In a move that would place Cambridge on the vanguard of educational reform, School Superintendent Bobbie J. D’Alessandro wants to redistribute city public school students on socio-economic, rather than simply racial, lines.

D’Alessandro has proposed a plan to consider whether students qualify for a free lunch—an indicator of socio-economic status—when assigning them to elementary schools.

At a public hearing last night, she heard for the first time how city residents feel about the new plan, which would be the first change to the system of “controlled choice” since 1989.

The Cambridge Public School System was among the first in the nation to voluntarily desegregate when its controlled choice system, concentrating on racial balance but incorporating other factors, was implemented in 1980.

Now the district is poised to be one of the first to attempt to balance along class lines.

“It’s cutting edge,” D’Alessandro said. “We’re one of four school systems in the country that’s considering it.”

D’Alessandro points to current discrepancies between schools—and evidence that when poor students are grouped together they suffer from dimished performance—as a defense of the changes she proposes.

At the Harrington School in East Cambridge, 80 percent of students qualify for a free and reduced lunch, while at the Cambridgeport School, only 20 percent do. The city average is 47 percent.

After more than a year of research and planning, D’Alessandro wants to pass the new plan and put it in place for the 2002-2003 school year, requiring a school board vote before the end of the year. Both incoming kindergartners and transfer students would be affected.

Last night’s hearing had been rescheduled from last Tuesday, an indication that behind the scenes D’Alessandro has been working to gain more support from School Committee members. At the hearing, Mayor Anthony D. Galluccio, the School Committee chair, suggested a unanimous vote was possible if the plan was further refined.

Indeed, the most recent draft—and the presentation last night—focused heavily on improving schools that have traditionally been underselected by parents. Audience members were supportive of the plan on the whole, but questioned whether it was possible without making the less popular schools more desirable.

One of the main concerns with the new plan is that number of mandatory assignments to elementary schools may increase.

“If this really increases the number of mandatory assignments, then [School Committee members] have something to worry about,” said Lenore A. Prueser, director of the system’s Family Resource Center, which is responsible for administering the school assignments.

Edward B. Fiske, a former education editor for The New York Times and author of the popular Fiske Guide to Colleges, said it was important to make all school options attractive.

“You can’t have choice if you don’t have choices,” said Fiske, who is researching school diversity in Cambridge for the Century Foundation.