ATLANTA (AP) — Gov. Nathan Deal has signed a bill to standardize annual evaluations for Georgia teachers and principals based, in part, on student performance.

Deal signed the legislation without comment on Tuesday, which is the last day for bill signings.

The evaluation system is based on a pilot program launched a few years ago with federal funds and is expected to be implemented in every district by the 2014-15 school year.

Georgia is the latest state to move toward a standardized evaluation system as advocates around the country have pushed for the change. In Georgia, evaluations will be based 50 percent on student growth and achievement and 50 percent on other factors, including classroom observations and student surveys.

State education leaders say the system is needed to ensure teachers receive consistent feedback.