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.”