Diane Ravitch, education historian and pointed observer of the American educational scene, came to Philadelphia last week to speak at a math teachers' convention.

She had read the Philadelphia School District's "Blueprint for Transformation," and she wasn't pleased.

"If you really want to improve schools, you do something about teaching and learning," Ravitch said. "This is all shuffling deck chairs on the Titanic."

Call it reform if you'd like, but what Philadelphia's plan really proposes is privatization, Ravitch said.

"Education has never been market-driven," said Ravitch, research professor of education at New York University. "What they're trying to do is impose a business model on education, and there's no evidence that it's been successful."

Ravitch, a former assistant secretary in the Department of Education under President George H.W. Bush, had been a booster of No Child Left Behind and standardized tests.

But she's taken a sharp turn from those views, and now believes that the American educational system is on a dangerous trajectory, with students reduced to test-takers and schools given away for business reasons, not because of what's best for children. Inequalities result, she says.

Ravitch scoffed at district officials' notion that "achievement networks" were a Philadelphia takeoff on a successful New York model.

When it decentralized, New York doubled its budget, "and the results haven't been unusually impressive," Ravitch said. "If you're going to say this is a bold reform plan, where's the evidence that it worked someplace else? And don't say New York City."

Later, on her blog, Ravitch wrote that "in the Philadelphia 'blueprint,' as elsewhere, there is always talk about evidence and research, but truth to tell, I couldn't find any in this plan."

The Philadelphia plan struck her as "deregulation, and we know how that worked out with the stock market."

To Ravitch, it's just "replacing one level of bureaucracy with another."