The 1,002 students expected to attend school in Falls Church this year will find more computers in their classrooms Sept. 6, while the 14,455 students predicted for Arlington schools the same day will find tougher rules on absences and leaving campus during school hours.

Students in public and private schools and day-care centers throughout Northern Virginia will be affected by new state immunization guidelines this year. The new guidelines will particularly affect those attending schools in this area for the first time.

Under new state rules that became effective July 1, children entering day care or kindergarten through sixth grade for the first time in Virginia must have had a physical examination within the past 12 months and present a doctor's statement.

They also must show written proof of past immunizations for polio, measles, rubella, mumps, diphtheria, whooping cough and tetanus.

Students without documented evidence of immunizations may be allowed into schools once the series of shots is begun, however.

In the meantime, Arlington school officials are clamping down on attendance and tightening the rules for students who wish to eat lunch away from school.

Last spring, the Arlington School Board opted to cut the number of times a student can be absent from a class without loosing course credit.

Under the rules being instituted this school year, students will loose credit if they miss more than four classes in a course during a semester or more than eight during the year.

The system's previous policy allowed up to 10 unexcused absences in a class during the school year before any academic penalty was imposed.

Letters will be sent to parents notifying them when unexcused absences lead to a loss of credit, school system spokesman Dennis Smith said this week.

Under the "closed-campus" policy also approved by the board last spring, high school freshmen at the county's four senior highs will be prohibited from leaving the school grounds during the day.

Sophomores, juniors and seniors will be allowed to leave school grounds during lunch if they have the required parental permission, Smith said.

Students who have valid reasons for leaving school grounds, such as those involved in work-study or Career Center programs, will not be affected by the new rules.

The tighter policies are the result of criticism last year that the current rules permitting 10 unexcused absences and allowing students to leave school grounds at lunch contributed to juvenile crime and drug abuse.

A total ban on leaving school grounds during the day is to be phased in with incoming classes over the next four years.

In the meantime, sophomores, juniors and seniors who want to leave the grounds at lunch this year will have to have their parents go to the high schools to sign permission slips.

Student identification cards will then be issued at a cost of $2. Students will be required to show the picture ID cards to school monitors when leaving or entering the buildings during the day.

"The important thing is the parental permission," Smith explained. The School Board, Smith said, is trying to show leaving school for lunch is "a privilege, not a right."

In Falls Church, school officials say the biggest impact on education there this year will be the school system's purchase of new computer hardware and software.

When school started last year, the city's two elementary schools shared one microcomputer, according to William R. Thomas, head of elementary education in Falls Church. This year, at least 16 microcomputers will be available to students in the elementary grades, Thomas said last week.

The way the students use the computers also is being expanded, according to Jerry Bruns, pupil services director.

Last year, the thrust of the schools' new computer studies program was computer literacy--the teaching of the role, functions, parts and basic uses of the computer.

This year, however, students will be learning how to write their own computer programs through the use of the LOGO computer language. Students also will get more opportunities to practice math and writing skills on computers through new computer-assisted instruction programs, Thomas said.

In Arlington schools, where computer studies programs have been in place for the past few years, another new program of study is being added this year. Students interested in biology and veterinary science will for the first time be able to enroll in a year-long animal science program at the Arlington Schools Career Center.