You've just spent weeks finding a new aide for your classroom. She's enthusiastic. You're excited. You train her and relax knowing you've put together another winning team. Then you find her taking longer breaks than she should, or talking on the phone too much, or calling in sick or arriving late. Another wonderful possibility is on the skids . . .

If only you could find an employee who would arrive on time every day, who would rarely get sick, who would work hard the entire time she's on your clock.

I'm lucky: I found three such workers. Two are full-time classroom aides, and the third works in the kitchen. All are valuable members of our staff at the Willow Tree Day Care Center in Lanham -- both for the work they do and the joy they bring to their jobs. And all three have mental retardation.

These aides assist teachers in all aspects of child care, from changing diapers to serving lunch to reading a story. Our aide in the kitchen is responsible for washing dishes, counting out plates, napkins, cups and utensils for lunch and helping the cook with simple food preparation.

Before you say, "Oh, no. Not at my center you don't!" let me give you a brief description of one. She has a work ethic that would put most of us to shame. She arrives on time every day, ready not to talk on the phone or take coffee breaks or visit with the other staff members but to work. She takes apparent joy in the repetitive tasks others might find tedious. She is even-tempered and cheerful, and I've never known her to be sick. All she asks is that she be told she is doing a good job, for she wants to please. That means more to her than the money we pay her or any title we could bestow on her.

The parents of children at our center in Prince George's County have accepted these developmentally disabled workers with a graciousness we didn't expect. But we have also been very careful in selecting the right kind of worker.

The two organizations we work with, the Association for Retarded Citizens of Prince George's County and the Special Education Department of the Prince George's County Public School System, understand our needs and put forth a great deal of effort in the screening process. Once they have found someone they think might be a suitable candidate, they bring him in for an interview.

If we do accept an applicant, a trainer from one of the sponsoring organizations comes along to teach the skills needed to become an aide. Once the applicant has mastered the job, the trainer gradually ceases daily supervision, but continues to drop by from time to time to monitor progress and address any problems that might arise. The sponsors remain active partners in the venture. Without their support and wise counsel, we would flounder.

I know this must sound very rosy, the answer to every day-care director's employment problems, right? Wrong. There are limitations to such a program, and to enter into it without recognizing and accepting some of the constraints is foolhardy. For instance, some of the handicapped aides cannot be left alone for long periods of time. Initiative may be lacking. A break from the ordinary routine may be as disconcerting to a handicapped aide as it is to the young children in the room.

And you may have people on your staff who balk at the idea of working with "those people." It takes an extraordinary teacher to meet this kind of challenge. It is not easy to be patient with a person who, though an adult, may have the emotions of a child, whose feelings are easily hurt, who will cry and pout and perhaps become sullen and uncommunicative, who will find ingenious ways to avoid unwanted tasks. It is frustrating and time-consuming and takes more patience than a lot of people have.

But if the problems exist, so do the rewards. And I believe the children are the biggest winners, for they are the ones who benefit from the unconditional love and joy these people bring with them. This program also exposes the children to a different kind of person, a person they can come to know and appreciate as an individual, yet no less a person than anyone else.

To the disabled person it means a chance at self-respect and some degree of autonomy. A day-care center is a very nurturing place, not only for the children but for the people who work there. Individuals with mental retardation feel safe and protected; it gives them a place to belong, a place where they feel needed and wanted and appreciated -- and rightly so, because they are.

-- Judith Vaughan is co-owner and director of the Willow Tree Day Care Center in Lanham.