In the United States there are now 5,042 charter schools serving 1.5 million students in 39 states and Washington, D.C. Although they serve only a fraction of the nation's public school students, charter schools have seized a prominent role in education today. The question of whether charters or traditional public schools do a better job of educating students is still open to debate. The research is highly mixed due the complexities of comparison and wide performance differences among charters.
Charter schools are by definition independent public schools. Although funded with taxpayer dollars, they operate free from many of the laws and regulations that govern traditional public schools. In exchange for that freedom, they are bound to the terms of a contract, or "charter," that lays out a school's mission, academic goals, and accountability procedures. The average charter school enrollment is 372, compared with about 478 in all public schools. Researchers have linked small schools with higher achievement, more individualized instruction, greater safety, and increased student involvement. With their relative autonomy, charter schools are also seen as a way to provide greater educational choice and innovation within the public school system. Another attraction of charter schools is that they often have specialized educational programs. Charters frequently take alternative curricular approaches, emphasize particular fields of study or serve special populations of students. That growth of charter schools has been particularly strong in cities. More than 55 percent of public charter schools were in urban settings. Some charters have high concentrations of minority students because demand for schooling alternatives is highest among such students, whom they say are often poorly served by the traditional public school systems. Lastly, another positive argument for charter schools is that they improve the existing school systems through choice and competition.
However, there are some criticisms of charter schools. There is a high variability in the quality and success of charter schools across the nation. A high-profile report from the American Federation of Teachers (2002), for example, argued that many charter school authorizers have failed to hold the administrators and teachers accountable, leaving some students to languish in low-performing schools. Another concern of critics is that charters are more racially segregated than traditional public schools, thus denying students the educational "benefits associated with attending diverse schools". Skeptics also worry that charter schools unfairly divert resources and policy attention from regular public schools.
Taken together, studies about charter schools are inconclusive and have mixed results. Studies by the Goldwater Institute and California State University-Los Angeles found that students in charter schools show higher growth in achievement than their counterparts in traditional public schools. However, another study by the Institute of Race and Poverty at the University of Minnesota Law show that after two decades of experience, most charter schools in the Twin Cities still underperform comparable traditional public schools and are highly segregated by race and income.