he film critic gives ''The Lizzie McGuire Movie'' 2 1/2 stars. The film critic's two young daughters and their friends give it four stars. Now, who are you going to listen to: a professional with a college degree in cinema studies and decades in the field or a bunch of little kids?
Right: You're going to listen to the kids.
How could you not? The Disney Channel's ''Lizzie McGuire'' is that singular commodity, a 'tweener-grrl phenomenon that until now has barely registered on the radar screens of most adults. But the show, which airs every night at 7:30, has worked its way into the central nervous systems of millions of adolescent viewers, which means that now is the time for the evil geniuses at Disney to up the ante with a big-screen version and a pastel-pop tie-in soundtrack CD. Trust me, parents, you will be buying the soundtrack CD, and you'll be sick of it by the 43d time you hear it before dinner.
Still, there are worse addictions. The creation of TV writer-producer Terri Minsky, ''Lizzie McGuire'' has a down-to-earth sweetness that can be immensely appealing, and its view of middle school as seen from the middle social rungs is one that can hit empathetically home. Lizzie herself is played by Hilary Duff as a girl with idealized imperfections: She's smart but not brainy, pretty but not beautiful, athletic but disaster-prone. All the touchstones are in place: overprotective mom (Hallie Todd), spaced-out dad (Robert Carradine), brat brother with hair gel (Jake Thomas), best friends Miranda (Lalaine) and Gordo (Adam Lamberg), and teen-queen nemesis Kate (Ashlie Brillaut).
''The Lizzie McGuire Movie'' finds a way to pack them all off to Rome (except, mysteriously, Miranda, who's off on summer vacation when the film starts). Lizzie and Gordo are part of a school trip to the Eternal City; among the others coming along are snooty Kate and handsome-but-dim skateboarder Ethan (Clayton Snyder). Leading the excursion with ferocious military precision is Miss Ungermeyer (Alex Borstein), whose sardonic one-liners are, for mom and dad, all that keep the film from sliding into pink innocuousness.
Shortly after tossing the requisite coin into the Trevi Fountain, Lizzie meets Paolo (Yani Gellman), a sigh-guy young Italian pop star who insists she's a ringer for his singing partner, Isabella. (Isabella, when we finally meet her, is played by Duff in a brunette wig, which will come as a delightful surprise to the movie's target audience and no surprise at all to grown-ups weaned on the complex dualities of Samantha and Serena on ''Bewitched.'')
Paolo enlists Lizzie in a plan to impersonate the AWOL Isabella at an upcoming music awards show and wins her over with a lot of motor scooter tours of Rome. With a romantic style as silky as his shirts, he appears to be Signore Right. Gordo doesn't think so, though, and the film sympathetically watches as the little guy helps Lizzie get away from Miss Ungermeyer while wrestling with his newfound feelings toward his best bud.
Curiously, ''The Lizzie McGuire Movie'' goes against the grain of the TV show by turning the likably average Lizzie into the toast of Europe (shield your daughters' eyes from this next bit): She wins over Kate, makes friends with Isabella, and gets to sing a big pop-diva number while her family looks on with glowing approval.
The climax plays like Britney lite, in other words, and wide-eyed Duff (who seems much more at ease here than in ''Agent Cody Banks'') puts it over in a way that makes every girl in the audience feel like she's the star. So who am I to carp that the film trades in the amiable realism of the show for just another watered-down pop star fantasy?
Heck, it beats the Olsen twins. But not by much.