NURSERY SCHOOLS appear to be a growth industry these days. Despite the fact that this country's population of 3-and 4-year-olds has declined over the past 15 years, more and more children in this age group are attending organized pre-kindergarten schools. The Census Bureau reports that nearly 2 million 3-and 4-year-olds were enrolled in educational programs in 1980, while only 520,000 were enrolled in 1965. A hefty 36.7 percent of our very young children are going to school now, compared to a modest 10.6 percent in 1965. Changes in families and neighborhoods, combined with growing scientific evidence that children learn a great deal before the age of 5, contribute to the increasing demand for programs to enhance the academic and social skills of our children.

As the mother of a 2-year-old, I've been looking into pre-school programs for next fall, a process that can be as intricate as applying to college. There is competition for places, admissions requirements, social and sometimes cognitive testing, and distinct educational philosophies, different curriculums, and special equipment to choose from. Tuition, usually ranging between $1050 and $3,350, can cost more than my generation, the parents of these kids, paid for tuition at Harvard.

It's easy to feel pressured as we hurry to apply early, since most pre-school programs have more applicants than places. There are other pressures on those who want not only the best experiences for their kids right now, but believe a nursery school's reputation will somehow give them an entree to the "right" primary or secondary school, even to college. Parents can wait as anxiously for pre-school admissions decisions as they did for their own college acceptances.

"You get into this Washington madness of getting into the 'right school,'" says Jeni Vitarello, mother of two young children. "When our daughter was about 2, I went to look at a school. All the mothers and kids there were nervous. I was nervous. I decided then it wasn't worth it." Her daughter spent a happy two years at a neighborhood school and now attends a prestigious nursery the Vitarellos chose "because we like the program, the people." They haven't decided yet where they'd like her to go from there.

Is there a "right" nursery school that will guarantee a place in the Ivy League for your child? At schools like Sidwell Friends in Bethesda and Northwest D.C., and the Potomac School in McLean, children accepted into the 4-year-old programs can continue through the entire school without re-applying. But many schools offer programs only through first or third grade, and children applying from there stand on their merits. Not every Beauvoir student goes on to St. Alban's or National Cathedral, just as not every student from St. Alban's gets into Harvard. "Good" schools usually get their reputations because they offer good programs, but relying on prestige alone can cause bitterness and disappointment if children are unable to take the next "right" step.

Most nursery school directors urge parents to visit several schools and observe classes. "The most important thing to look for is that the teachers and directors have the attitudes you want to see developed in your child," advises educational consultant Sherry Migdail, currently with the Montgomery County school system. Attitudes toward other children, adults, learning and discipline will affect children far beyond the pre-school years. Partly as an outgrowth of child development research, pre- school programs have different approaches to teaching, and parents should decide which approach best suits their child.

Nursery schools like Beauvoir, National Presbyterian in Northwest Washington, Sidwell and Potomac take a "whole child" approach to teaching and learning. They have strong academic components, but they are concerned with a child's esthetic, physical, social and emotional growth as well. Play, informal and unplanned experiences are all part of learning. One morning recently at the National Child Research Center, a nursery school in northwest D.C., I watched as a child discovered a grasshopper on some playground equipment. Teachers and other children immediately gathered for a spontaneous nature lesson, observing the insect's color and size, as the teacher gave the Cued Speech "handshape" for the deaf. NCRC mainstreams deaf children into its program, which takes children from age 21/2.

These "whole-child" oriented schools encourage creativity, imagination, and powers of expression and aim to stimulate a child's natural curiosity in the classroom. "There's so much social and emotional learning going on at this age," says Jane B. Harter, Director of National Presbyterian. "We provide children with the experiences for thinking, enjoying themselves, learning to be with other children."

The Montessori method is another approach parents can consider. Montessori schools share similar goals for a child's well-being, curiosity, and enjoyment of learning, but their program differs from the "whole-child" programs. Children work in what is called a "prepared environment" with special materials designed to develop muscular coordination, abstract reasoning, and knowledge of numbers, writing, and reading. Many of the materials are built to control error so children can check themselves as they work. At Mater Amoris School in Northwest Washington, classrooms are bright, orderly, feature flowers on the tables, shelves with button boards, map puzzles, and baskets filled with cloths and equipment for doing some of the "practical life skills." As I watched, an older child taught a younger one to polish brass; the teacher worked with another child on phonics. At New City Montessori in Northeast Washington, children spread out on rugs. One worked letters of the "movable alphabet," another washed a kid- sized table with a small pail and sponge.

