Ferris Bueller had nothing on this kid.

After missing several days at Mark Twain Intermediate School in Franconia, the boy was called to the office of administrator Stephen P. Wareham, who phoned the boy's mother to discuss her son's frequent absences.

"Oh, he's here at home, sick in bed," she quickly replied.

That was years ago, but Wareham likes to tell the story to illustrate what he and his counterparts across the country face in accomplishing a school's most basic task: getting students to show up.

Frustrated educators complain that it is a battle waged all too often without parents, who would seem to be their natural allies.

Now, as principal of West Potomac High School in the Route 1 corridor of Fairfax County, Wareham has helped devise an experimental attendance policy that has sparked protests as well as some positive results.

The new policy, enacted jointly at West Potomac and nearby Edison High School for the spring semester that ended last week, essentially removes parents' power to excuse their children's absences.

At both Edison and West Potomac, one out of every 10 students is not in class on any given day, somewhat worse than the county average of 7 percent.

"That impacts on test scores, that impacts on grades, that impacts on retention, that impacts on a lot of things," Wareham said.

Under the old policy that remains in effect at the county's 21 other high schools, students with more than three unexcused absences during a 45-day grading period are failed. An unlimited number of excused absences are allowed.

Under the new West Potomac-Edison system, students are failed after more than five absences and parents are not allowed to excuse any of them. Students can make up absences on Saturdays and appeals are granted for extenuating circumstances, such as long-term illnesses confirmed by a doctor.

Teachers and administrators rave about the new policy and point to some encouraging results.

According to attendance figures, the policy had its greatest success at the beginning. In February, absenteeism at West Potomac dropped to 6 percent, compared with 10 percent the year before, meaning 60 more students were in school each day. But by the end of the semester, as many failing students simply gave up, and attendance dropped to last year's level.

While in the past some students got away with missing as many as 25 days of the 45-day quarter, teachers said those same students missed only three to five days last semester -- and often earned better grades. At Edison, the number of students who failed because of absences dropped from 80 in the second quarter to 24 in the third quarter, when the policy took effect, said Principal Robert F. Clark.

"It eliminated a lot of the frivolous absences, {such as} 'I'm going over to the mall and buy new clothes instead of going to school,' " said Roger Bolland, chairman of the science department at West Potomac.

But while teachers gush, some students say the policy is unfair.

With no excuses allowed for minor illnesses such as the flu, students say they went to school even if they should have stayed in bed to recover. "There are all these kids who come to school sick now and everybody walks around like zombies," said Allison Escherich, who graduated from West Potomac last week.

Students who remained healthy sometimes looked at the five permitted absences as a license to skip school. Some even wrote schedules of planned absences.

At West Potomac, two dozen students held a sit-in at the beginning of the semester to protest, but some changed their minds as time passed.

"A lot of people disliked it until they really found out what it was," said Ben Thrift, 15, a sophomore at Edison.

One of the policy's strongest champions is Christine Beal, the attendance officer at West Potomac.

After four years on the job, Beal has many horror stories of parents covering for their children. Some parents called at the end of the grading period asking for the dates their children were absent so they could write blanket notes excusing all of them.

"It was like there was a big cookie jar on the counter full of notes to pull out," she said.

Other schools have tried methods similar to the new policy.

T.C. Williams High School in Alexandria, for instance, switched to such a system about 12 years ago. Although it produced results, Principal John Porter said he wants to reconsider the system because students have learned to work it to their advantage.