‘Dark Knight’ Will Redefine The Joker, Harry Potter Will Spend ‘Half-Blood Prince’ Reading And More Premature Movie Reviews

We grade this summer's surefire blockbusters based on photos, trailers and other flimsy evidence.

My mother always warned me about generalizing — about taking a small sample size and extrapolating it to fit an entire subject. You’ve heard the maxim too: “Don’t judge a book its cover.”

Whatever.

Look, I don’t need to taste the entire ocean to know it’s gonna be salty. And I sure as heck don’t need to see an entire movie before I can pass judgment on how good it’s going to be. That, dear friends and neighbors, is what trailers and photos are for.

With that in mind, we took a look at all the prerelease publicity for some of the year’s biggest movies to see what they have in store.

“Harry Potter and the Half-Blood Prince”

What We’ve Seen: Two photos from the set: one of Daniel Radcliffe looking pensive, the other of the trio in the Gryffindor Common Room, reading a newspaper.

What It Means: Unlike earlier Potter films, which went the unconventional route by pitting Harry against exciting beasties like dragons and thestrals and hippogriffs, “Half-Blood Prince” sees him face his greatest foe of all … homework! Despite Radcliffe’s claims to the contrary, based on prerelease publicity for the film, I feel confident in saying that 100 percent of this flick will be Harry reading.

Grade: F

“Indiana Jones and the Kingdom of the Crystal Skull”

What We’ve Seen: Several photos, one that’s notably of Indy atop a box of crates that appear to be in the warehouse from “Raiders of the Lost Ark,” and a trailer , half of which is clips from the previous three films.

What It Means: Since so much of what we’ve seen has been a deliberate throwback to the earlier films, I feel confident in saying that “Crystal Skulls” will be exactly like the combined experience of watching all three previous films back to back. That means it will be 33 percent awesome, 33 percent not as good, and 33 percent funny and invigorating — but also eerily similar to the first 33 percent.

Grade: C+

“The Incredible Hulk”

What We’ve Seen: Early pictures focused on Bruce Banner (Ed Norton) sitting in a medical chair or looking at his mutated blood. Angsty! The trailer, which we went over shot-by shot , mostly follows Banner as he deals with his “incredible” problem. This is punctuated by roughly 15 seconds of violence and mayhem as Hulk and the Abomination (Tim Roth) go at it in Harlem.

What It Means: By a complicated mathematical formula it took us three years of doctoral study to master, I feel confident in saying that the smash-to-angst ratio of “The Incredible Hulk” will be 1:4. This is much higher than the Ang Lee version but still not high enough to give a full endorsement — and nowhere near the legendary smash-to-angst ratio of my 7-year-old nephew.

Grade: B

“Iron Man”

What We’ve Seen: The first trailer , which essentially gives the whole plot of the movie away in two minutes.

What It Means: No, really, I feel confident in saying that it gives away the whole movie. Watch. Act One: Tony Stark goes to the Middle East to showcase new weaponry, gets captured, builds a suit and escapes. Act Two: Stark refines his suit as he comes to accept the responsibilities of being a hero. Meanwhile, Obediah Stane (Jeff Bridges) is up to no good. Act Three: Stark battles Iron Monger, gets the girl, gives a press conference.

Grade: B+

“The Dark Knight”

What We’ve Seen: The biggest viral campaign in movie history, with dozens of Web sites, scavenger hunts, phone calls and e-mails — all culminating in the most badass summer-movie trailer .

What It Means: Based on the film’s advertisements, Heath Ledger will give the singularly best comic book performance of all time, defining how we view the Joker from here on out. More than “Brokeback Mountain,” it will be his lasting legacy. The Joker himself, however, will defy categorization. He will spend 80 percent of the movie taunting Batman and the other 20 percent driving a semi that ultimately flips over. Harvey Dent will then call me at home.

Grade: A

For breaking news, celebrity columns, humor and more — updated around the clock — visit MTVMoviesBlog.com.