(RALEIGH) -- North Carolina's law on charter schools received a grade of "C" and ranked 29th among the states. That is according to the Center for Education Reform.

The Center's director Jeanne Allen said raising the cap of charters did not go far enough.  She also said the approval process for such schools needs to be changed.

"It limits the approval to the State Board of Education which is not very inviting when it comes to applications and school districts have not been very positive in helping encourage people and groups to actually apply," said Allen.  She added that other states such as Indiana and Minnesota provide multiple ways for charters to get approved.

Charter schools operate separately from traditional public schools, but they receive government funding.  The Center for Education Reform is a national education reform advocacy organization.