I do agree that merits of a graph should not be judged by the audience’s ability to understand it without instruction.

My only feeble push-back is that the corporate environment doesn’t allow for luxuries such as traing and think-time.

As I ponder your remarks, it occurs to me that in 5 years, this conversation will be moot. With the adoption of bullet graphs in a myriad of software (future versions of Xcelsius and Excel being the big ones in my world) , a large majority of business users will have enough exposure as to make them second nature.

Think of all the money you could have made if you had not given the design away. I guess the joke’s on you Mr. “well-thought-out remarks”

I’ve introduced the bullet graph to many individuals and groups over the last few years. What I’ve found is that it takes less than a minute to teach people how to read it. It takes a great deal more time to teach people how to read other useful forms of data display, such as box plots and scatter plots, but it’s worth the time when the graph can tell powerful stories. When Hans Rosling of GapMinder presents information to audiences throughout the world using an animated bubble chart, even people who might ordinarily run from scatter plots or bubble charts in horror become captivated because Rosling introduces the chart in a way that they can easily understand. The point that I’m trying to make is that the merits of a graph should not be judged by the audience’s ability to understand it without instruction. The first time William Playfair used a bar graph, he had to tell people how to read it. Merit ought to be judged by the graph’s ability to tell the story it is meant to tell–clearly, accurately, efficiently, and without undue effort by the viewer.

A series of background colors that vary by intensity from dark to light is an intuitive use of color for representing a quantitative or ordinal scale, such as poor, satisfactory, and good performance. People in countries that use red, yellow, and green traffic lights to convey these meanings don’t understand them because they are intuitive, but because they have learned these meanings. This took more effort to learn originally (although no one remembers the effort) than it takes to learn that the lighter the color is, the better the performance is.

The bullet graph was designed for a very specific purpose: to present a single measure of what’s going on, compared to something such as a target, within the context of qualitative states (for example, poor, satisfactory, and good performance). It was developed to present this information in a manner that allows people to scan a great deal of information on a dashboard to quickly get a sense of how things are going. The bullet graph is only one of many effective ways to display information on a dashboard. When other forms of display are better suited to the task, they should be used.

It’s been fun to observe the ways that the humble bullet graph has been successfully used to solve real problems and how it has evolved to solve additional problems that I hadn’t anticipated when I first introduced it. Discussions like the one we’re having here on this blog will help to make this happen. Discussions like this might also plant the seeds of entirely new forms of display that have yet to be developed.

Steve

This has definately opened up a few ideas for me.

That said, bullet graphs have a cooler name than sparklines.Try saying “I’m gonna pop a bullet graph in your ass” and you’ll hear what I mean.

If I had to choose between a big dial, and a bullet graph, then I’d choose the bullet graph.

On using multiple bullet graphs on one chart, when I asked Stephen Few about it he said “When all of the measures share the same quantitative scale and the same qualitative ranges (for example, the same ranges of good, satisfactory, and poor performance), there is no real reason to use bullet graphs. I think it would usually work best to use a single bar graph with continuous qualitative fill colors in the background. This would make it obvious that the measures belong together and can be compared in all respects.”

However, if the quantitive scales differ, then bullet graphs might be a good way to report. For example, in Few’s bullet graph design spec at http://www.perceptualedge.com/articles/misc/Bullet_Graph_Design_Spec.pdf you can see at the top of page 2, there’s 5 bullet graphs per example and each one has a different quantative scale (i.e. different target bands).

So using a solid band option wouldn’t work here.