In 2013, the N.C. General Assembly implemented an A-F school grading system for all public schools in the state. Two years later, the N.C. Department of Public Instruction has released school performance grades for the first time. These grades reflect the performance of schools for the 2013-14 academic year.

The state has been designating schools based on student performance and academic growth for years. In the past, they assigned labels such as “school of excellence,” “school of distinction,” “school of progress,” “priority school,” and “low performing” to all schools in the state.

The problem is that most parents had no idea what those designations actually signified or the differences between them. Letter grades solve that problem by employing a scale familiar to all.

The grades are based on two measures: student achievement and academic growth. Eighty percent of the grade is based on student achievement measures, such as test scores, graduation rates, and advanced course participation.

The remaining 20 percent of the grade takes academic growth into account. Schools that do not have academic growth data are assigned a letter grade based solely on student achievement measures. Obviously, schools with no data will not receive a grade.

For the first year of the program (and, at this point, only the first year), N.C. DPI will use a 15-point scale. In other words, schools that obtain a score of 85 to 100 will receive an A, schools that score between 70 and 84 will receive a B, and so on.

Starting next year, the school grades will be based on a 10-point grading scale. Grades will likely drop for hundreds of schools next year simply due to this change.

N.C. DPI did an excellent job of disseminating background information and reporting the grades, which are available on the state’s School Report Card website. In addition to an overall grade, elementary and middle schools will receive separate grades for reading and math. Schools that earn a D or F are required to inform parents of that grade.

Even before they were released, a number of teachers, school administrators, and so-called education activists objected to the underlying concept. If you ask me, they “protest too much.” Parents in other states agree that school performance grades are a useful tool for evaluating a school, and most are aware that it is not the only way to determine school quality.

In addition, school superintendents warned parents that the school grades “do not tell the whole story” about the state’s public schools. To a certain extent, they are right, and that will always be the case.

But that fact does not mean that the school performance grades are not necessary. It simply means that, as they are currently designed, the grades may not be a sufficient representation of schools’ quality or performance.

If stakeholders desire a more nuanced grading system, then education officials should work with state legislators to add variables, include qualitative descriptors, or alter the student achievement and academic growth percentages to address their specific concerns. There is already some positive movement in that direction.

Sen. Josh Stein, D-Wake, recently introduced Senate Bill 30, a bill that would make academic growth account for 60 percent of the grade calculation. And we can learn a lot about best practices from states like Florida, which has had a school performance grade system in place since 1999.

In the end, all involved should remain focused on one laudable goal: maintaining a system of transparency and accountability for North Carolina’s public schools that is straightforward, fair, accurate, and widely accessible.

Interestingly, the school performance grades are pretty evenly distributed, although they do not quite correspond to a normal distribution. Just over 1,000 schools earned a C. Additionally, 582 earned a B, and 561 earned a D. At both ends of the spectrum, the state has 132 A schools and 146 F schools.

Compared to district schools, a higher percentage of charter schools earned an A or B. Overall, 5.1 percent of district schools earned an A, compared to 11.2 percent of charter schools. In addition, 23.7 of district schools earned a B, which was considerably lower than the 29.6 percent of charter school Bs. Unfortunately, a higher percentage of charter schools received an F this year.

So, where is the best school in the state? According to the school performance grades, the best school in the state is in Burke County. Burke Middle College was the only school in the state to score a 99.

A few schools were not far behind. Challenger Early College High (Catawba), Cato Middle College High (Charlotte-Mecklenburg), Isaac Bear High (New Hanover), and Raleigh Charter High School (Wake) scored 98s. High schools are overrepresented at the top because of the type of variables used to determine their grades.

Pundits, reporters, and elected officials will be slicing and dicing the data for weeks. Expect the same from yours truly.

Dr. Terry Stoops (@TerryStoops) is Director of Research and Education Studies at the John Locke Foundation.