A nice post by Dan Lockton about the opposite of promoting ideal behavior in an interface: preventing errors from happening in the first place.

It’s often the view on influencing user behaviour found in health & safety-related design, medical device design and manufacturing engineering (as poka-yoke): where, as far as possible, one really doesn’t want errors to occur at all (Shingo’s zero defects). Learning through trial-and-error exploration of the interface might be great for, say, Kai’s Power Tools, but a bad idea for a dialysis machine or the control room of a nuclear power station.

+1 for the design patters, +5 for the Kai’s Power Tools reference.