Or, boy I am I oblivious.

Eric Peterson lobbed this my way a week ago and I just noticed it a few days ago (I’ve been hard at work on a response).

His basic question, if I may restate it, is “What do I think about using a ‘tachometer‘ to display KPI data?”

The short answer is, I love to do this - when it’s practical.

If you work in Excel, it is often not practical because the level of initial work and maintenence needed to operate a custom chart element like this violates the efficiency rule (remember, that in order for reports to be truly effective, they need to be easily repeatable so that they can be delivered efficiently and on time). In other words, I’m lazy and it is, generally speaking, too much work for not enough return.

That being said, I’ve spent the past couple of days approximating the dashboard that Eric refers to (via Dashboard Spy and courtesy of Subaru) in Excel, to see if it could be done - with the proper wherewithal.

Here’s a screen grab of the finished product:

Ok, so it can be done.

Here’s a list of resources you’ll need to pull it off:

• Andy Pope’s Gauge Work Around
• John Peltier’s Speedometer Work Around
• Apps Pro X/Y Chart Labeler
• Excel Camera Tool

Scared yet?

Ok, here’s my file for the above picture, you’re welcome to try it out (no commercial use, please), but I make no warranty as to the accuracy or stability of it.

Long story short, custom dashboard elements like the above are cool, sexy and can effectively communicate important information such as KPIs, but hopefully you have a better platform than Excel to create them in (this is where something like Xcelsius becomes helpful).

The guys over at Juice Analytics are at it again.

It’s another one of those ‘doh!’ moments where I say: “Why didn’t I think of that?” Basically, using a simple function in Excel (Rept, aka repeat) which allows you to repeat any piece of text N number of times, you can create simple, in-cell horizontal bar charts. I’ll let you go read their post as they explain it quite well and thoroughly.

All I have to say is, no need to wait for Excel 2007 and their less than accurate in-cell gradients - you can be doing this right now and it’s not only a better solution but also is extremely reminiscent of a sparkline.

It’s Oh So Punny Post Title Day.
None the less, Stephen has started a series of posts under the title of ‘The Graph Hall of Shame’

You can e-mail your personal gems for nomination to sfew-at-perceptualedge-dot-com

If Stephen picks one of your submissions, we get the added bonus of he and other visualization aficianados commenting on all the issues and maybe even suggesting a tip or three to resolve those problems.

Don’t use ‘em…

…Unless you have multidimensional data that requires 3 points of definition (even then it’s a risky idea).

3-D charts create perspective by tricking the eyes and these tricks skew users’ perception of the data.

Even multidimensional data doesn’t necessarily need a psuedo-3D or 3D rendering. The archetype being Minard’s chart of Napoleon’s march on Moscow. Each point in the plot has at least four (x and y location on a 2-D plane, direction of travel, and size of the army) dimensions and some (the retreat) include time and temperature. No fancy 3-D here and yet, it’s probably the best chart ever made (I happen to whole heartedly agree with Tufte on this one).

It has been my experience that, especially in business, 3-D charts are a gimic - they offer a quick hit of supposed professionalism or ‘design esthetic’ to a chart. They are very tempting because the software authors put some more design work into them than they did the other chart types. But at what cost? If the slickly designed chart skews understanding, doesn’t that potentially lead to the wrong decision and the wrong action?

So watch out for 3-D charts, they don’t typically add any value or better portray the information you are trying to convey and, in the worst case, can be harmful to the decision-making process.

The other day, Dashboard Spy pointed out Dundas - a provider of Data Visualization solutions using .net and Flash.

I took a peek at their solution gallery and about the best thing I can say is that these are polished examples. Dundas obviously went to a great deal of trouble to develop examples that would appeal to a stereo-typical marketer (wow! wouldn’t these look great in a presentaton!).

But just because a report design is polished doesn’t mean that it’s any good at conveying information. Take for example their ‘3-D’ line chart. ‘3-D’ lines are a bad idea to begin with as the prespective tends to skew the data and makes understanding difficult, but the animation also distracts and slows down (literally because we have to wait for the data to load in) understanding. The one useful bit of information in the chart is the highlight on the month of July - except we don’t know why it is highlighted - what’s so important about July?

Here are a couple of tips:
1. Don’t use 3-D charts unless your data is three dimensional (has an x,y and z coordinate)
2. Provide context (specific chart title, x-axis and y-axis labels) even if you think the definition of the data is implicit or as in the above, it’s ‘dummy data’ - context supports understanding. Without context we’re left scratching our heads, wondering what to make of it.

Post Script: Dundas’ solutons may be wonderful (I wouldn’t know) but I think their pitch (e.g. their .NET Gallery) is not well targeted. Folks who are serious about visual reporting (and thus likely to convert for the right tool) probably won’t be any more fond of their examples than I was. Always put your best foot forward.