Suspension of disbelief, like misdirection, is one of those concepts in magic that is important, yet inaccurately described.
The phrase misdirection suggests that attention can be drawn away, when in actuality, all you can do is direct attention toward something. In a similar manner, you need to create belief, instead of negating disbelief.
The question then becomes, how do you establish credibility in magic? There are two major ways to establish credibility in your routines: externally and internally.
There are two basic ways to establish external credibility, with an authority on the topic, or what Chip and Dan Heath have dubbed an antiauthority. An authority, of course, is someone who is believable because of the knowledge they have and/or the respect they've generated in their field. By contrast, an antiauthority is someone who has suffered from their lack of knowledge in a particular field. For example, when it comes to the dangers of smoking, an authority might be someone like the Surgeon General, or a scientist who studies the effects of smoking, while an antiauthority might be someone like Barb Tarbox or Pam Laffin.
Antiauthorities aren't employed in magic very often (hmmm...any routine that did use an antiauthority would be different and original, wouldn't it?), but authorities are used quite often. Our perennial example, David Copperfield, employs credibility through authority in his imploding building escape:
In this clip, you see Copperfield establish credibility by having audience members inspect the steel plate, by referring to the 1st Security Safe Co., and through inspection by members of the Charlotte-Mecklenburg Police Department. If you watch the full episode, he actually goes even further by showing and mentioning the work of Controlled Demolition, Inc., and D. H. Griffin Wrecking in preparing the building for demolition.
External credibility can be great, but what about those of us who don't have the budget to employ authorities and/or antiauthorities? This is where internal credibility comes in handy.
First, there is the use of convincing details. Many of the the methods that magicians have developed to create internal credibility, as noted in the conviction section of Strong Magic, use this idea. There are many routines that employ the use of an apparent mistake to establish the credibility of the conditions in the routine.
Notice the mention in the outline of evoking a mental image. The use of concreteness, besides helping people understand and remember, can also help develop credibility. If you want to establish some fact or statistic to increase your credibility, make them accessible. In Strong Magic, Darwin Ortiz mentions a Peter Duffie routine involving two cards that are torn in half, and half of each card is then destroyed. The point that needs to be dramatized here is the uniqueness of each tear pattern. Darwin Ortiz' script for this point is wonderfully evocative: Did you ever see one of those old spy movies where the secret agent is given half of a torn dollar bill? Later, when he meets his contact, the contact produces the other half of the bill and they compare them to make sure they match. That way, the hero knows his contact isn't an impostor. This is because any time you tear any piece of paper, you create a jagged edge that is as unique as a fingerprint. You could sit in a room tearing playing cards eight hours a day for ten years and never succeed in getting two with identical edges.
While he could have said that the odds of getting an identical tear is 1 in 6 billion (or whatever the odds are), the vivid image of sitting in a room for an extremely long time tearing playing cards drives the point home much better, and establishes credibility. The reference to the uniqueness of a fingerprint also drives the point home. In my recent posts on visualizing pi, mathematical concepts, and scale, as well as the visualization section of my StumbleUpon blog, you can find plenty of inspiration for creating your own vivid images.
The next principle of internal credibility I'll discuss has long been used, but was named after a particular gentleman because he summed it up so perfectly. It's called the Sinatra Principle: If I can make it there, I'll make it anywhere. Jim Steinmeyer, for example, in his profile, establishes his credibility by mentioning his illusion design work for Doug Henning, David Copperfield, Siegfried and Roy, and Lance Burton. Right away, it's safe to assume that, if you want an original illusion designed for your show, he is qualified enough to handle the task.
The final principle, which is also used frequently in magic presentations, is that of testable claims. Use claims that the audience can check for themselves. In magic, this can be as simple as using a borrowed, shuffled deck for a routine. In Richiardi's sawing, as seen in my Unexpected post, he uses this idea by letting the spectators get a close look at the body after the sawing, as well as using real organs for the ...um... spillage.
To wrap this up, I'll show you a card routine. It's unusual in that it employs both internal and external credibility:
How many of the principles did you find? The most obvious are the use of the casino surveillance team (external credibility: authority), and the timing of the routine (internal credibility: testable credentials). There's also the mention of his world champion status (internal credibility: Sinatra principle), and the fact that he's performing in Las Vegas at Caesars Palace (external credibility: authority and internal credibility: Sinatra principle).
If you need to create belief in what you're doing, and agree that the conditions for your routine are fair, then establishing credibility is key. For more on the power of credible ideas, check out the credibility category of the Made To Stick blog.
Memorable Magic: Simplicity
Memorable Magic: The Unexpected
Memorable Magic: Concreteness