My first thought on seeing this week’s original was to try another way to show distribution. I turned to the boxplot, an under-appreciated chart. Steve Wexler, friend and co-author of The Big Book of Dashboards, really dislikes them, suggesting that laypeople don’t understand them. I disagree, and think that a lack of understanding is only caused by lack of exposure to them.
Hopefully my “How to read a boxplot” instructional image at the top helps those unfamiliar with them!
Boxplots pack a large amount of useful info:
- The whiskers spread to show outliers. Glasgow has a high SIMD score, but the data is very spread.
- Comparing location is much easier. Consider Glasgow/Dundee in the original and the boxplot:
It’s much easier to compare the two cities in the boxplot.
My boxplot still needs more work, which I would do with more time. I think it’s important to know how many data points are in each category. The Shetland Islands has a really narrow box, but that’s partly because there are only 7 items, compared to, say, 133 in Glasgow.