With the news that the Obama campaign aims to double federal dollars for charter schools in concert with the McCain camp's established charter-school support (along with its concerted push for public-school vouchers), more attention is being focused on charters as alternatives to failing mainstream schools. Charters are fairly young institutions -- the first charter school in the U.S. opened its doors in 1992 in Minnesota -- but 4,300 more have debuted in the years since, and a new report by Education Weekpredicts an "acute shortage of leaders" -- to the tune of up to 20,000 new principals -- in response to the "unprecedented scale-up" in charter school growth. Charter school leaders tend to be younger and less experienced than principals of traditional public schools; nearly 60 percent have less than five years experience as school leaders.

Lumping all charters under one expansive umbrella risks oversimplifying the issue: For starters, some are run by veteran administrators, others by mission-driven idealists; some are sponsored by profit-making business entities and others by non-profit philanthropic or community-based institutions; and because most do not use union teachers, there's  enormous variability in pay, hours, and what's expected on the job. Philosophically, charters can be ultra-structured and traditional, as many are, or more progressive. So while it's convenient to talk about charters as a single bloc, it's important to realize the variability in each school's mission, staffing, teaching practices, and the community it serves.

Charter schools have become a fixture of the public-school landscape. Their exponential growth gives some serious pause, but many families find much to praise, as evidenced by jammed lotteries for prized schools. Yet whether charters truly serve all the city's students, or only certain swaths of historically undeserved communities, remains an open question. And given the location of the 18 charters opened by the DOE this fall, it's one that won't likely be answered anytime soon.