When she first raised the issue publicly, "My fellow school superintendents began calling me up from all over the country and asking, 'Are you crazy, Mary Lou?' "
The crazy idea, explains Mary Lou McGrath, Cambridge's nationally known superintendent of schools, is a hotly controversial proposal to increase social and economic diversity in the district's classrooms. If implemented, the Cambridge proposal would let the city consider not only race but a family's financial and educational profile in determining school assignments.
Expanding the concept to include social and economic diversity alarms those who see it as unwarranted social meddling, perhaps involving intrusion into financial records and family background. Others welcome it as a progressive move toward leveling the playing field.
Either way, Ms. McGrath says, all see it as a step into virtually unknown territory and a turning point in the contentious history of classroom desegregation.
"This would be a very significant step" toward social change in the nation's schools, says Marvin Berlowitz, professor of sociology in the education department at the University of Cincinnati.
One reason for this is that Cambridge's student-assignment plan is already the model for most big school systems throughout the state and in many big-city school systems nationally.
Cambridge currently follows a system known as controlled choice. Parents can apply for any of the district's elementary schools, but racial and ethnic diversity throughout all the schools remains a priority. Some 80 to 90 percent of families get their first or second choice of school.
Despite their racial diversity, however, some of the schools reflect the sharp social and economic differences of the city itself, which includes both faculty families from Harvard and the Massachusetts Institute of Technology as well as the families of blue-collar workers.
"The problem of kids from affluent, well-educated families ending up in one school and those from a lower socioeconomic level being lumped together somewhere else has been around as long as there have been public schools," says Michael Alves, senior education planner at Brown University's New England Desegregation Assistance Center in Providence, R.I., and part of a consulting team studying the proposal. "Finally we have a school district that actually may do something about it."
Mr. Alves adds that Cambridge will be the first major district to attempt such a plan, although a somewhat similar effort has been attempted in La Crosse, Wis.
For Ms. McGrath, the benefits of such mixing seem clear-cut. She has had the idea in mind, she says, since the early 1960s, when she was a second-grade teacher in a Cambridge school that had a rich mix of racial and socioeconomic backgrounds. What struck her then was the mutual learning that went on.
"There were professors' kids," she recalls, "and foreign students ... and then we had kids whose fathers were firemen and milkmen and so forth. The kids learned a lot from each other.... It kept raising the level of learning - the vocabulary."
By 1979, when she was director of Cambridge's elementary education, McGrath raised the issue of socioeconomic mixing. But, she says, "people weren't ready for it. Racial diversity, yes, but not socioeconomic diversity."
It remains unclear whether the city now is any more ready for the plan, which is prompting many observers to charge that the district is moving into territory where it has no business being.
"Sprinkling what we deem smart rich kids around like a pepper shaker is not the solution," says Sandra Perry, a professor of elementary education at Franklin Pierce College in Rindge, N.H. "It may make a pretty picture, but I think it's manipulating children to make a school district look good when it doesn't necessarily accomplish that."
Professor Perry, who worked in Cambridge schools while studying for her doctorate at Boston College, maintains that "We're overlooking the important human element - what is best for the children."
The solution for Cambridge, Perry says, is to examine the success stories in the city schools. "What makes [a school] good are factors like effective teachers. Word is out there. Everyone knows what schools are good," she says. "They have some excellent teachers there. That's where the effort and administrative change should be placed in Cambridge."
The charge of using students as modular pieces in an unproven social plan is at the bottom of much of the resistance by some education experts. "Let us be student-driven and not adult-driven," says Cheryl Evans, professor of education at the University of Evansville in Evansville, Ill. "Cambridge is a tinder box, with old families, lots of complications and potential resistance. Policymakers have to be crystal clear about objectives. It's not just automatically a great idea."
But James Alouf, professor of education at Sweet Briar College in Sweet Briar, Va., calls the Cambridge proposal "a noble experiment."
"With heterogeneous groups, you have the best opportunity for what public education was created for," he says. "That includes introduction to life in a democratic society."
Some question whether such mixing could slow the pace of learning for some students.
Marguerite Penick-Parks, professor of education at Ripon College in Ripon, Wis., says it does not have to be an obstacle.
"If a teacher handles it right, the upper-level students can learn as much as the lower-level students," she says. "We're wrong to have all these talented and gifted classrooms where they get to do projects and have all the fun. Lower students would learn just as much if they also were allowed to learn that way. The only way for kids to understand various lifestyles is for them to be exposed to them."
Alouf concurs: "In the final analysis it hasn't been established as true," he says. "The notion that every kid can succeed to some degree is starting to catch on."
Cheryl Didham, assistant chair of the division of education at Baldwin-Wallace College in Berea, Ohio, has seen the same problem teaching in Cleveland schools and thinks the Cambridge idea is a good answer.
"Teachers tendto stereotype areas of a community, such as the project kids, or 'the other side of the track' kids," she says. "Even in rural areas, if it has a housing project, they classify children from lower socioeconomic levels."
To her, a mixed classroom itself is an education. Summing up the views of many of her colleagues, she says that all kids will benefit "if a teacher touches the higher expectations of the class."