Mayor Bill de Blasio on Saturday called for an end to the test required for students to get into the city's eight specialized high schools, arguing it is an impediment to racial diversity at the schools. He also announced that the city will reserve a fifth of the seats at the schools to students who are from lower-income families and just missed the cut on the exam.

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 five thousand seats.

What is the city going to change?

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 de Blasio has presented an actual plan to scrap the test, the Specialized High School Admissions Test (SHSAT).

Writing an op-ed that was published Saturday in the education website Chalkbeat, de Blasio said that starting in September of 2019, the city will offer 20 percent of seats at the schools to students from low-income families and just missed the cut on the exam.

"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 the op-ed.

The specialized high schools rely solely on SHSAT to admit students every year.

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.

What long-term changes is de Blasio proposing?

He wrote that he wants the New York state legislature to replace SHSAT with a new test admissions process so the specialized high schools select students based on a combination of the student's rank in his or her middle school, as well as the student's scores in statewide exams.

Using students' middle school rankings 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.

To scrap SHAT at the Bronx High School of Science, Brooklyn Technical High School, and Stuyvesant High School, the mayor will need the state legislature's approval, as those three schools are required by law to admit students based only on the exam.

The mayor's proposal to scrap the exam faces an uphill battle in the state legislature, however, because 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.

It is unclear why the mayor is pushing for these changes now, but his new schools chancellor, Richard Carranza, has been speaking out extensively about segregation in the city's school system.

While de Blasio did not mention the segregation explicitly in the op-ed, he did point to the racial disparities in acceptance rates at the specialized high schools, which overwhelmingly accept more white students than black and Latinos every year. Many advocates have pressured the mayor to address the segregated school system.

The powerful alumni groups from the specialized high schools have successfully lobbied for decades to keep SHSAT, and are likely to argue that the mayor's changes would lower the standards for entry.

"Anyone who tells you this is somehow going to lower the standard at these schools is buying into a false and damaging narrative. It's a narrative that traps students in a grossly unfair environment, asks them to live with the consequences, and actually blames them for it," the mayor wrote in his op-ed. "The new system we're fighting for will raise the bar at the specialized high schools in every way. The pool of talent is going to expand widely and rapidly."