Each summer, Lynn Goldstein does some careful sleuthing among other parents at her son's Fairfax County school and then takes to her computer to write "The Letter."

Addressed to the principal, it is her manifesto for her now-10-year-old son's upcoming academic year. The detailed missives assess her son's strengths and weaknesses, critique the previous year's teacher and describe the instructor she wants for her son in the year to come.

Goldstein started her annual letters after her son had what she describes as a disastrous experience with his first-grade teacher, and she believes they have made a difference. Since then, she's been happy with the teachers he's had.

"We live in an area where there are a lot of pushy parents . . . people who just come right in there and say exactly what they want," she said. "I really hope I'm not one of those parents who does that. I never run in like a banshee. I try to write my letter and hope the [principal] hears it."

The school year may be over, but for an increasing number of baby boomer parents, the hard work has just begun. Their task: landing the perfect teacher for their child in the fall.

Doris Dabney, for example, plans to meet with the principal of her 8-year-old daughter Kai's school, Kettering Elementary in Prince George's County, to ask for a "seasoned teacher" for Kai, who is entering third grade. "Someone," Dabney said, "who would recognize her potential and really work with her--push her hard."

Although school officials say they consider many factors when making up class lists, parents say that lobbying principals is important because, as parents, they know their children best and want the principal to know some things about their child that may not be readily apparent.

What's more, they believe their lobbying works.

For the last three years, Alison McWilliams has asked the principal of her daughter's elementary school in Germantown to place her child in certain teachers' classes. So far, she said, she's 3 for 3, all "excellent teachers."

Across the Washington landscape this summer, parents are listening to the "mom buzz," as it's often called, while at the pool, doing yardwork or buying groceries.

They trade intelligence: which teachers are moving to a different grade level or a different school, which teachers are staying put, who seems burned out, who's enthusiastic, which teachers are strict and which are lenient, who can tolerate frisky children and who wants only quiet ones.

Although teacher-shopping is not uncommon in middle and high schools, the practice is far more prevalent at the elementary level, parents, principals and teachers agree, because children spend far more time with one teacher there.

"You start receiving these letters, and it's pretty amazing," said Linda Goldberg of Hunters Woods Elementary in Reston, who is retiring after 11 years as a principal. "Not only will they ask for a particular teacher for their child, then they name another three or four kids who should be in the room with them."

For many principals, pupil placement is a major source of angst, said Fred Brown, associate executive director of the National Association of Elementary School Principals.

"There are a lot of parents who would like to choose the teacher for their child," said Brown, noting that many parents are suspicious of the pupil-selection process. "In no way do principals just draw names out of a hat," he said, but "that seems to be the perception of most parents."

The association warns principals in its newsletter of the pitfalls that await them each summer, cautioning that pupil placement "is a delicate and time-consuming task that calls for careful planning, kid-glove handling and top-notch PR skills."

At some schools, the process of assigning children to teachers for the fall actually begins the previous spring with preliminary class lists, which are then revised over the summer. Other principals wait and put together the lists in late August when teacher hiring is complete and new students have registered. Often the lists are being rejiggered until the day school starts.

Some principals are wary of any parental input.

Kathleen Holliday, principal of Bells Mill Elementary School in Potomac, discourages parents from making requests. Her teachers draw up the initial class lists, and Holliday adjusts them in the summer as she sees fit.

"I know most of the kids, so I can say who a child would really be good with [and] what teacher would be really good with that particular child," she said.

In a new twist, this year Holliday received two letters from students requesting specific teachers. Impressed by their directness, Holliday plans to honor the students' requests.

Many principals ask parents in the spring to write a short note with information about their child that would be helpful when teachers and principals place pupils. But even though parents are asked not to name certain teachers, many ignore the request or resort to thinly disguised hints.

Rosemary Lynch, now president of the County Council of PTAs in Fairfax County, recalls angling for a teacher who ran a quiet, structured classroom when her daughter was entering third grade. Without using names, Lynch described for the principal the classroom demeanor of the teacher she had in mind as well as the classroom demeanor of the teacher she was trying to avoid.

"It didn't take a rocket scientist to guess which one I wanted for my child," she said. She got her wish.

Some parents are even more inventive.

Goldberg, the Reston principal, recalls the mother who visited the classrooms her child might be assigned to, looking for a way to signal her teacher preference in advance. She found it: The teacher the mother wanted used desks in her room, while the teacher she didn't want had her students sit at tables.

The mother wrote Goldberg that her child needed a teacher who used desks. The tactic worked; Goldberg granted the request.

Fairfax parent Julie Garcia, who has a daughter entering fifth grade and a son who is a rising eighth-grader, draws up one-page "resumes" on both and gives them to her children's principals each summer.

The resumes give a detailed account of the Garcia children's lives, including their schooling history, learning styles and personalities. Garcia even throws in her son's career goal: a helicopter pilot.

Like many military families, the Garcias have moved several times, and Julie Garcia believes the resumes are a quick and effective way of helping principals decide which teachers best suit her children's needs.

Such feverish activity is greeted scornfully by some parents, who say children eventually have to learn to deal with people they don't like or don't get along with, so why shelter them from the experience when they are young?

"Personally, unless a teacher is really off-the-charts awful, my own philosophy is to work with whatever teacher we get, instead of trying to control the issue," said Pete Siler, who has three children, ages 14, 12 and 10, in Fairfax schools. "Our kids have had teachers that other parents and kids absolutely hated, whom our kids--and us--absolutely loved."

Maria Watson, whose son just finished second grade at Poplar Tree Elementary in Fairfax, knows parents who write letters seeking particular teachers but says she wouldn't even know where to begin.

"I feel somewhat at a disadvantage as a working parent," she said. "We only get to know our child's current teacher. I don't know the third-grade teachers. . . . Unfortunately, there is no way in the process for parents who have limited exposure to the school to know the qualities of the next grade's teachers."

Concerned that teacher-shopping excludes parents who aren't as knowledgeable about the school staff, some schools are laying down ground rules.

Peter Branch, head of the private Georgetown Day School in the District, sends a letter in the spring to parents of lower- and middle-school students, explaining the pupil-placement process and asking parents to supply the school with information they feel the school needs in order to make the best decision.

"My feeling is that when you clarify the process to everybody, you provide equity," Branch said. "You are not just having the people who are 'in the know' giving you that kind of information."

As for Lynn Goldstein, a relative asked her recently what she will do when her son reaches middle school.

"Well, he'll be a lot older, and he will only have 55 minutes with somebody at a time," Goldstein said. Until then, she said, letter-lobbying "is critical."

Staff writer Victoria Benning contributed to this report.

CAPTION: In their letters, parents stress children's needs or try to disqualify teachers they don't want.