To reduce the percentage of a teacher's "effectiveness" evaluation that must be based on student progress as measured by state test data (instead of other local and potentially more subjective measures) from 50 percent to 20 percent in "core" subjects, with the remainder based on local measurements of student academic progress, and delay full implementation until the end of the 2017-2018 school year. The original 50 percent of assessments based on state tests requirement was established by a 2011 law basing school employment decisions on these ratings.