The document discusses plans for evaluating teachers' impact on student learning in the 2014-2015 school year and beyond using various measures of student growth, including DDMs (District-Determined Measures) and MCAS SGP (Student Growth Percentiles). It provides examples of potential DDMs and processes for setting performance parameters. Districts will have professional judgment in determining overall impact ratings based on multiple measures. The Massachusetts Department of Education expects districts to refine their use of DDMs over time through continuous improvement.