Virginia Gov. Robert McDonnell is greeted by supporters as he makes his way into the house chamber to deliver the State of the Commonwealth Address at the State Capitol in Richmond, Va. on Wednesday, January 9, 2013. (Bob Brown/Richmond Times-Dispatch via AP)

To simplify an ever-growing list of school rankings, Virginia lawmakers have approved a new way to rate the state’s schools, and it’s borrowed straight from teachers’ grade books: A to F letter grades.

Gov. Robert F. McDonnell (R) championed the A to F scale as a simple way to bolster accountability.

“When children come home with report cards, parents can clearly see how well they are doing and where they are in need of improvement,” McDonnell said in a statement. “This legislation brings that same idea to school performance.”

McDonnell and state legislators believe that a familiar grading system will allow parents to easily understand a school’s performance, while giving schools definitive targets for improvement, similar to a concept introduced in Florida more than a decade ago.

Though the Board of Education will not begin giving grades until fall 2014, some educators are already concerned that the new system will oversimplify the strengths and struggles of individual schools.

“We don’t give children one grade,” said Steven R. Staples, executive director for the Virginia Association of School Superintendents, which opposed the bill. “They get a grade in history and in English and in math. If you go to the Virginia Department of Education Web site, there are probably 200 indicators that reflect” a school’s performance. “We don’t know how that is going to be boiled down to one grade.”

Lawmakers spent the final week of the session trying to agree on a formula for the grades. They ultimately decided to use a combination of existing state and federal rating systems based on test scores and measures of a school’s improvement over time.

To earn an A, schools must be fully accredited by the state, achieve at least a 25 percent advanced proficiency pass rate on state tests, and meet all federal benchmarks for testing. B-rated schools would be fully accredited but fall short of the advanced proficiency pass rates. Schools would receive a C grade if they have been accredited with a warning in one subject area. A D school would be accredited with warning in more than one subject area or fall short of target graduation rates. F schools would be those denied accreditation or in the process of a government-mandated overhaul.

The state must also develop a new tool to measure how a school is improving before the first grades can be calculated. Lawmakers insisted on this provision so that the scale does not automatically disadvantage schools that serve higher-poverty students or more English-language learners.

Letter grades were first assigned to schools in Florida under Gov. Jeb Bush in 1999. Since then, 10 other states and New York City have rolled out an A to F school rating system.

Bush helped McDonnell promote the plan in a town hall-style conference call early this month. He said the approach spurred Florida schools to strive for better grades. Between 1999 and 2012, the number of A and B schools rose from 616 to 2,220, according to the Foundation for Excellence in Education, a group Bush founded to promote his vision for education reform. Critics have charged that improvements in Florida were the result of multiple changes to education funding, governance, and curriculum.

Preliminary analyses show that the vast majority of schools in Northern Virginia are on track to earn A’s and B’s. At least one school, Jefferson-Houston School in Alexandria, could earn a failing grade unless it charts significant improvement during the next year. It is also targeted for a possible state takeover.

Virginia already publishes an annual school-by-school “report card.” The 20-plus page report includes detailed standardized test results broken down by grade, subgroup and subject, as well as teacher education attainment levels and licensure status, student graduation rates and the number of safety violations or violent offenses that occurred on campus.

Some worry the letter grades could discourage people from delving into the details about their school’s performance, which would allow them to discover how different groups of children are performing.

“More information is still better,” said Michele Menapace, past president of the Fairfax County Council of PTAs. She said she’s afraid the grading system could roll back accountability by masking inequities between students.

The Virginia Department of Education already has a rating system, developed in the 1990s, that deems schools fully accredited, accredited with warning, or denied accreditation, based in part on standardized test performance.

Federal regulations in the past decade have brought additional labels for schools that failed to meet testing benchmarks known as “Adequate Yearly Progress.” And some low-performing schools undergoing interventions are now called “priority schools” or “focus schools.”

Del. Thomas A. “Tag” Greason (R-Loudoun), who sponsored the House bill to create the A to F scale, said the new system will not get rid of any labels, but it will give parents a way to more easily evaluate a school’s performance.

“We are not using code words, we are using words that people understand,” Greason said.