State policymakers recently dipped their toes into one of New York’s most politically charged education issues: teacher evaluations.

At a meeting this month, state education department officials outlined plans to revamp the unpopular teacher-rating system, which was essentially put on hold more than two years ago. Shortly after, the state teachers union called for faster action setting the stage for a new round of evaluation debates.

To help explain the brewing debate, Chalkbeat has created a guide to the current evaluations, how they came to be, and what might be in store for them.

Here’s what you need to know:

How do New York’s teacher evaluations work now?

Teachers are evaluated based on two components: students’ academic improvement and principals’ observation of their teaching.

Every district creates its own state-approved evaluation plan that spells out how they will measure student learning. In 2015, state policymakers temporarily banned the use of grades 3-8 math and English state tests in evaluations.

In New York City, teams of educators at each school pick from a menu of assessments called “Measures of Student Learning.” Among the options are developed essay-based tasks and “running records,” where students are assessed as they read increasingly difficult texts. They can also choose to include the results of science tests or high-school graduation exams. (Certain teachers — such as those who teach physical education — are evaluated based partly on their students’ scores in other subjects.)

Teachers receive one score based on how much students improved academically, and another based on principals’ ratings. The combined scores are translated into one of four ratings, ranging from “highly effective” to “ineffective.”

Teacher evaluations must still be a factor in tenure decisions and three “ineffective” ratings can trigger a teacher’s firing.

What are the outcomes of the current system?

Nearly 97 percent of New York City teachers earned the top two ratings of either “effective” or “highly effective” in the 2016-17 school year, according to preliminary numbers presented by the city teachers union president at a meeting in October. That is an increase from the previous year when 93 percent of teachers earned one of those ratings.

How did we get here?

Until 2010, teachers were rated either “satisfactory” and “unsatisfactory,” and individual districts and principals were given latitude to determine how those ratings were assigned.

But in order to win a federal “Race to the Top” grant that year, New York adopted a new evaluation system that factored in students’ standardized test scores — a move strongly opposed by many teachers, who consider the tests an unreliable measure of their performance. The new system was based on a 100-point scale that allotted 20 points to state tests, 20 points to local tests, and 60 points to principal observations.

The battle lines were redrawn again in 2015, when state lawmakers led by Gov. Andrew Cuomo sought to make it tougher for teachers to earn high ratings. The new system allowed for as much as half of a teacher’s rating to be based on test scores.

But that plan was never fully implemented. Following a wave of protests in which one in five New York families boycotted the state tests, officials backed away from several controversial education policies.

In late 2015, the state’s Board of Regents approved a four-year freeze on the most contentious aspect of the teacher evaluation law: the use of students’ scores on the grades 3-8 math and English tests. They later allowed districts to avoid having independent observers rate teachers — another unpopular provision in the original law.

Why is the state looking to overhaul the system now?

Over the past few years, state policymakers have revised New York’s learning standards and the annual exams that students take. Now, they are turning to the evaluation system.

The moratorium on the use of certain test scores in teacher evaluations expires after next school year, so the clock is ticking for state education officials to come up with a new system. They have said they hope to have a new system ready for the 2019-2020 school year — but they also floated the idea of extending the moratorium in order to give themselves more time.

What could change?

Everything is up for debate.

First, state policymakers must decide whether to create a single statewide evaluation system or let local school districts craft their own, as the state teachers union is urging.

Second, they must decide what to put in the evaluations. Should they include test scores, principal observations, or other measures? If they allow tests, they must determine which kinds to use and how much to weigh student scores.

However, they may run up against some obstacles. Besides the relatively short timeline, major changes to the evaluation system could require state lawmakers to revise the underlying legislation. And any new student-learning measures they hope to use could prove costly to develop.

Who are the key players and what do they want?

State Education Commissioner MaryEllen Elia has made it clear she wants to oversee a careful redesign process that will involve teachers and could lead to a revamped, statewide evaluation system. “This isn’t going to be a fast process,” Elia said during a legislative hearing at the end of January.

State teachers union officials have called for a much quicker process that results in local school districts crafting their own evaluations — a move that could eliminate the use of test scores. “First and foremost, the teachers that we represent believe that the time to fix [teacher evaluation] is this year,” said Jolene DiBrango, executive vice president of the New York State United Teachers, after the state outlined its plan earlier this month. Since then, union officials have said they want to work collaboratively with the education department.

Gov. Cuomo has shied away from this issue after pushing for the deeply unpopular 2015 law that tried to toughen evaluations and inflamed the teachers unions. And he does not appear eager to revisit the issue this year as he seeks reelection. His spokeswoman, Abbey Fashouer, told Chalkbeat: “We will revisit the issue at the appropriate time,” and noted that the moratorium will remain in effect until the 2019-20 school year.

State lawmakers have not indicated that overhauling the teacher-evaluation law this year is a top priority.

During a city teachers union event in December, Assembly Speaker Carl Heastie said he was not sure the state could get to a “final idea” by the end of this year — but that he wanted to “start the dialogue.” The senate majority leader, John Flanagan, did not respond to a request for comment.

“I have not heard any movement on teacher evaluations this year,” said Patricia Fahy, a Democratic assemblymember who represents Albany, in an interview this week. “Normally something about that would be bubbling up already.”