The charter school movement has been gathering steady steam since the late 1990s in New York City. Nearly 100 are in operation today, predominantly in parts of the city long-plagued by poverty and low academic achievement. Central Harlem's District 5 is no exception: 20 percent of local schools are charters. More are coming. New York State education leaders said in December that they support opening 200 new charter schools. Mayor Bloomberg's current five-year capital plan would allocate $200 million for the new charters.

Charter schools are public schools that are exempt from some of the constraints under which other schools operate. Their teachers typically do not work under a union contract, principals have more autonomy over curriculum and instruction and their students can be selected by lottery. (Most other public schools have open enrollment.)

Proponents contend the schools' ability to innovate produces better results. In a 2009 study of New York City's charter schools, Stanford University academic and charter advocate Caroline Hoxby concluded that charter school students make long-term gains that significantly narrow (but do not close) "the Scarsdale-Harlem achievement gap," Results like those have made charters increasingly appealing to policymakers from the left and right. President Obama's secretary of education, Arne Duncan, has called for a $52 million increase in charter school funding in the 2010 federal budget.

But the reports of success in the charter experiment have met with some skepticism. When the CREDO (Center for Research on Education Outcomes) institute, also based at Stanford University, analyzed data from 70 percent of the nation's charter schools, it said only a fraction, 17 percent, excel, while 37 percent post lower outcomes than do traditional publics. Reports from the New York City Department of Education's charter office say that charter students do not make as much academic progress each year as their peers in traditional public schools—and note the dramatic difference in high need populations between school models, with open-enrollment publics serving far more special needs students and English-language learners than the lottery admission charters.

The rivalry between the charter school and public school models is not abstract: It's a very real competition for teaching talent, students, attention, money and—in New York City, anyway—space. The Department of Education is locating more of the expanding universe of charter schools in public school buildings, cutting into space that noncharter kids use. `

The charter debate provokes philosophical questions too, says Pedro Noguera, executive director of the Metropolitan Center for Urban Education and an NYU professor. "The regimentation, the silence and the little emphasis on control concern me. Middle-class kids are never treated that way," he says. Many charters, including the Promise Academy, seek to cultivate "character" and mold behavior to more traditional, middle class standards—what some describe as a kind of paternalistic, top-down imposition of mainstream culture. "They are preparing kids to be followers, not leaders—to conform, not innovate," says Noguera. "I support what Geoff Canada is doing—his ambition, his dedication, his commitment. He is a sincere, dedicated individual. It doesn't mean that everything they do is right, though."