As a city that is home to Haitian immigrants, proud Irish Catholics, transient academics and aging Brahmins, Cambridge has long been renowned for both its socioeconomic and racial diversity.

While city policies strive to create public-school classrooms that reflect this diversity, a report submitted to the Cambridge School Committee last week concludes that there are in fact broad socioeconomic imbalances in the city's schools.

"There are two sets of schools in Cambridge--middle-class schools and lower-class schools," says Joseph McKeigue, principal of the Dr. Martin Luther King Jr. School, one of 15 elementary schools in the city.

The report was compiled by a team of consultants led by Harvard Professor of Education and Urban Studies Charles V. Willie.

Although Willie has studied the Cambridge public school system for over 15 years, the report was not an external evaluation but was contracted by the city's School Department.

The consultants were asked to assess the city's 1981 Controlled Choice Student Assignment Plan, an effort designed to promote student school choice, student-body diversity and school improvement at the elementary level.

The controlled choice plan assigns students to a school based on various factors, including the parents' top three school choices, racial balance and the presence of siblings.

The report issued by Willie and his colleagues last week gave the program mixed reviews.

According to Willie, only six of the city's elementary schools are racially balanced, according to the school district's standard, which calls for each school to have a population representative of the diversity in the district as a whole.

Only two of the 15 schools were socioeconomically balanced.

The report also concluded that socioeconomic characteristics of students are associated with academic performance.

And while the report's findings are undisputed, few can agree on how to address the issues it raises.

"The issue of socioeconomic diversity is a major issue... the question is how you do it," said School Superintendent Mary Lou McGrath.

Willie's plan proposes to eliminate the system's widespread imbalances by consolidating many of the city's alternative education programs.

By eliminating the smaller special-needs programs, most agree that elementary school populations would more accurately reflect the city's considerable diversity.