Mayor Michael R. Bloomberg, while congratulating traditional district schools for making improvements on state test scores, on Tuesday reiterated his support for more charter schools.
"I think they demonstrate again and again and again that that model gives superior results," Mr. Bloomberg said at a news conference at the Tweed Courthouse, where he discussed the state test results.
For the third year, the city's charter schools outperformed traditional public schools in math and English, and the spread in results between the two groups has increased.
In math, 72 percent of charter school students passed the state tests this year, compared with 60 percent of traditional public school students. In English, 51.5 percent of charter school students passed this year's tests compared with 46.9 percent of traditional public school students. (About 30,000 charter school students took the tests; 400,000 students took the tests in traditional public schools.)
"What we're seeing, and what we've seen all along," said James Merriman, chief executive officer of the New York City Charter School Center, "is that the longer school day and longer school year that characterizes charter schools, as well as simply a focus on instruction and the sense of having a schoolwide culture that everyone buys into, results in these kinds of achievement scores."
Critics of charter schools argue that charters attract some of the best students from the community, while enrolling far fewer students with special needs and English language learners than do traditional public schools.
Mr. Merriman said that he understood these concerns, and that demographics do matter when discussing data.
But with that in mind, he said, the fact that charter school students have improved by about nine percentage points on both the English language arts and math tests since 2010 "is cause for optimism in the charter sector."