[BurritoAlPastor]

I work at a movie theater. We have four pairs of front doors, all of which open outwards. One pair has handles; these are the doors which should be used to enter the building. We sell tickets outside, and tear tickets at the door; if both these doors are open, people come in three or four at a time and we can't get to them and take their tickets. So, one of these two doors is always locked, and the entrance door which is not locked has a sign on it that says "Please use this door."

A nontrivial number of people will come up, read the sign, and promptly try to open the OTHER door, see that it's locked, and then walk away to try and find the "other door" - generally trying to push open the out doors. As it turns out, they all read the sign as saying "Please use other door".

(Occasionally they'll try to claim that the sign is wrong. There's a certain schadenfreude in the looks on their faces when I convince them to reread it more carefully.)

So, we removed the handle for the door that's always locked, and took down the "Please use this door" sign. Now people just walk along the out doors, pushing on them to try and find the one that'll open.

[tnicola]

Putting a 'Please use this door' on a door that is open is redundant. That is why people 'believed' that the sign said 'Please use other door.'

If you were in front of the door that is open, why say 'Please use this door.' They will. You don't have to say so. People generally do not walk up to the door they do not tend to use. Hence why they assumed that the sign said 'Please use other door', since that is 1) what is most often on the doors and 2) it's illogical to have a confirmatory sign on the open door.

[ramchip]

How about an 'entrance' sign on the door, and a red circle with a slash (no entry) on the other doors? Negatives tend to be less effective than positive statements, especially if the signs around are similar.