NEW YORK - Starting next school year, the way New York City evaluates its public school teachers will be undergoing an overhaul.

New York's Department of Education has replaced its teacher evaluation system with a more in-depth evaluation. The new evaluation rates teachers as highly effective, effective, developing, or ineffective.

Teachers' grades will be 40 percent based on the student performance of a teacher's classroom, including the results of state exams and tests administered by the school. The remaining 60 percent will be calculated based on in-class observations by the school's principal.

The state's education commissioner says the new system will make it easier to weed out bad teachers and help struggling educators improve.