This makes absolutely no sense.  These charts are an extreme waste of space when it comes to data density and they rarely contain anything that is actionable (for example, we are on pace for 105% of our site’s average visitors this month?… great). They fail and fail hard.

I have a personal vendetta against these charts because I spent an entire semester with them about ten years ago working for a grad student in the Laboratory for Automation Psychology and Decision Processes at the University of Maryland as an undergrad. I spent hours and hours sitting in usability labs testing other students’ ability to interpret gauges just like the ones available for use in our dashboards. I don’t remember the experimenter’s specific findings, but I do remember that the gauges didn’t work so well.

Over on Instant Cognition, Clint clearly agrees with me. In his article, A Gauge Chart that Works, he attempts to improve upon the gauge and succeeds. However, I still can’t think of an data application for it that wouldn’t have a more elegant solution.