The envelopes for the various Oscar awards were identical. The only difference between the envelopes was the text that indicates the award category. There was no other means of distinguishing (eg, colour, pattern) one envelope from another.

Other industries

Several industries have realised the problem with this approach, and in some ways what follows can be considered the beginnings of trying to design safe systems and minimise the chances of human error. In 1947, experimental psychologists Paul Fitts and Richard Jones adapted their laboratory techniques to study the problem of pilot error during World War II. The problem they faced was that pilots of one aircraft type frequently retracted the landing gear instead of the flaps after landing. This hardly ever occurred with other aircraft types. They noticed that the gear and flap controls could easily be confused. The nearly identical levers were located right next to each other in an obscure part of the cockpit.