I was sent this chart recently:
Fundamentally this chart shows what it sets out to - the breakdown of grades A* - C across the years 2008 to 2014. But it could do with some Excel-fu:
- Remove the gridlines
- No 3D
- Tidy the axes labels - "Year" on x-axis is superfluous for example - and "Grade distribution" doesn't quite describe things.
- Tidied the legend (removed D / E as they are both 0)
As with most charts displayed on school websites, I'm left wondering "what the purpose of the visualisation is" - I suppose as a prospective parent, it's to show "how good the school is" - and I wonder if the chart, in the current form allows that judgement?
Instead of displaying the data as stacked bar charts with the columns as years, we can split the grades out and display each grade as a separate panel:
With such a panel chart, I can see that:
- The three year trend for A* grades is down
- A's are about the same
- B and C grades have risen year on year
- The fact that the majority of students get A* and A grades can be seen
Call to action
- Don't use 3D on charts
- Consider what you actually want to highlight - and ask yourself "does my chart actually show this"