A recent article in Columbia University’s paper brings out the tensions over whether class size is an underacknowledged secret ingredient of the appeal of the charter school trend.

Leonie Haimson, executive director of Class Size Matters, a nonprofit that advocates for smaller class sizes in New York City, argued … “It’s great that charter schools have smaller classes,” she added, “but not at the cost of overcrowding public schools and denying the same opportunity to public school students.”