In many circles, class size is considered as fundamental to education as the three R’s, with numbers watched so carefully that even a tiny increase can provoke outrage among parents, teachers and political leaders. Alarms went off in New York and California last week, as officials on both coasts warned that yawning budget gaps could soon mean more children in each classroom.
But while state legislatures for decades have passed laws — and provided millions of dollars — to cap the size of classes, some academic researchers and education leaders say that small reductions in the number of students in a room often have little effect on their performance.
At recent legislative hearings on whether to renew mayoral control of the New York City schools, lawmakers and parents alike have asked, again and again, why Mayor Michael R. Bloomberg and Chancellor Joel I. Klein have not done more to reduce class size. On Tuesday, the Education Department issued a report that found the average number of children per class increased in nearly every grade this school year.
“If you’re going to spend an extra dollar, personally, I would always rather spend it on the people that deliver the service,” Mr. Bloomberg said when asked about the report on Thursday, calling class size “an interesting number.”
“It’s the teacher looking a child in the eye, and teachers can look lots of children in the eye,” he added. “If you have to have smaller class size or better teachers, go with the better teachers every time.”
But Assemblywoman Catherine T. Nolan, a Queens Democrat who is chairwoman of the Education Committee, said that she routinely hears from middle-class parents who say they are leaving the city in search of intimate classroom environments where teachers can pay more attention to each student. The teachers’ union estimates that New York City’s classes have 10 percent to 60 percent more students than those in neighboring suburbs, and the highest average size of any school district in the state.
“I always thought more money and the mayor controlling the schools would give us smaller classes,” said Ms. Nolan, who has a son in public school. “I just don’t understand it, but they seem to be nostalgic for a time of larger classes.”
The debate has continued for decades, with some consensus forming that class size matters most in the youngest grades, and that the effects are most profound when there are fewer than 20 students in a class.
Dan Goldhaber, an education professor at the University of Washington, said the obsession with class size stemmed from a desire for “something that people can grasp easily — you walk into a class and you see exactly how many kids are there.”
“Whether or not it translates into an additional advantage doesn’t necessarily matter,” Professor Goldhaber said. “We know that teachers are the most important thing, but teacher quality is not stamped on someone’s forehead.”
A Tennessee study in the late 1980s, widely regarded as the most influential study on class size, found that in kindergarten through third grade, students in classes of 13 to 17, particularly poor and minority students, performed better than those in classes of 22 to 25. In some cases, the benefits extended through high school.
But since then, as many states and school districts have rushed to reduce class sizes, usually to the low 20s, student achievement has not consistently improved markedly.
In California, a 1996 law provided schools with an extra $1,000 in state money for every student in the earliest grades whose classes had 20 or fewer students. The state quickly hired 28,000 new teachers, but many of them lacked experience or education credentials; a 2002 study by the Public Policy Institute of California found that the best-qualified teachers fled poorer urban schools as the extra funds created jobs in wealthier areas, and that children who were in smaller third-grade classes did not have higher scores on fifth-grade tests.
In New York City, an Education Department comparison over the last two years between school report-card grades and average class size has found little correlation; in many cases, schools with better grades have bigger classes.
Still, some researchers argue that reducing class size is a concrete and worthy goal.
“We can say we just want more good teachers, which would be great, but that’s a policy that we just don’t know how to do yet,” said Diane Whitmore Schanzenbach, an education policy professor at the University of Chicago. “The nice thing about reducing class size is that it makes teachers happy in their own right and it’s the one thing that we know how to do.”
In New York, class sizes increased despite an infusion of $150 million in state funds last year earmarked specifically to reduce the numbers of children in each room. Chancellor Klein initially bristled at the restrictions state officials put on the money, but Albany would not release the funds until the city submitted a plan to bring class sizes down further. Last week, the city said it might have to adjust that plan to “reflect the worsening economic climate.”
Christopher Cerf, the deputy chancellor in charge of human resources, said the increase in class sizes this school year could be attributed to principals who determined that their money was better spent elsewhere and that the focus on class size was wrongheaded. “People think that this is the keys to the education reform kingdom here, but that is simply not the case,” he said.
Garth Harries, who oversees class size for the city, said that better schools often end up with larger classes as more and more parents want to send their children to places with successful track records. “It’s a complicated trade-off,” he said. “Would you end up giving fewer families access to those schools?”
But Leonie Haimson, the executive director of an advocacy group, Class Size Matters, and a frequent critic of the administration, scoffed at the suggestion that parents were happy with larger classes, saying, “The department is just trying to escape accountability.”
“Most of our elementary schools are zoned for a neighborhood, and to blame it on parents is absurd,” she noted. “You have more than 40 percent of students attending schools that are overcrowded. That’s not something they choose.”Javier C. Hernandez contributed reporting.