An Education Department study says the workload for secondary school teachers has "never been lighter" and efforts to reduce class size in hopes of spurring student achievement are probably misguided.

The study released Wednesday estimated it could cost up to $69 billion a year and require the hiring of 1 million new teachers to reduce the typical class size from 24 to 15 students.It suggested school reformers look for ways to help teachers do a better job of managing the children in their classrooms rather than "sink vast sums" into efforts to reduce class size.

The report, "Class Size and Public Policy: Politics and Panaceas," said efforts to boost students' test scores through smaller classes "will probably be a waste of money and effort."

The report was based on a review of past studies, not on any new classroom research.

There now are 24 pupils in the typical public elementary school classroom, down from 30 in 1961. In secondary schools, the typical class size is down from 27 to 22.

The report by Tommy M. Tomlinson of the department's Office of Educational Research and Improvement said, "Smaller classes will worsen the shortage of both teachers and classrooms."

"If teachers today believe that the number of students per class is too large and their workload too heavy, it is also true that the number of students they teach has never been fewer and, from that standpoint, their workload has never been lighter," it said.

The report noted several states, including Indiana, have made smaller class size in the early grades a key ingredient of their school reform efforts.

Chester E. Finn Jr., the assistant secretary of education in charge of research, said lowering class size has become "an ersatz reform goal around the country."

"There are a lot of better and less costly things you can do and get results," Finn said in an interview. "There's no question that good teachers in tiny classes are one of the reasons people pay for expensive private schools. But it's not a very prudent investment strategy if you're trying to improve the vast enterprise of American education."

The National Education Association, the 1.85 million-member teachers union, has a policy that states, "excellence in the classroom can best be attained by small class size," and it urges affiliates to "seek an optimum class size of 15 students."

Keith Geiger, the NEA's vice president, said in an interview: "It is very expensive to lower it to 15, but they continually use this rationale for doing nothing. We have elementary teachers out there sitting with 38, 40, 42 kids in their class. That's the sad part."

"We've got to move to less than 20-to-1 in the early elementary grades if we're ever going to expect to reach these kids so we don't have to spend all the money on remediation when they get into junior and senior high school," Geiger said.