“Mona Lisa Smile,” purportedly about a renegade liberal teacher at Wellesley College in 1953, centers more on character development than plot.

Julia Roberts as Katherine Watson is quickly thrown for a loop during her first lecture in art history at the college. Her students, each of whom has read and memorized the text book, shock the rookie teacher with their flippant command of the subject.

The somewhat frumpy Roberts (little makeup, mussed hair) is viewed as a West Coast bohemian by the strict, perfectly-groomed staff and students.

In a world where Roberts’ roommate Marcia Gay Harden, as Nancy Abbey, teaches speech, elocution and poise, and students want nothing more than to marry well, Roberts strives to engage the students’ minds and offer opportunities for them to think beyond the home.

Director Mike Newell gets the setting, costuming and some of the music right, but he seems torn between developing characters and making a point. The lack of authenticity works against the thrust of the story. Whereas the ensemble cast of 20-somethings playing 20-somethings is refreshing, scenes in the college dorm portray them as more 1990s girls than 1953 girls with their wild energy. Their drinking, smoking and physical play with one another are unrealistically liberal, as is the philandering Dominic West (Bill Dunbar). It is extremely unlikely a straight-lace institution such as Wellesley would have allowed a professor to seduce several students.

That said, the cast is incredible. Kirsten Dunst (“Spiderman,” “Crazy/Beautiful”) plays the delightfully wicked traditionalist, Betty Warren, who epitomizes the successful Wellesley student by marrying a lawyer before finishing college. She uses her wily talents in articles for the school newspaper to promote the staid fundamentals of tradition, ruining some relationships along the way.

The outrageous, lusty Maggie Gyllenhaal (“Confessions of a Dangerous Mind,” “Riding in Cars with Boys”) runs the emotional gambit as she follows her passions and interacts with the uptight Joan Brandwyn played by Julia Stiles (“The Bourne Identity,” “10 Things I Hate About You”), and the sweet, innocent Constance Baker portrayed by Ginnifer Goodwin (TV’s “Ed”).

Roberts is credible as she butts heads with the establishment and forays into the art world by taking her students to see a Jackson Pollock painting. She pays the price, but makes the point that anyone can decide what art is good and what is bad.

Rather than aspiring to be like the image in a girdle commercial which says “You couldn’t choose a better way to feel free,” Roberts encourages law school as a better choice for these brilliant young women.

Despite the miscues and the story that wanders into unnecessary relationships, the cast makes “Mona Lisa Smile” a delight to watch. Check your expectations at the door and sit back and enjoy.

Is it realistic? No.

Is it enjoyable? Yes.