A controversial grading policy that several teachers claimed would have sharply restricted their ability to fail students was rescinded by the Prince George's County School Board Tuesday night, one week before it was to have taken effect.

The board's action means that grades for secondary school students in the country will be determined by the same method used in past years - a "weighted" system in which the grade for the final quarter of course work is given more importance than the first quarter grade.

The new policy - which prompted scores of letters and telephone calls from teachers - would have averaged the grades from each quarter. The teachers complained that this method would have allowed students to ignore classwork in the final stages of a course and still pass.

In addition, teachers will again be allowed to automatially fail students who have eight unexcused absences in a semester, a practice the new policy would have prohibited.

"We are clearly saying to the public that the board does believe in the weighing of grades and that attendance is a very important part of educational discipline" said board chairman Norman Saunders.

Saunders led the movement to rescind the policy, which he had voted for last October. Although Saunders said pressure from teachers was not an important factor in his decision, he would not explain why he changed his mind.

Chester Whiting, another board member who found himself voting to rescind a measure he had once approved, said he did not realize the "ramifications" of the measure until recently.

"There were no objections to it until recently," explained Whiting. "I guess we oftentimes do things like that and find out later what the problems are. I decided that the new policy just created too much frustration and confusion."

The policy was rescinded by a 5-to-1 vote, with Bonnie Johns opposing the move. Two members who may have joined Johns in opposition were not at the meeting, which was a budget workshop session rather than a regular school board meeting.

Vice chairman Susan Bieniasz, who along with Sue V. Mills missed the vote, said she was "upset" that a policy decision was made at a workshop session. "I was really very surprised and unhappy about it," said Bieniasz, who supported the new grading policy. "I had feelings to add to the discussion that might have been pertinent to the vote."

Saunders responded that it was legal and common practice for the board to move into regular session when a timely issue comes up at a special meeting.

Johns said she had philosophical problems with the "weighted" grade system. "It is variable, capricious and contaminated," she said.

"Our system should be geared to try to pose to strengthening the ability to failstudents. Sure, there may be students who slip through, but I'd rather subjected to these negative kinds of forces. I'd rather bend over backwards trying to institute success in students."

Although the school administration, led by Superintendent Edward J. Feeney, claimed that it was merely following the dictates of the school board when it tried to implement the new policy, it was clear from the beginning of the controversy that the adminstration did not like it. Feeney's deputy, Dr. Alan Chotiner, developed the attendance factor in grading several years ago.

The rescinded policy was intended as an interim measure for this year only. A task force of administrators, teachers and parents is in the process of developing a permanent grading policy for the school system and is expected to issue a report this spring.

"Whether accurate or not, the public and the teachers interpreted the interim policy as a lowering of standards," said board member Maureen Steinecke, who voted to rescind. "The task force will have to keep that in mind."