Many people are extolling the promise of mayoral control as a way to improve student achievement in Rochester's schools. But author and education historian Diane Ravitch isn't among them.

The former assistant secretary of education to the George H.W. Bush Administration was in Rochester earlier this week to give a talk to the Rochester Teachers Association.

In a telephone interview prior to the event, Ravitch said she is not against mayoral control. But she doesn't agree that educational outcomes have greatly improved in New York City under Mayor Michael Bloomberg and Chancellor Joel Klein.

Even though the New York City model is often held up as a shining example of success by everyone from US Education Secretary Arne Duncan to Rochester Mayor Bob Duffy, Ravitch challenges the reliability of the city's test scores.

Her point is often confirmed, she said, by college educators like the one she met at a recent meeting. Students, the woman told her, ask all the time why they need remedial instruction. After all, they say, they had passing grades in English and they graduated from a New York City high school.

Parents, Ravitch said, have no voice in the school district or access to Mayor Bloomberg, and heightened accountability is a myth. In her book, "The Death and Life of the Great American School System," Ravitch describes mayoral control as an experiment in market-based education heralded by the business community and wealthy foundations like the Broad Institute. The one-time devotee of No Child Left Behind warns that high-stakes testing is not providing students with a good education. It is instead, she said, being used to erode the nation's public school system.

In her interview, Ravitch talked about mayoral control in New York City and its true costs and failures. The following is an edited version of that conversation.

CITY: Are you opposed to mayoral control period, or the type created under the first New York City law?

Ravitch: I'm opposed to the form of mayoral control in New York City, which has an absence of checks and balances.

Looking at test scores and graduation rates, there's disagreement about whether student achievement has improved under mayoral control in New York City.

Look at the remedial rate in the area's community colleges, which is 75 percent. If students have done so well, why do so many need remedial help on basic skills?

Here's the thing. Mayoral control by itself doesn't answer any important questions. You need to look at National Assessment of Educational Progress scores. At this point, the only reliable scores are the federal test scores because these tests are given to scientific samples of children in all 50 states. Nobody knows who will take the tests, so you can't prepare for them.

The test prep that New York City has invested heavily in actually corrupts the test itself. Chancellor Joel Klein always says they prep for the tests and that's why they do so well. But if you substituted a different test covering the same material, they wouldn't do well at all. That's how test prep corrupts the measure, because you're no longer measuring whether kids can read and do math. You're measuring whether they can pass the test that they were prepped for.

If you look at the NAEP scores and look at the cities that have mayoral control, some of our lowest performing cities have mayoral control. Cleveland and Chicago are prime examples of cities with mayoral control that are consistently at the bottom of the pack.

You've also stated that the tests used in New York have been "dumbed down." So is the praise heaped on New York City's scores questionable?

Of course. The passing marks on the state tests have been systematically lowered from 2006 to 2009. That's why we saw these press conferences in Albany announcing these dramatic double-digit increases.

They turned out not to be real because when you looked at the federal scores, there have been some gains in math, but no gains in reading. I don't think there have been gains in reading in New York State since 2005.

And I don't believe there has been a dramatic improvement in New York City's achievement or graduation rates, because we have seen a widespread use of something called credit recovery. Kids take a three-day course to make up for a semester or they present an independent project that nobody monitors. Principals indulge in this kind of thing to get kids to graduate and thereby raise the rates.

Now if you do believe the improvements are real, it should be noted that the school district's budget almost doubled. It went from $12.5 billion to $22 billion in just a few years. So if Rochester wants to do the full Bloomberg treatment, you should be prepared to double your school budget.

Rochester's mayor, similar to Chancellor Klein, argues that having one person in charge rather than a seven-member board provides greater accountability. What's your view?

It all depends on what actions he plans to take. If having an elected school board without mayoral control is wrong, why are Austin and Charlotte the best performing cities in the country? They don't have mayoral control.

You call the push for accountability a game of blame and punishment that achieves little. What do you mean?

