Usability and Credit-Card Readers
Sunday, February 28th, 2010I get annoyed by credit-card readers. You know, the kind used at gas pumps and ATMs. I always have to look at it and try to figure out which way I’m supposed to put my card in, because it differs from one to another. In order to do that, I have to look for the ubiquitous instructional diagram and try to match my card to the illustration, because there’s no perceived affordance on the device itself.
Okay, it’s not rocket science. It takes maybe 2-3 seconds, and a tiny bit of thought to figure out. BUT. But why should I have to spend this time and effort at all for something that really could be effortless?
It’s like the example of the doors that Don Norman covers extensively in The Design of Everyday Things. You shouldn’t need to label your doors with instructions — “Push”, “Pull” — because people should know this intuitively from the shapes of the handles. Likewise, you shouldn’t need to label your credit card readers with instructions, because people should know how to use them intuitively.
There are two ways to fix this.
One, build some sort of affordance into credit card readers that only lets you put your card in one way, and makes it visually obvious what that way is. Since credit cards are basically featureless rectangles with no built-in directionality, this would be difficult.
Two, put magnetic strip readers on both sides, so that it doesn’t matter which way you put in your card. The existing affordance — a flat slot indicating where you put the card — is sufficient, and no further instruction is required, because it just works. I think this would be the best way to go, unless there’s some technical reason preventing it that I don’t know about.
The larger moral is that simple things we use everyday should “just work”, and if you’re constantly having to provide instructions on how to use something, that probably means that it’s annoying people.
Don’t annoy people. Practice good design. 
