Finding consensus among film critics seems hard enough (even Siskel and Ebert's thumbs pointed in opposite directions much of the time). Trying to get audiences to agree on what makes a good movie is another problem altogether. But when it comes to movie previews, Trailer Shop creative director Keith Gilman seems to put his finger on it when he says, "The trailer should always be better than the movie."

Said another way, the trailer should always make the movie look better than it actually is. And why not? In 2 1/2 minutes, the trailer could show the movie's best scene. Or great clips from a dozen different scenes. In the hands of expert editors with access to virtually any film score ever conducted (regardless of whether or not it's actually featured in the movie), there's no reason why the preview shouldn't make the film itself and all the performances within it look Oscar-worthy. In fact, beyond wooing audiences to the films themselves, many previews must also attract Academy attention to the films and performances that should earn their nominations come Oscar time.

But as virtually everyone has learned from personal experience, we regularly dismiss films on the grounds of their previews, only to have friends or critics inform us later that the movie turned out to be quite good. Though studios can produce opening-weekend television spots swiftly enough to include all that enthusiastic critical praise, trailers arrive in theaters months before critics see a film, often before the filmmakers have even assembled their final cut.

Unless distributors pick up a finished film (at film festivals like Cannes or Sundance, for instance), trailer editors must usually work without the support of positive accolades or awards, relying on the contents of the film itself to persuade wary audiences. But an expert preview editor can transform that 2 1/2-minute montage into a moving emotional experience, a resonant appeal that impresses audiences enough to coax those magic words from them: "Oh, yeah, I saw the preview for that. I heard it's supposed to be a good movie."

I tend to laugh when someone tells me they've heard a movie like Battlefield Earth was "supposed to bad," as though John Travolta and company intended for the movie to be a turkey. But what they're really saying is, from what they've seen and heard of the film (exposure that is often limited only to the trailer), they expect the film to be terrible. Getting butts in the seats may be a trailer's immediate purpose, but as Intralink's Anthony Goldschmidt explains, you go to the movies because "because you have an expectation of something intangible. You're not going to take anything away except some visceral, emotional, abstract experience. That is the responsibility of the audio/visual and print campaing, pure and simply." As we'll see in the next section, setting expectations is what the art of trailering is all about.

"The other thing to remember is that no bad advertisement ruined a good movie, and you can't make a good movie out of a bad picture by an advertisement," explains Donald Smolen, former Advertising Director for United Artists. True enough, but you can hypothetically make even the worst movie look great in its advertisements. How many times have you seen a preview that was better than the film itself?

The most spectacular movies (that is, movies with swooping camera movements, startling special effects, and roaring pyrotechnics) lend themselves to the most impressive trailers when the films themselves may not live up to the example. By the same token, previews for quality films that don't feature such dramatic set pieces or virtuoso showmanship come across at a disadvantage.

"No one sets out to make a movie that sucks," says DreamWorks' David Sameth. "If it's a failure, it's a failure somewhere along the line, but it was never intended that way. There's always something about a movie. There are movies that have good concepts but the execution didn't live up to what was expected, but maybe they're still movies that can open and find an audience anyway. The hardest is a great movie. American Beauty is a great example. How could you ever capture that movie? 'Bad movies' often have great lines, great head turns, everybody pitched at a high level. When you see the movie, it's ridiculous, but in the context of what we use, it's perfect."

Sameth's work on the campaign for Best Picture-winner American Beauty nicely illustrates the kind of approach trailer makers can use to convey a film's quality. Rather than bombarding audiences with story and spectacle, he opted for a more subdued, emotional appeal. The 3-minute trailer invites us to experience a very specific sensation, unfolding to the gentle wisps of a light aria. It takes a full minute establishing the film's atmosphere before taking it up a notch to the opening strains of The Who's "Teenage Wasteland." The trailer trusts its content, trying to capture some sense of how the movie will feel by revealing its characteristic pacing and look.

"There's very little plot in the American Beauty trailer. It was more like a feeling," Sameth says. "I'd see that in the middle of ten trailers, or it was the fifth trailer in eleven trailers, and to me, it just stood out. The rhythm of it was different. It just didn't seem like your standard trailer."

Much of the time, previews for quality movies opt to sell short the film's merits and concentrate on its most visually appealing aspects in hopes of attracting the largest possible audience. As a result, trailer houses all too often generate low-brow marketing pitches for high-brow films.

"You can make a really good film, but if it's about the wrong subject matter or about subject matter that people don't easily grasp, you'll flop," says Andrew Kuehn, president of Kaleidoscope and a 40-year veteran of the trailer business. "You can make a horrible film, but as long as it's categorically something the audience can deal with, you can do very well."

With good reason, disgruntled filmgoers frequently criticize movies for pandering to the teenage demographic, who are often blessed with more disposable income than any other group and therefore particularly attractive to studios. Even when the movies themselves aren't positioned towards teenagers, studios custom-tailor their trailers to appeal to these potential audiences.

For instance, after a disappointing first run, Paramount Classics theatrically re-released The Virgin Suicides under a new teenager-friendly marketing campaign that emphasized the stars' sex appeal. Where newspaper ads had initially focused on the critical merits of Sofia Coppolla's directorial debut, a new series of ads announced, "The year's most seductive movie is back by popular demand!" and flaunted quotations like, "Another lusty performance by Kirsten Dunst!" (San Francisco Examiner's Wesley Morris) and, "Josh Hartnett is funny and sexy!" (Vogue's Lisa Lowe).

Not only does this type of campaign ditch the opportunity to show audiences what a great movie The Virgin Suicides really is, but it also sets unreal expectations by misrepresenting the films, which brings us to our next point...