A friend just pointed me to this wonderful 1993 paper by Bruce Tognazzini on applying principles of stage magic to user interface design.
As it happens, I’m in the midst of designing a novel kind of user interface that makes extensive use of “magic”. That is, it relies on the person who sees the interface buying into a consistent pseudo-reality that is quite different from the actual computation going on under the hood.
Needless to say, I found Tognazzini’s paper very relevant. In fact, he mentions a classic book on stage magic — “Magic and Showmanship, A Handbookfor Conjurers,” by Henning Nelms — which I immediately ordered on Amazon (I believe it is arriving tomorrow).
It’s a tricky space, because it all needs to consensual. You can’t simply lie to people, but you can create for them a fantasy that ultimately serves their purpose. After all, people don’t want or need to be reminded that Rick Blaine in “Casablanca” is really Humphrey Bogart, reciting words written by various other people.
Rather, viewers can only go on the deep psychological journey the film offers if they accept Bogie as Rick, and Ingrid Bergman as Ilsa Lund. In this case, truth can be received only through fiction.
In a sense, everything we do with computers exists within an analogous illusion. At bottom, the binary logic by which computers work is vastly user-unfriendly. The fantasy offered by the computer/user interface is not merely desirable, but necessary.
So what is the right level of acceptable magic in computer/human interfaces? Maybe the only way to answer this question is to try out your tricks on an actual audience. That may be the only way to understand when they feel lied to, and when they appreciate the rabbit coming out of the hat.