When people ask who are we going to hold accountable, what they really mean is who are we going to punish.

In New York City, when they talk about holding the mayor accountable, how do you hold him accountable when he spent more than $100 million on getting re-elected to a third term? His opponent spent $10 million. If you can't hold the mayor accountable, how do you hold the chancellor accountable?

The state law that renewed mayoral control said that they had to have a public hearing before they could close schools. They had a public hearing and 3,000 parents, teachers, and students turned out. And they all testified, please don't close our schools. We like our schools. This went on until three in the morning. And then the panel voted overwhelmingly to close them. The hearings were pro forma.

That's what mayoral control means. It means the public has no voice.

You're familiar with Joe Viteritti's book, "When Mayor's Take Charge." He says that mayoral control creates the opportunity for the kind of bold leadership needed to turn around failing school districts.

I don't agree with him. Chicago wasn't turned around. Chicago was all about opening schools and closing schools. Opening, closing, opening, closing.

The last report out of Chicago said that all the gains that had been attributed to the Chicago schools were a result of lowering the passing score on the tests; the same as in New York State. It's the same old story.

We're back to the question of whether the data used is accurate.

Exactly. We have a situation here in New York City where the education system is being run by business people. The mayor is not an educator. The chancellor is not an educator. Both are relying on data, but the data is deeply flawed. They feel that if they produce the right data, everything is fine. Well, everything is not fine.

Chancellor Klein likes to say that he's leading the civil rights revolution of our time. But look at the percentage of black and Hispanic kids who are admitted into the city's selective high schools. It's plummeted.

There was a front page article in the New York Times last fall about a competitive high school that emphasizes math and science. Kids have to take an exam to get admitted. Five years ago, out of their entering class of 900 students, 83 were African American. In 2009, there were seven. The number of Hispanic students plummeted as well. The same pattern was repeated in all of the selective schools. Minority students weren't qualifying.

The Bloomberg administration acknowledges that lack of parental input has been a problem, and they say they have taken steps to correct it. Have they?

Parents are definitely out of the picture. Their voices are not considered. The philosophy of the mayor is that if you can choose your school, that's all you need to be concerned with. It's a consumer thing. If you don't choose to shop here, that's your privilege.

Are you against charter schools?

No. But I am against charter schools being used to dislocate and replace public schools. The New York City administration favors charter schools over regular public schools. I'm in favor of the original agenda for charter schools. They were intended to collaborate with public schools. They were supposed to be working toward a common goal: What's the best way to provide our children with a good education?

But we have a very aggressive charter sector in this city and state that's run, according to the New York Times, by a lot of hedge fund managers who think that a free market system is more favorable than a public education system. If we hadn't just witnessed the collapse of the stock market and watched these people getting fat off of selling people's mortgages, I would feel a little more sanguine about what these people are offering.

The Bloomberg administration closed its large, low-performing high schools and opened smaller theme schools, which you describe as misguided. Since Rochester's schools superintendent is embarking on a similar strategy, what should parents and the community know?

I'm not an advocate of large or small schools. Probably the ideal size of a school should be about 1,200 kids.

What large schools have to offer that small schools can't is advanced courses in almost anything, and special programs for foreign language learners to help them become integrated.

What's happened with the closing of the large high schools is that many special programs that serve communities with special needs get disbanded. The students who are low-performing get shut out and get shuffled from school to school because they are less wanted. They'll pull the test scores in that school down. And once you get the low-performing kids, you're targeted for closure.

The trade off is that in small schools you get intimacy. But you lose the enrichment that comes with large schools.

Rochester Mayor Bob Duffy often says that he can't tolerate the argument that children who live in poverty can't learn.

That all sounds very appealing, but there's a century of social science that says that the single best predictor of test scores is family income.

Why is it that affluent suburbs produce high test scores and poor inner city neighborhoods produce low test scores? If it were true that poverty is just an excuse, how come Arne Duncan wasn't able to overcome poverty in Chicago?