Don Feliciana can't quite remember how he landed in Minnie Reid's sixth grade class at the Overlook Elementary School in Prince George's County.

"I know [that] I know where I used to live, but I just can't remember," said the 12-year-old, who now lives near the school in Silver Hill, an area of rental apartments just over the line from the Hillcrest section of Southeast Washington.

Don's confusion is understandable. In the last six years he has attended five county schools, including one school twice. As his mother moved from home to home, he has crisscrossed the county on school buses since he was in the first grade. Don's travels are not unlike those of many Prince George's school children.

The turnover rate in Prince George's elementary schools--the percentage of children who enter and leave a school during a year--has averaged 40.5 percent since it was first calculated in 1976, nearly triple the rates in neighboring Fairfax and Montgomery and higher than any jurisdiction in Maryland except Baltimore City. District schools do not maintain records on turnover.

In some Prince George's elementary schools, the turnover rate has averaged well over 60 percent for the last few years. Ten of the 27 children in Minnie Reid's class at Overlook--where the turnover rate was close to 65 percent over the last three years--were not in the school the year before.

School officials say this high level of student mobility is linked to lower performance on standardized tests. In 1981 and again this year, school testing chief Elwood Loh compared the performance of mobile and nonmobile students on the California Achievement Test, an inquiry prompted by school board members after the county's below-average performance on the test in 1980.

"There was an assumption that kids who come in for a few weeks and leave a school probably don't do as well," Loh said. And that is what he found.

Nonmobile eighth graders, for example, were reading at a grade level of 9.6, almost a year and a half above the national average, on the California test given last fall. That compared with the 7.5 level achieved by students who had attended six or more schools by the eighth grade. Loh says mobility does not explain all the difference between the two groups of students and that highly mobile students also are likely to come from lower-income families, students who traditionally score lower on standardized tests.

It's not just moving, but the family circumstances accompanying a move that leads to lower educational performance, said Thomas Cornille, director of Catholic Social Services of Yuma, Ariz., and co-author of a recent study of national programs dealing with pupil turnover.

"They're going through a divorce or emotional problems or they've had conflict with other schools," Cornille said. "The relocation becomes a result of the problem, not the cause of the adjustment problem."

Whatever the reason, test scores at Overlook are consistent with the finding that high turnover and low scores are linked. Only five of the county's 120 elementary schools had lower third grade reading scores this year and 12 schools had lower fifth grade scores.

Overlook students themselves are aware of the impact of moving on their school work. "I think you decrease instead of increase," said Michael Rich, 12, a superior math student who attended two other schools before Overlook.

"Let's say I'm going to Princeton an elementary school near Andrews Air Force Base for three months and we are doing division. Then I go to District Heights and they're doing multiplication. I'm behind. Then you come to Overlook and they're doing something else. At the end of the year I've learned nothing in math."

Prince George's has a large stock of apartments, almost as many as Fairfax and Montgomery counties combined. Parents move in and out of rental units when they divorce, when rents become too high in one area or when the family is on its way to purchasing its first private home, said Overlook principal Robert N. Griffin.

All of these reasons played a part in moving Don Feliciana, an average student, from school to school. His mother, Carolyn Feliciana Conner, a contract specialist with the Coast Guard, said she moved back and forth between the home of a sister in Capitol Heights and an apartment in Forrestville following a marital separation in 1973. During that time, she also was saving for the house she bought near Overlook in 1982, which caused Don's latest--and she says last--move. "Yes, maybe if I could have stayed in one place his reading/math level might be a little higher than what it is," Conner said.

"For a single parent raising a kid and forced by circumstance to move from place to place, it's hard," she said.

Prince George's, recognizing the problems such students have, has taken steps to help them.

"The new kid on the block may test the protocol in the school," said Ginny Beauchamp, who is part of Prince George's two-member Student Mobility Project, a federally funded program to develop strategies for easing problems in schools with high turnover. "That can be disruptive."

Under the Mobility Project, each of the county's 44 participating schools develops plans and materials designed to make new students feel at home.

There are printed welcome packages with maps and information on the area. The package used at Chillum Elementary, for example, features a 'no homework coupon' good for one incomplete assignment without penalties, and one free pass to the water fountain.

There also is the buddy system, the most common strategy used in coping with high turnover, according to the Cornille study.

At Overlook each new student is assigned a classroom buddy, a bus buddy and sometimes a neighborhood buddy.

New students at Overlook also are encouraged to take advantage of a standing invitation to lunch with guidance counselor Oretha Bridgewater.

"I have an overload at lunch time," said Bridgewater, who splits her time between Overlook and John Bayne Elementary. "Anyone who knows of a new child will come to me and say, 'I know a new child.' So that will give that child and a new person a chance to have lunch with me," Bridgewater said. "I don't even have to wait for the teachers to give me names."

Teachers also must make adjustments for their highly mobile students.

Reid leaves a permanent welcome bulletin board at her classroom door and enforces strict discipline once the students cross the threshold.

Where county rules require work to be graded at least once a week, students in her class get a grade in every subject taught every day. Behavior is charted daily on a separate bulletin board.

Reid says her students, especially the high proportion from single-parent homes, demand a lot from their teachers.

"They will slip up and call me mama sometimes," she said. "They will get as close as I let them get. I see myself as an authority figure. I can't get close enough to be a pal." But she does get close enough to feel loss when her students leave.

"You do feel sad if a student was not having success, then they become successful and then they leave," she said. "But then again you never see the end result in teaching."

"They just have to work a little harder," said Bridgewater of children who move frequently. "Their parents have to work with them and encourage them. Most likely they will keep moving."