

When I saw this chart:


I was wondering if the inspiration was these Christmas lighting ornaments,


(credit for the image: here)

or perhaps this beautiful piece of fireworks.


(credit for the image: here)


The chart was came from the same Warwickshire collection submitted by Alex L. (See the previous post here.)

This chart appeared to rank school districts by some arcane measure of academic performance based on public exam results (GCSE). It's anyone's guess what the color codes mean; I assume the intended readers of this chart would instinctively know the answer.

It also took me a while to figure out that the five groups on the left is the disguised legend, with the aggregate statistics. Perhaps the unusually big size threw me off.


This data set illustates the power of dot plots.


By sensibly grouping and sorting the data, one can easily understand both the average performance and the spread of performance, and both within each district group and across district groups.

If we can agree on where the acceptable standard is (say, 50% or more having "good GCSE"), then adding a vertical line to the above chart makes it that much more powerful.



Feed You can follow this conversation by subscribing to the comment feed for this post.

Peter Lauterbach

This chart does not seem to be a measure of school performance by district, but of towns where the student resides. See the note buried at the bottom:

"Based on residence, not school location"

So is the point to see if there is a correlation between where the student lives, and their academic performance, or what school they attend, and their academic performance. Sounds like some basic factor analysis should be done.


The colours are presumably the boroughs shown on the left hand side.

Dimiter Simov

Nice one. The chart becomes even better if we add some bars and text to the dots:


This post is really awesome and very helpful for me thank you for sharing this article and good job mate.

The comments to this entry are closed.