MONTGOMERY COUNTY'S school board has accurately reflected the broad swings in the politics of American education over the past decade. In the early 1970s, a great many loose and silly practices crept into the school system, and academic standards declined visibly. The counterrevolution, beginning later in the decade, brought to the board a majority of aggressive and increasingly strident educational conservatives of the back-to-basics denomination. Over the past year in particular, this board has made a series of decisions harshly unfair and insensitive to children who are black, or belong to other minorities.

But along with too many damaging mistakes, the present board has made changes that most Montgomery County parents will want to preserve. Nobody wants to ride the pendulum back to the early 1970s again. There are four seats to be filled on the board, and fortunately the list of candidates offers a way to repudiate the errors of the present board while upholding a firm emphasis on higher standards of academic achievement and behavior in the schools.

Three candidates -- Barry M. Klein, Timothy J. O'Shea and Marilyn J. Praisner -- are unusually well qualified and deserve election on many grounds. All have long records of interest in the schools, and have demonstrated consistently clear judgment. We believe that they will keep the school system moving steadily toward a sober and rigorous definition of education.

The fourth seat is a harder choice. Odessa M. Shannon and Robert E. Shoenberg are both able people, offering different kinds of experience. Mrs. Shannon, an official of the federal Equal Employment Opportunity Commission, has worked for years with the county's racial and ethnic minorities. Mr. Shoenberg, dean for undergraduate studies of the University of Maryland, would provide a direct link to the academic world. In our view, because of the divisive record of the present board and the deep suspicions that it has generated, Mrs. Shannon's contributions would be more valuable in the present circumstances.

Montgomery voters might keep it in mind that they will be setting directions for more than their own schools. Just as Montgomery's school system has been affected by national trends over the years, the reverse is also true. No school system in the country is better equipped to lead the way in developing the full range of the abilities of the children entrusted to it. Wise choices in this election will give new momentum to more demanding and more rewarding public education -- and not only in Montgomery.