Amy Sertl looks like a pro. She's only 10, but the strip of measuring tape dangling from her shoulders is not just a silly prop. Miss Sertl is part of the costuming team at the Vineyard Playhouse, and she's got that tape now cinched around Sarah Felder's cranium.

"That's 22 inches," she calls out.

"Do I get to wear a halo?" asks Miss Felder, 9, and prepping for a double role of mermaid and fairy.

For the past several weeks, fourth graders from the Tisbury School have descended on the Playhouse every Wednesday morning for what's called simply The Fourth Grade Theater Project.

On the surface, that title sounds as bland as oyster crackers, but this gig, now in its eighth year, is anything but bland. The goal is not just to have kids memorize lines from a play, paint a few sheets of cardboard sets and step out onstage.

Rather, this project immerses children in the world of the theatre and spares no details. That means handing kids responsibility for every facet of a production and pulling back the curtain on all the tricks of the trade. Tossed into the mix is a healthy dose of zaniness that reminds these youngsters that they're working with actors and artists, not teachers.

"It's chaotic and exciting," says M.J. Munafo, the artistic director of the Playhouse and a co-founder of the project. "It's different from school. We let them call us by our first names."

A far cry from the classroom, the fourth graders come piling into the big lobby at the Playhouse at 9 a.m. and are called into a circle for a game of "Yes!" A kind of theatrical calisthenics, the rules are simple. "One of us will make a suggestion, and then we do it," says Mrs. Munafo. "But only safe and fun suggestions."

Suddenly, a mass of kids turns into monkeys, then giant slugs slithering across the floor. Next suggestion is "Everybody introduce yourselves with a really fake British accent." For a moment, it looks like they are at the brink of mayhem, but they wind it down. Riders on the subway become whisperers in a library until the final cue is, "Let's all silently meditate."

This is week number five, and the preparations are in full swing. But they started from scratch way back in December. As with any play, the first step is writing, and the budding playwrights are a font of creativity.

"We teach them about plot, character and setting," says project co-founder Georgia Morris, who leads two classroom sessions with the fourth graders. "They come up with the elements and the most outrageous ideas, and characters like Poseidon and a chubby white mouse that don't fit together at all. We vote on which ones to keep."

Characters live and die under the editing process as the fourth graders craft their play. And Mrs. Morris, a writer and filmmaker who runs Galen Films with her husband, helps tie it all together, writing an outline and then a first draft, all the while seeking input from the kids. The same process is already under way with fourth graders in Oak Bluffs where Mrs. Munafo will guide the script writing.

With a final script in hand, it's time to break free of the classroom and head to the Playhouse. Getting to come to the theatre is a big part of the excitement for the fourth graders, says Mrs. Morris. It was back in 1993 that she first got the idea.

"The school was being renovated then so I called M.J. and said, ‘We've got to get these kids out of that building. Can we get these kids to the theatre?'" Her son, Sam, was a fourth-grader then and part of the first group.

Right away, both co-founders saw the project's potential. "We gave kids ownership of the play and the entire production," says Mrs. Morris.

They get to have a say in which jobs they take, filling out forms where they put down their top choices for acting. production, technical or artistic roles.

"Every time, there's some kid who writes on the ballot - actor, actor, actor. It will be the Casper Milktoast, the troublemaker or kid with a learning problem," says Mrs. Morris. "We always take that one, and they end up having a wildly opening-up experience, and it becomes a shock to everybody, including them."

For some, it marks the beginning of a commitment to the theatre. Sean George, now a junior at the high school who wants to pursue acting, was part of that first group in 1993. "It was a blast," he says. "And it's so appealing because it doesn't exclude anybody. Kids into visual arts can work on the sets. We were always learning about the process, and we just sucked up the knowledge."

Tisbury School teacher Robert Holt sees benefits of the project for all his students, not only because it caters to a range of interests but also because it doesn't just skim the surface. "It's an immersion in the theatre. In today's test-oriented society, that's almost passé because we have to move on and cover the next topic," he says. "This gives kids something more in-depth."

From the Playhouse's perspective, the experience sows the seeds for future theatregoers. "One of the ideas of this is to create an audience, one that knows what they're looking at," says Mrs. Morris. "A lot of them have never been to theatre before."

The Playhouse takes no chances on wasting this first exposure. The kids put on a total of six shows. With each class doing its own play, that's 12 plays in all. "They get to experience doing a run," says Mrs. Morris. By the last three shows, she adds, "they get to nail it."

Helping assure that the kids nail it is what seems like a battalion of adults, ready to guide and teach each team of fourth graders. Sally Cohn and Pam Benjamin worked closely with the artistic trio, designing backdrops and doling out cups of blue and green paint. Technical guru Ernie Iannacone spent a morning putting on a light-show meant to teach kids how lighting can set the mood of a play.

In their interactions with adults, the fourth graders are invited to make decisions and encouraged to take on the full weight of their responsibilities. The production team is dashing out the door to solicit ads for the program from downtown shopkeepers. Upstairs on the stage, actors sit in a circle, reading from their scripts and talking about their roles.

Two adults are also part of the cast, veteran Playhouse actors Christopher Brophy and Sheryl Dagostino. Mr. Brophy sets the tone for camaraderie and respect among the actors. "Everybody refrains from telling other actors how to say their lines or play their part," he says.

Their discussion centers on the personality of their characters. "Mine is very foolish, a big buffoon," says Mr. Brophy. "But deep-down, he's a good guy."

Then fourth-grader Andrew McElhinney reflects on his character. "Alex is the baby in the family," he says. Mr. Brophy asks him, "Do you get pushed around?"

Conversations are happening all over the Playhouse, and as the weeks go by, the talking takes on more urgency. This week, just days from the opening, Mrs. Munafo is doing a rundown with assistant stage manager Lisa Wilson. "Offstage, what props are preset?" she says.

The answer comes but it's expressed in theatre-lingo - off-left, down-right flat. The fourth graders have become insiders, fluent in a new language. Some can tell you what a leko is, or even a gobo and a pigtail. They've learned that downstage is closest to the audience because stages used to slope downwards.

The theatre is crackling with a kind of focused energy. Two boys are downstairs, giggling as they scrub paint drops off the floor. Upstairs, onstage, kids with pencils tucked behind their ears are going over lists while others are crinkling plastic gels as they sort by size and color.

Miss Felder says her Mom helped her to memorize lines by reading her the cues. And Miss Wilson, having satisfied Mrs. Munafo for the moment, says, "I didn't think being assistant stage manager would be this fun. I never realized how productive you have to be to put on a play."

Indeed, from the play's dialogue and props to ticket sales and spotlights, the kids here are in charge. As Mrs. Morris put it, "They'll all be capable of taking a bow that's worthy of the recognition they're getting."