Last week, Chicago Public Schools officials proposed using socio-economic demographics instead of racial criteria to fill seats in the district’s magnet schools and selective enrollment programs. Parents, teachers and principals are scrambling to understand what the new admission system will mean for them and their schools.

Since 1980, a federal court has capped white non-Hispanic enrollment at CPS magnet and test-in schools at 35 percent of the student body. In 2007, the Supreme Court forbade school districts from assigning students by race, and the federal court decree was vacated this September.

Under the new proposal, the first 50 percent of seats at test-in institutions like Young and Jones, and at competitive elementary programs like Skinner classical and South Loop’s gifted center, would be filled by students with the highest test scores.

The other 50 percent of seats would be filled using test scores and socio-economic criteria.

CPS will calculate the latter for each of the city’s 874 census tracts using median family income in each tract; parental education; the percentage of owner-occupied homes; single-parent homes; and homes where a language beside English is spoken.

Students would then be assigned to one of four groups corresponding to their socio-economic score. Students with the best scores from this pool would then fill the remaining 50 percent of seats at test-in programs. Enrollees won’t come equally from each of the four lowest-to-highest socio-economic groups; only students with the best results would be offered a seat.

Also new is how offers to the test-in high schools are made. Students can expect to receive one offer based on a computer algorithm rather than how they ranked their preferences on their application. Principal discretion, the policy allowing principals to choose 5 percent of incoming freshmen classes, will be centralized and subject to audits and review.

At the magnet schools, siblings of existing students would be enrolled first. Fifty percent of the remaining seats will be filled by neighborhood students via a new “proximity lottery” — 1.5 miles for elementary schools, 2.5 for high schools. The remaining seats will be filled through a lottery using students from the four socio-economic groups. Principal discretion at magnet schools will cease for one year.

The proposal is both drawing praise and provoking questions, many of the latter about how the new system will affect the diversity of student bodies in the best public schools in the city.

The new rules for the magnet schools appealed to Dona Nishi, a South Loop resident whose eldest child is applying for admission into kindergarten programs at LaSalle Language Academy, Andrew Jackson Elementary and the regional gifted program at South Loop Elementary.

Under the CPS proposal, if the child makes it into either LaSalle or Jackson and enrolls there, Nishi will know the family’s younger child, a 2-year-old, will gain automatic entry to same institution when she comes of age.

Keeping families in the same schools creates cohesion, said Nishi, who sits on the South Loop Elementary’s local school council as a community representative. And worries about cross-city pick-ups and drop-offs are gone. “If you have three or four kids, and have to send them to three or four schools, carpooling is a nightmare,” she said.

Dr. Joseph Powers, principal at Jones College Prep, one of the nine highly competitive test-in high schools, worries his school could lose the diverse student body it has cultivated over the years.

Jones has made racial diversity a core value, actively seeking students from neighborhoods underrepresented at the school.

Powers said Jones enrolled 829 students for the 2009-2010 school year. Latino students comprise 31.9 percent of those students. White students represent 28.1 percent, while black students make up 25.5 percent of Jones. Asian students and Native Americans comprise 13.8 and 1 percent, respectively.

“The people who worked on this say, based on data, other school districts and other cities were able to determine there is enough correspondence [with race] in these socio-economic factors that you will have the more integrated environments,” he said. “But I just truly do not know if that will be the case or not.”

The education magazine Catalyst recently noted that 10 out of the 15 top elementary magnets — including Near West Side schools Jackson and Galileo — are in Chicago neighborhoods that are whiter than the average Chicago neighborhood.

“The way that we did this plan was to try to mirror the socio-economic mix of the schools as they exist today, knowing that they are working very well,” said Katie Ellis, a project manager in CPS CEO Ron Huberman’s office at a hearing Saturday about the changes.

During the hearing, held at Andrew Jackson Elementary, a popular magnet school, parents and teachers raised concerns about diversity.

“My favorite thing has always been seeing kids from difference races, background and economic statuses … being kids, being friends, being together,” said Jackson teacher Edna Otero. “Anything that puts that in jeopardy would worry me.”

Other parents asked more tactical questions, such as a man who wondered whether it would be better to enter his child in the proximity lottery for a magnet school, or seek entry through the city-wide socio-economic lottery. Parents can choose to enter one or the other.

Another line of questions had to do with whether CPS should cap the number of students who attended private elementary schools in the best public high schools.

Across all nine test-in high schools, 85 percent of students came through the CPS system; the rest were private, said Abigayil Joseph, from CPS’s Office of Academic Enhancement.

Jackson parent Sharon Shelton told the CPS hearing officers Saturday that neighborhood high schools needed to be improved, especially given the limited space in the selective enrollment institutions.

“Where is the information saying you are going to bring these schools up?” she said. “A lot of kids are going to be thrown in the pot where they’ll have to go to their neighborhood school.”