A new report concludes charter schools in the Twin Cities are failing to perform as well as traditional public schools, and they're more segregated. Researchers from the Institute on Race and Poverty at the University of Minnesota compared test scores at public and charter schools in the Twin Cities. The study found charters usually score worse than traditional public schools that have similar percentages of students in poverty. It also found more charter schools have opened that serve only a narrow student population, such as all-black and all-white schools. But Mo Chang, the principal of a mostly-Hmong charter in St. Paul, says it's not segregation if parents choose to send their kids there.