Updated data show class sizes are up, especially in early grades

Class sizes and student-to-teacher ratios went up this year, especially in the elementary school grades, according to data the Department of Education released today. This is the first time the Department of Education has reported an increase in class sizes since Mayor Bloomberg took control of the schools in 2002.

School officials blamed the economy for the rising figures, which come despite millions of dollars poured into class-size reduction over the last year. In a release, officials said budget cuts have prohibited some principals from hiring new teachers.

The data show that classes are slightly less crowded than a preliminary data set released to the City Council late last year suggested, but still more crowded than they were last school year. The average third-grade class, for instance, now has almost 22 students, up from 21 last school year. The biggest increases in class size came between kindergarten and fourth grade, where research is clearest about the benefits of reduced class sizes.

The average class size in high school is also up, to 26.2 from 26.1 last year. The department’s presentation argues that the change is due to a new form of reporting. Some classes with more than one teacher in a single room used to be treated as two separate classes, but this year the department counted them as one. Under the old form of reporting, the average high school class size would have dropped to 25.6, school officials said.

The rising class sizes come against a backdrop of big investments by the state into reducing class size. The DOE, in its release, says that schools where reducing class size was a high priority have seen lowered figures.

We’re still working on a deeper analysis. While we do that, please feel free to peruse the release — and send us tips for questions to ask.