O'Reilly logo

Usable Usability: Simple Steps for Making Stuff Better by Eric Reiss

Stay ahead with the world's most comprehensive technology and business learning platform.

With Safari, you learn the way you learn best. Get unlimited access to videos, live online training, learning paths, books, tutorials, and more.

Start Free Trial

No credit card required

Chapter Ten Predictable

For most people, predictability and consistency mean pretty much the same thing. Actually, I think there is a clear distinction: Consistent means something does the same thing each and every time; predictable means it does what you expect it to do. Let me give you a quick example.

In my house, all the electrical switches look alike and were approved by the same organization (Underwriter’s Laboratories—UL). That’s consistency. But when I travel somewhere I’ve never visited before, I expect to see switch-like objects next to doors that control the lights in a room—assuming there’s electricity. That’s predictability. The chances are really good these devices will either toggle in some manner or be a button that clicks on and off.1

As always, creating a proper shared reference lies at the heart of many predictability issues (see Chapter Seven). And retroductive inference also plays a huge role (see Chapters Eight and Nine—and stop skipping around).

1 Of course, there’s no guarantee that the switches are predictable as to either their function or location. See the “Tales from the Trenches” in Chapter Six. Or Google “Light switches - Mumbai, India” for a really funny article by “Steve.” Check out his other articles, too. He has a lot of great anecdotes about usability as it applies to service design.

When closed, this sink stopper looks like it ought to be operated by a lever or handle somewhere near the faucet. Only when I poked at it in desperation did ...

With Safari, you learn the way you learn best. Get unlimited access to videos, live online training, learning paths, books, interactive tutorials, and more.

Start Free Trial

No credit card required