The Stability Of Ohio’s School Value-Added Ratings And Why It Matters
I have discussed before how most testing data released to the public are cross-sectional, and how comparing them between years entails the comparison of two different groups of students. One way to address these issues is to calculate and release school- and district-level value-added scores.
Value added estimates are not only longitudinal (i.e., they follow students over time), but the models go a long way toward for differences in the characteristics of students between schools and districts. Put simply, these models calculate “expectations” for student test score gains based on student (and sometimes school) characteristics, which are then used to gauge whether schools’ students did better or worse than expected.
Ohio is among the few states that release school- and district-level value-added estimates (though this number
