Many states rely on student growth measures to evaluate teachers; in Chicago, growth data accounts for 40% of a teacher’s evaluation, and in New York it’s 20%. The Massachusetts educator evaluation system minimizes the impact of value-added student data.

These measures, which have been flash points in negotiations between teacher’s unions and school districts in Chicago and New York City, attempt to capture how much each teacher has contributed to their students’ academic growth over the school year. The measures are then used to arrive at an Impact Rating of low, medium, or high for each teacher.

The Massachusetts system does not assign student growth data a percentage. In fact, these measures have no impact on teachers with performance ratings of Unsatisfactory or Needs Improvement. Value-added data are only used to determine whether teachers with higher performance ratings (Proficient and Exemplary) are placed on one- or two-year self-improvement plans. That’s it! For a graphic explanation, please view this slide from an ESE powerpoint: Student Growth and the Impact Rating