Nearly 2,700 New York City students were wrongly told in recent weeks they were not eligible for seats in public school gifted and talented programs because of errors in scoring the tests used for admission, the Education Department said on Friday.
The company that both created and scored the tests, Pearson, has apologized for the mistakes, according to the department, which is now scurrying to notify parents that pupils originally locked out of the coveted programs are instead able to apply for seats.
Updated scores will be distributed within 10 days and the deadline for applying to gifted programs, originally Friday, will be extended to May 10, the department said. Only six students were incorrectly deemed qualified for the gifted programs, but they will not lose their eligibility, the department said.
All told, 4,735 students -- or 13 percent of all those in kindergarten through third grade who sat for the tests -- were affected by the errors, said Erin Hughes, a spokeswoman for the Education Department. Of those, 2,698 are newly eligible for seats in districtwide gifted programs, meaning they scored at or above the 90th percentile.
The other 2,037 will be told they are now eligible for one of the city's five more competitive "citywide" gifted programs, open to those at the 97th percentile or higher. Those students had been erroneously told they were eligible only for the district programs.
In a terse statement, Dennis M. Walcott, the schools chancellor, said the errors made by Pearson were "unacceptable." The company also designed the state standardized tests being administered to students this month, and has developed new curriculums that have been endorsed by the city's Education Department.
"Pearson has an established record in this field and we depend on its professionalism and deep capacity to deliver for the public," Mr. Walcott said in his statement. "But in this case, they let our children and families down. I have told the company's officials in no uncertain terms that I expect this will never happen again."
In a statement, Scott Smith, the president of learning assessment for Pearson, said "the fact that these errors occurred is simply unacceptable to Pearson as we fully understand the importance of accurate scoring."
"It is clear that we had a breakdown in our processes and we are conducting a complete, extensive investigation of every step," the statement continued.
Because of the mistakes, the city will withhold $500,000 from Pearson's contract, which is worth $5.5 million over three years and is in its second year, Ms. Hughes said. Roughly $80,000 of it will go to pay for "communication and outreach" to families, including placing calls to them over the weekend, she said.
Even before the error, the number of students qualifying for gifted seats -- 9,020 -- was far higher than the number of seats. The new number is more than 11,700. The competition is most acute for the citywide programs, where only several hundred seats are available.
"It's unfortunate, but this happens," said Donna Taylor, the principal of the Brooklyn School of Inquiry, a citywide program. "There are a ton of people it has unfortunately affected."
Besides increased competition for the seats, the higher number suggests that the city has been unable to control the explosive growth in high test scores, which coincided with the growth in test preparation services. Last year, 9,644 students qualified.
The tests this year, which consisted of two parts delivered in one sitting, were revised to make them less susceptible to preparation, which education officials said would also help increase the chances that children from poor backgrounds would gain seats.
Shael Polakow-Suransky, the chief academic officer for the Education Department, said further study was needed to understand what factors could be causing the increase. He said the goal of the new assessments was not to reduce the number of eligible students, but to do "a better job of identifying kids' giftedness without respect to whether they had prior academic preparation."
Critics of the Bloomberg administration seized upon the mistakes. The teachers' union president, Michael Mulgrew, remarked that the Education Department "blames the testing company and tries to bury the announcement on a Friday afternoon." Public Advocate Bill de Blasio, a mayoral candidate, said it was time for the department to "reassess its relationship with the company."
The errors were discovered when two parents, one a statistician, complained that their children had been incorrectly scored, the department said.
According to Pearson, three mistakes were made. Students' ages, which are used to calculate their percentile ranking against students of similar age, were recorded in years and months, but should also have counted days to be precise. Incorrect scoring tables were used. And the formula used to combine the two test parts into one percentile ranking contained an error.
Earlier this week, the department said that score reports for 400 students had been lost, but that those tests had been found and were being scored.
One parent, Rena M. Ismail, 36, who had been told that her 5-year-old son, Hyder, was not eligible for a gifted seat, said the department informed her that her son had scored in the 89th percentile, when, by her math, he was in the 91st.
"I knew he got it," she said. "I could see it. They told me I was mistaken.
"I am an educated person. I know how to add and multiply, and I knew he got in by his score sheet."
Kyle Spencer contributed reporting.
Correction: April 19, 2013, Friday
This article has been revised to reflect the following correction: An earlier version of this article misstated who said that the goal of the new assessments was to do "a better job of identifying kids' giftedness without respect to whether they had prior academic preparation." It was Shael Polakow-Suransky, the chief academic officer for the Education Department, not Public Advocate Bill de Blasio.
This article originally appeared in The New York Times.