Aligning the visual and the data
Dec 16, 2020
The Washington Post reported a surge in donations to the Democrats after the death of Justice Ruth Ginsberg (link). A secondary effect, perhaps unexpected, was that donors decided to spread the money around; the proportion of donors who gave to six or more candidates jumped to 65%, where normally it is at 5%.
The text tells us what to look for, and the axis labels are commendably restrained. The color scheme is also intuitive.
There is something frustrating about this chart, though. It's that the spike is shown upside down. The level that the arrow points at is 45%, which is the total of the blue columns. The visual suggests the proportion of multiple beneficiaries (2 or more) should be 55%. There is a divergence between what the visual is saying and what the data are saying. Whichever number is correct, the required proportion is the inverse of the level shown on the percentage axis!
This is the same chart flipped over.
Now, the number we need can be read off the vertical axis.
I also moved the color legend to the right side so that the entries can be printed vertically, in the same direction as the data. This is one of the unspoken rules of data visualization I featured in my feature for DataJournalism.com.
In the Trifecta Checkup (link), the issue is with the green arrow between the D corner and the V corner. The data and the visual are not in sync.
You can follow this conversation by subscribing to the comment feed for this post.