Two weeks ago, Mayor Bloomberg and his schools chancellor, Joel Klein, cheered New York City’s fourth-graders for passing the statewide English test at the highest rate ever. Yesterday, standing in front of an array of colorful bar graphs at Tweed Courthouse, the “education mayor” and the chancellor jubilantly announced that public school students in the third, fifth, sixth, and seventh grades also shattered records this year, scoring at the highest levels since the city started administering standardized English and math exams six years ago.

Overall, the proportion of students in elementary and middle schools who passed the city’s English Language Arts exams this year shot up to 54.8% from 40.4%. Between 2000 and 2004, the overall passing rate on the tests for the third, fifth, sixth, and seventh grades had varied only between 39.0% and 40.8%.

In math, too, the improvement this year was dramatic, as 50.0% of the 300,000 students who took the exams passed, up from 42.5% last year and 37.4% the year before.

“Results were essentially flat and disappointing until this year,” the mayor said of the English results. “In short, this year, third-grade, fifth-grade, sixth grade, and seventh-grade students have recorded the largest one-year gains since the city started administering ELA and math tests in these grades. In fact, they’ve achieved the highest overall scores ever seen on these tests.”

When the results of the fourth- and eighth-grade statewide English tests were released last month, New York City’s progress mirrored dramatic leaps in performance throughout the state, leading some critics to question whether the gains were due to improvements at city schools or an easier test. These new tests were administered only to city children, so no such comparison was possible. Yesterday, some of the mayor’s critics questioned whether averages improved because of the test, the population of test-takers, or the quality of the instruction.

The mayor attributed the record gains directly to his administration’s efforts to reorganize the public-school system and to the new curricula and programs his administration implemented in the schools.

“We have streamlined the administrative structure of the school system; instituted a comprehensive curriculum in reading, writing, and math; taken strong actions to make our schools safe and orderly; and aggressively worked to bring parents in as full, active partners in their children’s education through the use of parent coordinators. We’ve made major investments in improving instruction in the classrooms. … Last year we also ended the discredited practice of ‘social promotion’ in the third grade. And we’re doing the same in the fifth grade this year,” Mr. Bloomberg said. “Our reforms are working.”

Of the 2,702 students who repeated third grade because they were held back under the mayor’s one-year-old plan to stop promoting failing thirdgraders, 62.1% scored at levels 2, 3, and 4 on this year’s math and English tests, according to the results released yesterday. About 275 of the students who scored at level 1, the lowest level, were designated as special-education students this year.

Another figure Mr. Bloomberg highlighted to demonstrate the success of his program is the results for the fifth-graders who attended the Saturday Academy, which was created this school year to help fifth-graders at risk of failure. The Department of Education said 42.5% of those students scored at levels 3 and 4, meaning they met or exceeded standards. In contrast, only 31.6% of the at-risk fifth-graders who were invited to attend the academy but did not enroll passed the exam. Mr. Bloomberg said that the 10.9-percentage-point difference demonstrates the value of the Saturday program.

He also said major gains in the fifth grade – jumps of 19.5 percentage points in English, to 68.8% passing; and of 15.2 percentage points in math, to 53.7% passing – showed that holding students to higher standards is working.

“It just goes to show that when you raise the requirements and when you hold people accountable, people perform better,” the former businessman said. “That’s true in every part of society. We will always work up to requirements we know we have to. That’s what’s so great about having standards. It makes people do more.”

As news of the results spread around town, union leaders, lawmakers, and the mayor’s political rivals praised students and teachers for the stunning gains, but some warned New Yorkers to question the record-breaking gains.

The president of the teachers union, Randi Weingarten, said this year’s results show that last year’s flat scores in reading were “an anomaly,” likely due to the “confusion of the school system’s reorganization.”

“This shows what can be accomplished when educators and administrators work together and build on past accomplishments,” she said. “We are happy that Mayor Bloomberg gives teachers credit for these increases. Now, it is time for him to negotiate a contract before the school year ends.”

The leader of the principals union, Jill Levy, said it’s unfortunate that New Yorkers cannot compare the performance of city students in the third, fifth, sixth, and seventh grades with the performance of students elsewhere in the state, but she praised her members for helping improve student achievement.

The chairwoman of the City Council’s Committee on Education, Eva Moskowitz, called the scores “encouraging” but questioned whether there was a relation between the huge increases in passing rates and the upcoming mayoral election.

“Because this is an election year, the mayor will be accused of manipulating the scores, and I think that he and the chancellor should immediately release the methodology and data that they used to satisfy themselves that this year’s test is comparable to last year’s,” she said in a statement. “They need to show parents that the tests were similar in difficulty and content, and that the scoring was done the same way as last year. Also, they should detail which children were exempted from the tests and what impact that had on the scores.”

The head of testing for the education department, Lori Mei, said the tests were comparable in difficulty to last year’s. The department wants the tests to be consistent so it can track student performance.

Spokesmen for CTB/McGraw-Hill, which developed the math tests, and Harcourt Assessment, which developed the English test, also said the tests were no easier.

“CTB/McGraw-Hill has verified the student and trend results for the NYC mathematics 2005 test (Form 7) using well-established procedures to ensure reliable and valid score results that are comparable over time,” the company’s spokeswoman, Kelley Carpenter, said in a statement. She said the company’s research scientists follow national standards, and the tests “undergo rigorous quality-control processes.”

A Harcourt spokesman, Mark Slitt, said the students might have scored better because of better instruction or studying harder, but he said: “The tests themselves are of comparable difficulty from year to year.”

Still, the mayor’s political rivals were unwilling to accept the scores at face value.

“This certainly has me suspicious,” Rep. Anthony Weiner, Democrat of Queens, said. “I’ll be honest with you. You have flat numbers throughout the Bloomberg administration and now, at election time, they’re spiking up.”

Another Democratic mayoral candidate, Fernando Ferrer, said he hadn’t reviewed the scores, but he said the parents, teachers, and students deserved the credit, not the administration.

The City Council speaker, Gifford Miller, who is also trying to unseat Mr. Bloomberg, said he doesn’t think the progress is enough.

“Half of the children in our public school system are still not meeting basic standards, and no one in a leadership position should be willing to accept that. I certainly do not,” he said.