Review: 'Bad Teacher' scrapes a passing grade

Cameron Diaz, Jason Segal and Justin Timberlake star in "Bad Teacher."

(CNN) -- Think back to your school days.
Remember that one teacher? The one who took a special interest in you, who made learning come to life and opened up avenues you never knew existed before?
Well, Miss Halsey (Cameron Diaz) is nothing like that.
Halsey got into the teaching racket for the long summer break, job security and lack of accountability ("all the right reasons," as she puts it), and she's not about to let any kid get in her way.
Her teaching methods consist of back-to-back movies -- she runs through the catalog of inspirational teacher flicks, from "Stand and Deliver" through "Dangerous Minds" and beyond -- while taking refuge in the drugs and booze she has stashed away in her desk. It's unconventional, but it works for her.
Still, Miss Halsey recognizes this isn't a long-term solution. What she really needs is a rich husband and a new pair of surgically enhanced breasts to get him.
Jake Kasdan's black comedy has attitude to spare -- but it's not so generous when it comes to laughs. The uneven, underdeveloped script by Gene Stupnitsky and Lee Eisenberg ("The Office" and "Year One") identifies a rich seam of mischief, a black sheep dressed as an authority figure, but not how to render bad taste palatable over the course of 90 minutes.
The sight of Cameron Diaz flipping a metaphorical finger at Michelle Pfeiffer, Edward James Olmos and company is certainly an eye-catching strategy, as well as a welcome reminder that she made her name by way of Jim Carrey and the Farrelly Brothers (in "The Mask" and "There's Something About Mary.")
Throwing herself into this rotten role model with the energy other actresses reserve for Oscar bait, Diaz is loose, fearless and terrifically sexy. Her Cheshire Cat smile threatens to eat up her entire face -- that is, when she isn't curled up on her desk nursing yet another hangover.
But unlike the sometimes equally misguided character Kristen Wiig plays in "Bridesmaids," or, for that matter, the irresponsible stand-in teacher Jack Black played in "School of Rock," Miss Halsey is too superficial to engage our interest or our sympathies for the duration. Even Billy Bob Thornton's Bad Santa wanted more than a boob job.
The same is true for most of the supporting characters, Miss Halsey's colleagues: Lucy Punch, Justin Timberlake, Phyllis Smith and John Michael Higgins give us several shades of square. They are intended to make Diaz's debauchery look hip (which it does). But while they each have their moments, the performances belong in a skit, not a feature film.
Only Jason Segal, as a spectacularly ill-equipped gym teacher, is permitted a hint of intelligence. The movie moves up a grade in the too-few scenes he's on screen.

All in all, it's a patchy effort from Jake Kasdan; never quite sharp or tight enough to see it over the rough plotting and thin characterization, but too ballsy to be boring. Like a naughty child, "Bad Teacher" wants attention but doesn't know why or what to do with it.