Montessori programs are known for these tasks and for work with reading, but Deborah Bricker, a teacher at Mater Amoris, says the program also "encourages independent work and logical thought processes." New City has the philosophy that a child's experiences will be enriched by "a student population which reflects the urban mix," and like many pre-school programs, including Sidwell, Beauvoir, and Potomac, seeks children from diverse economic and racial backgrounds.

Still other pre-school programs reflect religious beliefs or specific philosophies and approaches to life. Fairfax Christian School was the first of several private Christian schools in the D.C. area which actively incorporate religious values into their educational programs. Director Robert Thoburn feels that parents "still have an interest in academics, but are also concerned now with moral values and discipline." One hundred children attend Fairfax Christian's 4- and 5-year-old program, and the Thoburns and staff have helped to start 12 other Christian schools in the D.C. area. Children hear the Bible every day, and texts and lessons have a Christian perspective.

The Washington Waldorf School in Northwest D.C., one of 20 Waldorf schools across the country, also bases its program on a specific philosophy, the work of Dr. Rudolf Steiner. An Austrian philosopher, Steiner believed young children learn best through imitation and willingly joining in activities with others, rather than through reason or explanation. About 30 students in the 2-year-old program concentrate on artwork, storytelling, and work with natural materials. "We want to surround a child with the loving care of adults and strengthen him for going on into his learning years," says teacher Carolyn Robinson.

Once parents choose an approach for their child, they should consider how involved they want to be in the program. Most schools inclu Theyde parents as classroom volunteers, fund raisers, and in policy- making positions, but cooperative schools require more. At Tauxemont in Alexandria, parents serve in the classroom on a rotating basis, manage the school, help hire teachers, build playground equipment, and, when necessary, paint furniture or repair the roof. Although some area pre- schools are no longer cooperative, because of changing parent needs and desires, Tauxemont maintains this approach as an important element in the school.

Parents in the District of Columbia can choose a private nursery program or can opt to send their children to one of 122 pre-kindergarten classes operated by the D.C. Public Schools. These classes, started in 1967 with federal funds, were so popular the District has continued them.

In addition, there is the federally-funded Headstart program, run independently, but cooperating with D.C. and surrounding county schools. Headstart serves children from low-income families, but accepts 10 percent of its students, tuition free as well, from families with income above the guideline.

Headstart is the kind of program which studies show makes a tangible difference academically to disadvantaged kids, more than to middle-class children, as they move on through school. "We have classroom goals, family goals, and community goals," said Beverly Langford-Thomas, Director of Headstart in Anacostia, one of several Headstart programs in the area. "We want to build the confidence of the parents as well as the kids." Six of their classes are held in a high-ceilinged, rambling old school building decorated by Howard University students with striking murals. It's a friendly place. One recent day, there was a clothing swap in the basement; kids were busy learning and playing in the classrooms, and a couple of volunteer mothers were painting tiny kitchen furniture in the hall. One mother stopped me and my daughter. "Are you going to enroll her here? You should. This place is great."

The current interest among parents in nursery schools doesn't have only to do with education. It also reflects changes in families and communities, and serves the needs of adults as well as kids. Nursery school, like the day care center, provides "a support system for parents," according to Urie Bronfenbrenner, Professor of Human Development, Family Studies, and Psychology at Cornell. Jay Belsky, professor of Human Development at Pennsylvania State University points out that even where pre-school programs are part-time, they are "one component of a child care package," supplemented by housekeepers, babysitters, and extended day care.

Many of us who don't work outside our homes use pre-school programs to free more time for ourselves, or to spend with younger children alone. There often aren't grandparents and other relatives nearby to call on for advice or instant babysitting, nor other parents at home to provide support. Perhaps because of the loss of this informal network to help with kids, some parents have lost confidence in their childrearing abilities. Dr. Richard Lodish, Sidwell Friends Lower School Principal, sees "more reliance on professionals today to help raise our kids than previously." And mothers turn increasingly to organized groups to find someone for their children to play with. As Lynne Sherald, current president of Tauxemont Cooperative Pre- School puts it, "Nursery school provides experience with other children and equipment I can't offer."