The Arlington County school board inaugurated the 1980s last week by taking a few more steps in the direction of "back to basics."

At its first meeting of the decade, the board adopted a stricter student rights and responsibilities policy and approved the expansion of Page Traditional School, an alternative elementary school which stresses homework, dress codes and classroom discipline.

Taken together, the actions are an indication that Arlington is following the national swing away from some of the more experimental concepts in education popular at the start of the last decade.

"All of those innovations were the result of turmoil in the last 60s . . and a tendency to capitulate to what students perceived to be relevant," said board member O. U. Johanse. "They have gradually run their course."

The student policy adopted is the second revision of a document drafted in 1970.Much of it is a compilation of existing state and federal laws dealing with such issues as student rights of free speech and assembly, privacy and record requests.

The major change involves stricter attendance requirements. This year students in grades 9 through 12 forfeit credit for semester-long courses after five unexcused absences. The new policy, which will go into effect next September, expands the guidelines on unexcused absences to include elementary and intermediate school students.

At the elementary level, parents are to be contacted after the first unexcused absence and called in for a conference after the second. At the intermediate level, if a student accumulates five unexcused absences a T for truancy will be added to the grade of each course affected. At all school levels, students forfeit daily class grades for individual absences.

Unexcused absences have dropped at county high schools this year as a result of the new attendance policy, officials report. But they admit the new plan is not without problems. After a student has passed the cut-off point for credit, there is no more incentnive to attend that class. There is also an extensive amount of paperwork required by the policy.

The vote to add a kindergarten and seventh grade to Page Traditional School was 4-to-0, with board member Torill B. Floyd abstaining. She worried that, in a time of declining enrollment, creating a new class of 54 students might precipitate an early review of some county intermediate schools for closing.

"We're only talking about 12 students from each intermediate school," said board member Mary Margaret Whipple. But Floyd countered that last month's decision to consider Woodmont Intermediate School for closing was based upon the school enrollment dropping by just two students below the 224 student minimum established by the board.

The board action represented the second expansion of Page school since it was established in 1978 as a "traditional" alternative for students countywide. A sixth grade was added at the beginning of this school year. Next September the school will include grades kindergarten through seven.

Parents and other supporters of Page argued at a public hearing last month that the addition of the extra grades was necessary for educational "continuity." Page principal Frank Miller testified that the 98 percent of the parents who responded to a questionnaire last spring graded Page as excellent or good. A similar questionnaire sent to parents throughout the county showed only 81 percent were as pleased with their schools.

Page parents have indicated they will ask the board next year to consider adding an eighth grade to the school. But board members have said there is not enough room in the school for another full grade. Another potential problem is that curriculum requirements for eighth graders demand a variety of courses not available at Page.

"When the request is made next year for the eighth grade," said Whipple, "it's going to be a knottier problem."