Legislative leaders are expected to sign off on an ambitious set of education policy changes Tuesday night that will lengthen the probationary period for new teachers, award merit pay, and make it easier to fire a school system’s lowest performers.

Underpinning the changes is a new evaluation system that will be used in a number of high-stakes compensation and employment decisions. Though a number of Gov. Andrew Cuomo’s equally ambitious plans were foiled, the changes coming to teacher tenure and dismissal rules are significant, and a school-takeover provision will limit the city’s influence over its most struggling schools in future years.

Emerging after months of intense lobbying, the bill had few fans outside of the Cuomo administration on Tuesday. Charter school advocates said they had been left out; Assembly Democrats said their leadership had agreed to too many of Cuomo’s ideas; and Republicans complained that state government was reaching too far into public education.

“We’re not going to negotiate very bad to bad and say we’re happy with it,” city teachers union President Michael Mulgrew said.

Here’s a rundown of the changes included in the bill.

Teacher evaluations: Teachers will face another new evaluation system next year, and it will include outside evaluators and a heavy emphasis on state tests.

The state education department and the Board of Regents have been tasked with working out many of the details, and other aspects will need to be decided by Chancellor Carmen Fariña and the city teachers union.

The evaluation system still come from combining state test scores and evaluations, but will no longer rely on percentages — as in the current system, with state test scores accounting for 40 percent of an evaluation, while observations count for 60 percent. The scoring rules that determine how those become final ratings will be decided centrally, shifting control away from districts. (To be fair, the state did decide the city’s current system, too, after former Mayor Michael Bloomberg and the union could not agree.)

State test scores will make up up to half of the evaluation for city teachers unless the city and Mulgrew agree to add an additional assessment. For teachers of students or subjects not covered by state tests, the state will be determining what assessments are used to calculate evaluations, according to Cuomo administration officials, and it’s unclear what the timeline is for doing so.

School takeovers: The bill separates low-performing schools into “failing schools” that have been bottom-ranked for three years, and “persistently failing” schools that have floundered for a decade. The city has two years to turn around the first camp and just one year to revamp the second, during which time the chancellor gets extra authority to make changes.

If the schools don’t make enough progress, then the city must appoint a receiver, which can be a nonprofit, another district, or an individual. The receivers have broad authority: they can modify a school’s budget or curriculum, increase salaries, or turn district schools into charters, and they must bring in more social and health services.

The receivers can also fire principals and force teachers to reapply for their jobs before a hiring committee. If they want to change parts of the school covered by the teachers contract — such as the length of the day or year, or class size — they must negotiate with the union. The plan will come with $75 million to help the state’s 27 “persistently failing” schools next school year, a larger amount of aid than Cuomo originally proposed.

Teacher tenure: Next year’s new teachers will have to wait four years before becoming eligible for tenure protections, and newly appointed administrators will also have to wait four years. Teachers and administrators already in their positions will still be eligible after three years.

One major objective Gov. Cuomo did achieve: tying tenure to evaluations. Teachers will only be eligible for tenure if they earned an effective or highly effective rating in three of their previous four years in the classroom. If a teacher earns a high rating for three years and then earns an ineffective rating in year four, he or she wouldn’t be eligible for tenure that year. (The city could give the teacher an additional year, but wouldn’t be required to do so.)

Union officials noted that principals have already been looking at evaluations when making tenure recommendations. But the plan puts significant new, formal pressure on rookie teachers to avoid low evaluation ratings.

Teacher dismissal: 3020-a, meet 3020-b, the new teacher-termination provision for teachers who repeatedly earn ineffective ratings.

Districts will be allowed to charge a teacher with incompetence after he or she earns two ineffective ratings in a row, and the proceedings would have an expedited 90-day timeline. A teacher will have to provide evidence that they are effective to win an appeal hearing.

Districts will be required to bring charges against teachers who earn three ineffective ratings in a row, with a 30-day timeline for the proceedings. A teacher will have to prove fraud to win an appeal.

Merit pay: Teachers who receive a highly effective rating next year will be eligible for $20,000 bonuses, administration officials said. The state is setting aside $20 million, which would cover 1,000 teachers — significantly fewer than the more than 5,700 teachers who earned a highly effective rating in New York City alone last year.

Cuomo administration officials said they expected the new evaluation system to result in fewer top ratings in the future.

Loan repayment for top graduates: Up to 500 students each year who agree to teach in New York public schools for at least five years after graduating with a master’s degree in education from SUNY or CUNY will be eligible for loan repayment help from the state. They will have had to achieve “academic excellence” while earning their bachelor’s degree somewhere in New York state.

Teacher education: The state’s graduate-level education schools must establish admissions standards that include a minimum score on the GRE or another admissions test and a 3.0 undergraduate grade point average. Schools wouldn’t be able to exempt more than 15 percent of accepted students from those standards.

The state education department will stop graduate programs from admitting new students if fewer than half of their students pass each test needed for certification for three consecutive years. If those programs don’t quickly improve, they would be shut down when already-admitted students finish their courses.

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