A few days before summer vacation began here last month, the playground at the Plummer-Motz Elementary School was filled with hordes of children swinging on tires, running each other ragged around a large dirt field, and darting in and out of a wooden castle called the "maze craze."

Jan Rankowski was not among them.

The 9-year-old, who learned five years ago that he has Asperger Syndrome, a neurological disorder similar to autism that causes him to misunderstand the social world, was climbing on a jungle gym in his front yard.

In November, after a string of complaints about what school officials said was aggressive and rude behavior, they banned Jan, who is home-schooled but spent recess with the other children, from the playground. The officials told the third-grader's parents not to bring him back until they allowed Jan to undergo an extensive evaluation known in educational parlance as a Functional Behavioral Assessment.

Jan's parents, Charles Rankowski and Gayle Fitzpatrick, sued the school, charging discrimination.

School officials say prohibiting Jan from going to the playground was necessary to protect the safety of the other 375 students. The dispute will be settled in a state court Aug. 20.

The dispute has emerged as a test case of how schools should treat students with Asperger Syndrome, which was designated a mental disorder by the American Psychiatric Association a decade ago. Advocacy groups said school systems are beginning to understand how students such as Jan adapt to classroom and schoolyard settings.

Michael John Carley, executive director of the New York-based Global and Regional Asperger Syndrome Partnership, who has seen news accounts of the case and spoken with Fitzpatrick but not school officials, said he was eagerly awaiting the court's decision and that "a misunderstanding of this child's disability could be to blame."

In addition to certain motor skill impairments and sensory complications, people with Asperger often have difficulty interpreting visual and spoken cues, though they often score highly on intelligence tests. Jan rarely, if ever, makes eye contact or responds to direct questions unless he was first addressed by name. But he also plays advanced computer games designed for adults, edits digital movies and speaks in complex, complete sentences that exhibit a large vocabulary.

Federal law mandates that children with developmental or other disabilities be educated in the "least restrictive environment." But the implications of that standard for children with Asperger Syndrome -- especially those who are home-schooled -- "is a brand new and developing area of law, with very little literature," said Fitzgerald and Rankowski's attorney, Ronald Coles.

Of the more than 78,000 children and young adults with autism in U.S. public schools, according to Department of Education data, those on the high-functioning end of the spectrum, such as those with Asperger Syndrome, are considered easier to "mainstream" or include in classes with non-disabled children, if the condition is diagnosed and properly addressed.

"For the most part the thinking is, yes, schools should make accommodations to address their learning needs," said Dorothy Lucci, a consultant who advises Massachusetts schools on inclusion issues for children with autism. "But it really varies depending on the individual child and the training of the teachers. Because the rules are so different, recess poses a particular challenge. Sometimes a child's confusion is misunderstood and interpreted as acting out."

Fitzpatrick said school officials were singling out her son and "treated my son differently from how they would have treated any other kid, and that is not okay. . . . All we want is for him to be back on that playground."

Jan's parents withdrew him from the Falmouth public schools in September, after a dispute over his education plan. At the time, the school agreed to allow Fitzpatrick to bring him to the playground for recess.

"Right away, we had reports of rock-throwing, of talking back to teachers, and of abusive language," school principal Barbara Powers said. "And Gayle [Fitzpatrick] said other children were bullying her son."

Powers assigned an educational technician to monitor Jan on the playground. According to notes compiled during the technician's initial briefing with school officials, she was instructed as follows: "Don't be lulled into [a] couple of weeks of calm. . . . [Don't] talk to mom. . . . Note who he plays with and what they do."

In subsequent weeks, school employees compiled 18 pages of notes and observations on Jan's behavior, with a daily accounting of incidents including Jan swearing at teachers and telling other kids "you don't have to listen" when scolded by school employees.

Powers said the school needed information about what was happening on the playground. Fitzpatrick said her son was "singled out for every little thing he did" and that responses caused by his condition were misinterpreted.

In November, school officials told Fitzpatrick to keep Jan from the playground unless a behavioral assessment was done. But Fitzpatrick continued to take Jan there until January, when she said a Falmouth police officer threatened to put her "in handcuffs." The family sued a month later.

School attorney Melissa A. Hewey said the call included no such threat.

School officials maintain they would like to see Jan return to the classroom to be educated. "This could be over tomorrow if they would be willing to allow" the behavioral assessment, Powers said. "Our sincere belief is that the best place for Jan is back in school."

Jan Rankowski, 9, has Asperger Syndrome, a neurological disorder that impairs social interaction. The dispute is a test case for how schools treat such students. Gayle Fitzpatrick and Charles Rankowski are suing the Falmouth, Maine, school district for banning their son Jan from the playground.