I guess it's not obvious to everyone.

[vakkotaur]

With this post, rillaspins reminded me of a bit about the water dispensers at work. We used to have the typical water cooler with the 5-gallon or so jug that would need replacing every day or two. Then a while back we got these gadgets that filter the city-supplied water into something that doesn't taste as miserable as city-supplied water.

These dispensers have three buttons. One button is blue. Two buttons are orange. It was obvious to everyone that the blue button resulted in cold water being dispensed. That was no problem. What was a surprise was how many people didn't realize that both orange buttons had to be pressed to get hot water. I can understand trying one button, then the other, then both, but it came as surprise that the simple safety feature had to be explained to some. It is a safety feature, too. The hot water is steaming hot - I don't need to bother microwaving the water for hot tea.

Comments

[timmowarner.livejournal.com]

Depending on what it looks like, I don't think I would think of pressing them both together...

Of course, maybe if I saw it the design would make it a bit more obvious.

[vakkotaur.livejournal.com]

Three buttons in a single column. Top button is blue. Bottom two are orange. They might be closer together than the top orange is to the blue, but I'm not sure just now.

[timmowarner.livejournal.com]

I think I'd figure that out. Vertical is the key.

[foolscap001.livejournal.com]

Well... if you push the blue button and water comes out that's colder than room temperature, you have immediate feedback. If you have to push both orange buttons at once, pushing one doesn't do anything, so one could as easily infer that the dispenser is defective--the orange button doesn't work! Besides, the association between colors and temperature isn't obvious. (Sirius is hotter than a red giant, so shouldn't the blue button give hot water? Des Moines has an (in)famous weather beacon, with lights of different colors to indicate various changes (or lack thereof) in temperature. Red means a predicted increase in temperature, white a predicted decrease... but white hot is hotter than red hot, isn't it?)

I'd be highly surprised if that water dispenser isn't an example in one of Don Norman's books.

It's hard to believe that it would be any harder to stamp a cartoon of fire by the hot water button and a snowflake by the cold water button than to use different colors, and it would be far more obvious... unless, I suppose, you live in the desert and have never seen snow.

[kinkyturtle.livejournal.com]

I don't think I would have figured that out. Are the buttons labeled at all? Any instructions?

[vakkotaur.livejournal.com]

I just looked at the thing. There is a label COLD above the blue button and a label HOT between the orange buttons.

[vakkotaur.livejournal.com]

As I related to kinkyturtle below, there is a label COLD above the blue button and a label HOT between the orange buttons, so rather doubt it'd fit into Mr. Norman's books that well.

I suppose I might have some advantage from having worked in and been around some industrial settings where the "must push two buttons to do something" bit is a common safety design. While I've not used industrial paper cutters, they seem to be the ideal example. For a single operator to start the cut, two buttons that cannot be reached with one hand alone must be pressed. This keeps hands well away from the cutting area when the thing is activated.