What a contrast with those tumultuous times when chaos reigned at D.C. school board meetings and confidence in public education was slipping at an alarming rate. Today the news from the board and from the classrooms is encouraging. If the caliber of leadership is sustained through 1985, more people may discover that Washington's children get a good education in the public schools. Credit goes to many, starting with the people of the city who vote in school board elections. They have been weeding out the showoffs, small minds and petty politicians who dominated and nearly decimated the school board for so much of the 1970s.

So marked is the change in the school board that last Friday, after three successful years under the presidency of the Rev. David Eaton, members unanimously elected R. David Hall, another hard- working member, as the new president. They also were unanimous in selecting Linda Cropp to serve as vice president, succeeding Nate Bush, whose service won high marks as well. Mr. Bush joined with Barbara Lett Simmons in making the motions to elect Mr. Hall and Mrs. Cropp -- an act of unity unmatched in the lifetime of the elected board.

During Mr. Eaton's term, the board hired Superintendent Floretta McKenzie and, untrue to past board form, actually let a good superintendent do her work. By and large, the members stopped trying to make headlines and started to make educational progress. Instead of seeking to score political points against each other, they sought to help the children score points on national tests.

Parents, teachers, administrators and the students, too, began to notice the difference. This progress brought with it a better relationship with city hall that has meant more equitable budgets, new support and modern equipment from businesses, and an accelerating return to a curriculum focused on basics.

What now? Test scores still could go much higher. Languages, music and sports could stand stronger support as important parts of a balanced and enjoyable school program. As Mr. Hall has emphasized, textbooks and supplies could be delivered more efficiently. And word could be spread still more vigorously among those parents who consider alternatives to public school that good things are happening in the city's classrooms. As for the school board, Mrs. Cropp said it well after her election: "Pettiness and ego gratification fade as we reach for quality education. We must maintain tolerance, objectivity and reason."