About 200 people attended a forum in Brooklyn Monday night about high-stakes testing.

The architect of many of the metrics the city uses to assess teachers and measure student growth spent Monday evening defending his work against a steady stream of criticism from parents and educators.

Chief Academic Officer Shael Polakow-Suransky sat on a three-person panel titled “High-Stakes Testing 101″ hosted at The Brooklyn School for Collaborative Studies and The Brooklyn New School. The panel included two principals, Long Island’s Sean Feeney and Elijah Hawkes formerly of the James Baldwin School in Manhattan, who have publicly criticized the city’s and state’s use of testing data to measure student growth and evaluate teacher effectiveness. Hawkes was one of about 170 city principals to sign on to a petition Feeney authored against the state’s use of student test scores in teacher evaluations.

That system, in which student growth on standardized test scores count for at least 20 percent of teacher ratings, was officially signed into law last week in Albany.

Polakow-Suransky said the parents and principals were right to have qualms about the new system. He said the tests currently in use are imperfect and acknowledged, as the principals’ protest points out, the evaluation system allows for scenarios in which a teacher can have the full confidence of her principal yet still be rated ineffective if her students show zero growth.

“I agree with you that principals should not ever be in this situation where ultimately their judgment gets trumped by a mechanistic formula,” Polakow-Suransky said after Feeney raised the issue. “I think that’s an important thing that we need to look at as we work to implement this.”

But for the most part, the department’s second in command defended the city’s accountability system against concerns that test scores are being used inappropriately and that longer tests are negatively affecting schools’ curriculum and culture.

Audience members — who mostly included parents and teachers at high-performing schools in Brownstone Brooklyn — criticized the school progress reports, which Polakow-Suransky developed, and the “value-added” Teacher Data Reports released under a cloud of controversy last month.

Polakow-Suransky said a focus on test scores is far preferable to ignoring them and charged that student performance had been ignored until the Bloomberg administration took over the city schools.

Under the old Board of Education, he said, “you [would] see data on crime, you see data on enrollment levels, on school construction, on budget. But nowhere on those annual reports is there any discussion of student learning and whether or not kids are learning.”

He added, ”I think that the fact that we’re having a conversation about how to measure whether or not kids are learning in our schools is an important one.”

That was little comfort for parents who said they were so opposed to high-stakes tests that they were considering boycotting this year’s state exams.

Asked by one mother what the consequences would be for her son if he missed the state test, Polakow-Suransky said he did not have a clear answer but suggested that an alternative assessment, such as a portfolio of schoolwork, could be used to demonstrate proficiency. Already, schools can compile portfolios to argue that students who fail tests should not be held back.

“I imagine that getting no test score would be equivalent of getting too low of a test score, which would generate the promotional portfolio,” Polakow-Suransky told reporters after the discussion.

Through the discussion, he stressed the idea that test scores are never the only data point consulted when making decisions about students, schools, or teachers.

But according to parents at the event, that message has not always made its way to the field. One mother said she saw a sharp contrast between P.S. 8, the Brooklyn Heights school her son attends, and the Brownsville elementary school where she is a teacher. P.S. 8 teachers emphasize critical thinking and creativity, she said, but the school where she works does not.

“Our curriculum, as dictated by our principal, is all year long focused on test prep,” said the teacher, who declined to give her name or the school where she worked. “Since February 20, which is the day after we got back from break, every single day my students sit through two ours of testing.”

Polakow-Suransky said a curriculum that focused on drilling and test prep was unlikely to pay off in higher test scores. “It’s failed wherever it’s been tried,” he said.

The teacher interrupted him to say that hasn’t been her school’s experience, at least according to the metrics that Polakow-Suransky himself has engineered. “I should add that my school gets an A every year,” she said.