Reader Alex L. submitted this chart showing the evolution of quality of life in Warwickshire in the U.K.
This wall of lights is drawing way too much power. Let's make a list of fixes:
- Stretch out the hemisphere, turning those arcs into horizontal lines
- Allow readers to read horizontally, rather than centrifugally (?)
- Align horizontally all of the labels for the quality of life indicators
- Allow readers to read indicator labels in one direction, rather than inside-out on the right hemisphere and outside-in on the left hemisphere
- Assume readers understand that the first year for which there is data is the "baseline year"
- Remove the distance between one data point and another, which makes unnecessary the white gridlines
- Use rectangles (rather than circles) as they can be packed more tightly
- Order the indicators in a meaningful way
Eventually this chart reveals itself as a heatmap:
The heatmap is much better. But the heatmap doesn't expose the trends clearly, especially the differences between indicators. The heatmap function (in R) has a built-in clustering method which automatically groups the indicators by similarity of trends. The color scheme should really be reversed since on this chart, red is good, and blue is bad; the default orientation of the column labels is also annoying. The bad indicators are clustered to the top, the good ones in the middle and the neutral ones at the bottom.
The next version uses the line chart, in a small-multiples setting. Now we have something to chew on.
Although not done here, we can order this set of charts using the clustering results from the heatmap.