Jarring the User

Have you ever reached for the hot water knob on a sink and either the handle turns the wrong way, or the cold and hot water knobs are backward?

It’s jarring.  

First, you freeze. Confused. It takes you a blip to get your bearing. You might even, just for a second, question yourself, “Am I doing this right?”

Then, you figure it out. Because it’s an easy problem to solve. Oh, turn the knob the other way. Or, the hot water must be on the right side. And, “No, I’m not doing it wrong. This thing is wrong.”

Is it wrong? What makes us think it’s wrong? What gives us the expectation of how it should work?

Intuition, of course. Built up through years of using sinks that conform to the US Plumbing standard of how a sink and its knobs should work. That standard has a whole history behind it that seeks to accommodate right-handed people. 

Sinks that don’t conform to this standard won’t land the plumber in jail, nor will some enforcement agency confiscate the contraband sink. 

But it’s jarring for the user.

If you’re making something for someone else, is that what you want? Possibly. That might be exactly what you’re going for. You need them to think differently or feel something.

But if not, the Law of Least Surprise is your friend. 

Know your user. Know how you want them to feel.

[P.S. I have a sink in my house on which the cold water knob spins backwards. After 23 years, it’s still jarring. I still spin it the wrong way every time. Every time. Why haven’t I changed it?]