Dashboard gauges were once the darling of the executive suite. Some designer took inspiration from a car dashboard and its gauges. A gauge is useful because it tells us how fast we are going or how much gas is in the tank. My newer model dashboard still has gauges but it also states how many miles until empty. That information is more useful than knowing how much gas is in the tank. It saves me the mental calculation because I understand miles and where I am going.
You do not see gauges as much these days. Visualization advisors complain the gauge uses too much space for the information given. Some even compare the gauge to the much disparaged pie chart. Eek, yes! Haters gonna hate.
But let’s open our minds. Just like with pie charts – do not toss gauges out of your designer toolbox! Instead, understand and use them when needed. I concede you may find limited circumstances for them. I also know that all toolboxes have items you do not use often. You do not throw out those tools.
Understanding the Dashboard Gauge Elements
There are several gauges available from SAS in their various applications [Visual Analytics|BI Dashboard| PROC GKPI]. These gauges are in five categories: Bullet, Thermostat, Slider, Dial, and Speedometer. You can make them horizontal or vertical.
Which ones do you think are easier to read and why?
Understanding a Gauge
The gauge has 3 main elements: measurement, target value, and the display rules. This gauge measures customer satisfaction where score of 1 to 5 is possible. The target is 4.25. The display rules control the section numbers and their color. The color gives you a clue – the pink is poor, yellow is getting by, and blue is within range. Here’s how a dashboard gauge works in SAS Visual Analytics.
Your Green Has Vanished My Dear
Are you curious about my color choices? I bet you expected something more like a Christmas tree exploding on the page. In Information Dashboard Design, Stephen Few suggested using soft colors for display. He also prefers to use blue for success. I agree and think it looks nicer. [And …. I don’t prefer green.]
Potentially your color choice can invite issues for those with red-green color blindness. Here’s an example of how a gauge would look if you were colorblind. I used the gauge with the number – I think it’s an alternate approach. But then …. do you really need a gauge if you display the number? [Thanks Coblis for helping create an example]
However, here’s the soft colors with the same test. It is more clear that blue is different color and not just a shaded color of the other one. The range numbers assist as well.
You be the Judge of the “Bad-iti-ness“
Let’s go over the criticisms and determine what is true. Maybe we can find some middle ground or at least form our own opinion.
Gauges Use Too Much Space
The round gauges do consume more space than the rectangular ones. When used in a grouping it does seem overwhelming. Here’s two examples where I display the same data with round and square gauges. When there are so many gauges, they both take up the same amount of space. [Note the data is from the San Francisco Airline Customer Satisfaction site.]
I made the page smaller so you can see the space usage of the entire section. While I care about space, the larger problem is that it is confusing when there are so many. I don’t know where to look or what to do. It seems like I’m spending a lot of time studying the images trying to decide where I need to look next.
Maybe data presented like this needs to be presented in a different way? For instance, if I convert the data into a table and use the Display Rules to add a thermometer for each measurement I can fit more on the page and in less space. I think it’s easier to read.
Gauges Provide Too Little Info for Space Used
A gauge tells you what is happening now and if it’s good or bad. It doesn’t seem like enough information. What do you do with that information? Let’s put the number in a table and display as text. The dial still takes too much room but maybe it provides a nicer way to consume the information.
When driving my car, the speedometer tells me how fast I’m going. I don’t need to know how fast I was going last week or even 5 minutes ago. The gas gauge tells me how much fuel I have. Again, it doesn’t matter how much gas I had at this same time last year. I only care about what is happening as I drive the car so I can react. I want to see where I am now.
Maybe it makes sense to use a gauge for some things rather than others. This gauge measures the Year To Date Sales against the goal. My thinking is that a sales manager is measuring sales on a daily or weekly basis. This person may be less concerned about where the team was last week, but where are they today. In this case, it helps the user know how close they are to the goal. The number doesn’t indicate that same urgency.
How Can You Better Use Dashboard Gauges?
When should you use gauges? It depends. What are you trying to do? Build a sales demo? Build a dashboard used 100s of times daily? Here’s some times when you can use them.
- A sales demo gets people excited about a product and helps them imagine how they could use the tool. It is a cheap trick. [But that is still a great 80s band!] It adds a nice graphical image particularly when you are just demonstrating a tool and not really trying to do anything.
- Maybe your boss or customer told you to do it.You can attempt to educate, but the message probably falls on deaf ears.
- You just like them and think it will work i your situation.
I started this post off by saying that you should not just ignore gauges or never use them. It is certainly what I think about pie charts. So I tried to create some examples that show them as a good a thoughtful application. It was hard. In my next post, I’ll show you some of the ideas and you can judge or hate on them.
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