Thanks to a nice call-out post link on Flowing Data in my RSS feeds this morning, I found Naomi Robbins’ Effective Graphs Forbes blog, perused the archives a bit and came across her post on arrow charts.
She presented a nice comparison between (ugh) pie charts, arrow charts and slopegraphs. Sadly, both the NPR slopegraph and Peltier’s slopegraph included in the article committed some of the cardinal sins of slopegraphs I have pointed out previously. Let’s take a look (click on each graphic to make them bigger):
- Use of binning/rounding without annotation
- Use of binning/rounding but not to show rate of change
- Stacking labels (presenting rank where none exists)
More faithful representations would be explicit rounding/binning (to only show rate of change):
or the full scale version (warning: huge slopegraph) to accurately show the value differences and rate of change:
The data set is small, so transcription is not really be an issue, but here is is for you if you want to play with it some more.
This is definitely a case where her arrow charts are a solid alternative to slopegraphs, so definitely check out her post.
