AN IMPORTANT election by a small group of people is about to determine who will fill a top public office in this city: the school board's members will appoint someone to serve as their colleague from Ward One, filling the vacancy left by Frank Smith's election to the D.C. Council. With a serious, low-profile majority now in command and working with a first-rate superintendent, the selection takes on special importance; the last thing this city needs is a return to the bad old days when some board members were more childish than preschoolers.

More than a few people are offering themselves for the job--11 was the count when the deadline passed--and each will be given 10 minutes to address the board on Monday, along with two speeches each by supporters and comments from any other residents who sign up in advance. The choice is scheduled to be made at a board meeting Feb. 16. The challenge, of course, will be to sift through more than the speeches, promises, petitions --and applause--and find the best person to work with the current majority.

No doubt all of the 11 will pledge their dedication to children and the biggest school budgets possible. But more to the point will be their knowledge of what is or isn't in the budget, what kind of curriculum the current board and superintendent are developing and improving and how much experience or expertise they might bring to the board. Above all, the selection should not be hung up in narrow politics, such as who is "Mayor Barry's person" or who vows to battle the mayor for the "independence" of the board from city hall.

The board should begin with a close look at two applicants who have demonstrated keen interest in the board's work, and who sought membership before: Manuel Lopez and Jonas Milton. Each has campaigned impressively before and has shown a steady grasp of the issues.

Though the appointment is only for a short term --it will expire at the end of the year--it could be an advantage if the new "incumbent" chooses to run in the fall. In any event, the representative from Ward One is more than a servant of one neighborhood on this important body; every one of the 11 votes carries equal weight--and now is not the time to shift that weight.