Arlington high school students who have three unexcused absences in one nine-week grading period will receive a failing grade of E in the course for that period under a policy the School Board approved last night in an effort to stem excessive absences.

Under the previous policy, students with four unexcused absences in a semester course, or eight in a full-year course, automatically lost credit for that course.

Many teachers and principals said that policy failed to provide incentive for students to attend class; students who accumulated four absences and lost credit early in the semester, they argued, had no reason to return to the course.

Under the new policy, students who fail one quarter due to unexcused absences will have incentive to raise their grade in subsequent quarters.

The board, in a 5-to-0 vote approving the new policy, also stiffened the penalty for tardiness. Three instances of unexcused tardiness in one grading period will be considered one absence; thus, a student would receive an E after being tardy nine times.

Superintendent Arthur W. Gosling stressed that the policy is not just an attempt to establish the number of unexcused absences that will result in a failing grade.

"I think the point of this policy is not to try to define so rigidly what the penalties are," he said. "The point is, when do we need to intervene so we get the kids back in class?"

In other action, the Board approved, by a 4-to-1 vote, a pilot program to put guidance counselors in the elementary schools. At Gosling's recommendation, the board approved the $159,500 program, funding the equivalent of six full-time staff positions, to try various models for elementary counseling.

Margaret A. Bocek cast the only vote against the proposal, arguing that there was no real need for an elementary guidance program and that such counseling might improperly delve into matters of family privacy.