Norman doors, blame the design

A cognitive scientist gave his name, somewhat unwillingly, to a common frustration: the door you cannot figure out how to open. A door with a flat plate signals push. A door with a graspable handle signals pull, that is what handles are for. When a door has a handle but actually opens by pushing, people will grab and pull, fail, feel briefly stupid, and then push. And they will do it again next time, and so will nearly everyone else, forever, because the door is lying to them about how it works. No amount of adding a small push sign truly fixes it, the handle overrides the sign. His deeper point was about where we assign blame. When a single person makes an error, it might genuinely be the person. But when almost everyone makes the same error at the same spot, the fault is never the people but the design, which is quietly instructing them to fail.

When one person makes a mistake, it may be them, but when everyone makes the same mistake in the same place, the fault is in the design, not the people, because the design is silently telling them to do the wrong thing. This flips the usual instinct, which is to blame the person who erred. If a form is filled out wrong by almost everyone, a step is always skipped, a handoff repeatedly dropped, the problem is a badly designed system producing the errors on cue rather than a run of careless people. Before you blame people for a recurring mistake, look hard at whether the design is setting them up to make it, because a good design makes the right action obvious and a bad one manufactures failure no matter who is standing there.

The Design of Everyday Things

Donald Norman, 1988

The classic on why good design makes the right action obvious, and bad design blames people for its own faults.