Probable

Monday, 23 August 1999
There is just one button at the elevator. As soon as I press the button it lights up. Going up or down is not even an option, simple enough.

The elevator arrives. The light goes off. The door opens. "Is this elevator going down?" The present passenger nods affirmatively. "If somebody is inside, it'll always go down, as it doesn't stop on it's way up with passengers." he elaborates. It takes some time to absorb this message.

Good for me that I'm descending, but what if I wanted go up? I would have joined the ride down for a detour first or wait for an empty elevator. What a hypothetical drivel this is, I never used the elevator to go further up. So, the elevator designer did think about it thoroughly.

"Possible" and "probable" are two different things. Yes, it is possible that I wanted to go up, yet it is not probable. The elevator designer has rightly prioritised "probable" above "possible" and with good results too.

  • Those who go up reach the correct floor without any redundant stop.
  • Those who go down may pick up an extra passenger, but most likely that passenger will join the ride down.
Well done. My compliments to Kone elevators (www.kone.com). The simple user interface is an additional advantage. No tiring nagging on all kinds of theoretical possible options. Just one button, that lights up when the elevator is on it's way. Simple, yet effective.

Don't put might on will (ercb/com/...). That is the principle for the success. It's from Alan Cooper's book About Face. That book is about GUI Design. Well, there isn't that much difference between an elevator and a window, is there? Wouldn't it be great if Kone made software?

Till next week!
Nut