"Potential broader problems with charter school reporting"
From the GAO Report:
GAO was unable to compare ELL enrollment in charter schools to ELL enrollment in traditional public schools because Education’s only available data on school-level ELL enrollment were unreliable and incomplete. Specifically, for over one-third of charter schools, the field for reporting the counts of ELLs enrolled in ELL programs was left blank. These blank fields cannot reliably be interpreted to mean that the charter schools did not have ELLs enrolled.
Some charter schools with blank ELL counts were also missing data from other important datasets, such as those on school performance, which suggests potential broader problems with charter school reporting.