YOU GENERALLY don't hear much about these goings-on until it's too late and already out of immediate control, but Washington's public school teachers and the school board have reached the final stages of negotiations for a new contract. The last time this happened, as many parents remember all too well, the result was a bitter, 23- day strike that accomplished nothing for the school board and even less for the hapless students. These young people cannot afford another experience like that one, nor should they have to. Today--for a significant change--the parents do have a voice, and it happens to be speaking with good sense to both sides in the contract talks.

Parents United for Full Public School Funding, a 600-member citywide coalition formed in the fall of 1980 to lobby for higher school budgets, has completed a thoughtful analysis of the issues currently in dispute between the Washington Teachers Union and the school board. Not surprisingly, its recommendations please neither the union nor the board--but in them there is important room for accommodation.

There is one other key change this time: teachers' salaries are on the table along with working conditions --which means that tradeoffs are possible. Without any ability to talk money last time, the board's insistence on longer school days and work years fell on deaf ears; teachers who had never even been members of the union saw red and walked out rather than retrogress, and they managed to preserve the status quo.

That status should be changed, and can be. Parents United is proposing that teachers' salary increases be more closely tied to their performances in the classroom, and that their workday be lengthened. Along with improved evaluation procedures that would be a factor in pay increases, the parents' group supports other money incentives for additional quality work, including some version of the union's proposal to reward teachers for minimizing the use of sick leave.

Another key recommendation is that the school day be extended to 7 1/2 hours instead of the current 6 1/2 (each includes one-half hour for lunch), bringing it in line with hours in neighboring jurisdictions. Parents United also supports a longer work year for the teachers, relief from nonteaching duties and better record-keeping on student progress that would reduce the "excessive burden" now placed on teachers.

In this middle ground there are proposals that should be attractive to the teachers as well as proposals long sought by the school board and administration. And precisely because there is a third critically important party to all this--the students--what the parents are saying and standing up to has nothing to do with which of the two sides at the bargaining table wins the most "points." They want the points scored in the classroom, with teachers whose competence and hard work are properly evaluated and rewarded. That is a message that neither the union nor the board negotiators--nor, if the contract goes to binding arbitration as expected this month, the arbitration panel--should ignore.