SLOWLY BUT NOTICEABLY, Washington's public school system is shedding the grim reputation it had to bear for so many chaotic years of revolving superintendents and cabin-fevered school board members. Name-calling, door-slamming and racial epithets have given way to low-key efforts to deal with operational challenges, classroom activities and even the progress of the children. The dividends of this atmosphere include a hard look at how the merit of the city's teachers might be assessed more usefully.

Parents, of course, have their own views about who is a "good" teacher. But without some effective, formal evaluation procedure, the views of parents or anybody else may not amount to a hill of memos; without extraordinary measures, the retention of tenured, certifiable mediocrity can become a way of life in too many classrooms.

This week, a city-wide organization of parents has released recommendations for improving teacher evaluation that appear to have critical support not only from parents, but also from school board and union officials. The recommendations are not all that extraordinary, nor are they all that costly. But they could have an impact:

A small group of "teacher-observers" -- specialists in subject matter -- would be formed and make on- the-scene reports on all teachers, tenured or not. Parents, too, would be involved, perhaps through questionnaires on homework, their children's attitudes toward teachers and other aspects on which they have opinions. Classroom instruction would be weighed most heavily; other factors would be collegiality (important in team-teaching), extracurricular activities, grasp of subject matter and communication with parents. Obviously, progress in student learning should -- an would -- count among the criteria. But less obviously, improvements in scores alone are not a fair measurement, because they may not reflect other problems in the classroom.

Principals would continue to have the chief responsibility for evaluating every teacher every year, but regular observation-team visits would provide evidence for more informed judgments and, in many instances, recommendations for additional teacher training. With these clearer and more intensive procedures, the likelihood of grievances and litigation could well diminish, at the same time easing the way and strengthening the cases against those whose performances do not measure up.

The danger is that all proposals like these get talked about but not put on the books. A joint school board/union committee is due to issue its report soon--and public insistence on improvements might well make a difference.