Amid mounting criticism over deep levels of segregation within the city's public school system, Mayor Bill de Blasio on Sunday announced plans aimed to change the admissions policies at the city's specialized high schools.

What is the Specialized High School Admissions Test?

Students in eighth or ninth grade who want to apply to one of the city's eight specialized high schools — Bronx High School of Science, Brooklyn Latin School, Brooklyn Technical High School, High School for Math, Science and Engineering at City College, High School for American Studies at Lehman College, Queens High School for Sciences at York College, Staten Island Technical High School, and Stuyvesant High School — must take the exam.

The 180-minute test scores potential students based on English Language Arts and math. Test-takers are then ranked based on their scores for the number of questions they answer correctly. If admitted, the student is assigned to a specialized high school based on how he or she ranked the school on the application, the priority the student assigned to the school, and the seats available.

Tens of thousands of students apply to the schools every year for 5,000 seats.

How is the city trying to change admissions policies?

"The single standardized test could never capture all the talent, and the test has to go," the mayor said at a news conference with several elected officials Sunday.

But getting rid of the test requires legislative change in Albany — a challenge. State Assemblyman Charles Barron has introduced a bill to get rid of SHSAT.

Instead of one test, schools would move toward a system that ensures the top seven percent of students from every middle school in the city gets a spot at a specialized high school.

Barron urged the public to pressure their state elected officials to vote for it.

More immediately, the mayor said the city is taking action on its own by expanding a program, the Discovery Program, to help low-income students gain entry to these top high schools. 20 percent of seats at specialized high schools will be set aside for students from high-poverty middle schools who fall slightly short of the admissions test cut-off.

"Now, a disadvantaged student who is just a point or two shy of the cut-off won't be blocked from a great educational opportunity," the mayor wrote in an op-ed that was published Saturday in the education website Chalkbeat.

The specialized high schools rely solely on SHSAT to admit students every year. The cut-off for admissions varies from school to school.

De Blasio has always said that, philosophically, he has been opposed to the way the specialized high schools chose their students, but this the first time the mayor has presented an actual plan to scrap SHSAT.

The mayor called the exam flawed and pointed to socioeconomic barriers — such as families not being able to afford tutors or test preparation courses — putting students from poorer families at a disadvantage in their efforts to be admitted to the specialized schools.

De Blasio said he's pushing the change now, in part, because he is expecting Democrats to win control of the New York state Senate in November.

The mayor said he is not sure if the legislation would pass in the current state legislature session, which ends at the end of the month, but he said he is hoping the next one would take up the issue.

The issue of segregation

Using students' middle school rankings as the basis for admissions would allow more students across the city to be represented — more than half of the students that are admitted to the specialized schools come from just 21 middle schools.

Nearly 70 percent of public school students in the city are black and Latino, but just ten percent gain access to the city's top high schools.

Stuyvesant High School, for example, is welcoming 900 new freshmen in September; just 10 of those students will be black.

But state lawmakers have said in the past that they do not want to change the test. They have listened to alumni interest groups from the schools and have said that the exam is the fairest way to determine who should be admitted.

• New bills aim to boost diversity at city's specialized high schools

The powerful alumni groups from the specialized high schools have successfully lobbied for decades to keep SHSAT. Some have argued that opening up admissions at the specialized schools would weaken them.

De Blasio said that argument is un-American.

Alumni associations from Brooklyn Tech and Stuyvesant High School are denouncing the mayor's move, calling it a complicated and unworkable approach. On Facebook, some called it anti-Asian; Asian students make up the vast majority of students at Stuyvesant and Brooklyn Tech.

De Blasio said his proposal is not anti-anyone, instead calling it pro-opportunity. The city projects that the new admissions policy, if approved by state lawmakers, would add many more black and Latino students to the city's top high schools.