Conor P. Williams, Senior Researcher at New America’s Early Education Initiative, wonders if we can get beyond the  pro-charter/anti-charter rancor which lumps all charter schools into one meaningless category:

Truth be told, ethical arguments between supposedly “pro-” and “anti-” groups fall prey to the same pitfall as the empirical arguments: they obscure the essential heterogeneity of charter schools. Charters are diverse to such an extent that they almost cease to be a definable subset. For instance: charters are union-busting drains on public education — except when they’re founded and run by teachers unions. Charters are test-centric “drill and kill” factories full of aggressive, teacher-driven, “no excuses” pedagogy — except when they’re devoted to the Montessori method or discovery-based learning. Charters pretend that teacher quality is the primary variable affecting students’ academic trajectory — except when the charter is part of a community-wide organization fighting child poverty. Charters are proof that traditional public education is stultified by too much government regulation — except when they become entry points for bad actors to access and divert taxpayer education dollars to other purposes. Charters are proof that parent choice and market demand are enough to shutter bad schools without top-down accountability — except when ineffective, inefficient charters limp along despite strong evidence of persistent failure.  

In other words, charters differ by more than just their effectiveness at improving student academic outcomes.