Errors were made in calculating the “value added” scores of 10 percent of the District of Columbia teachers who were evaluated using that model for the 2012-13 school year.
In total, 22 teachers received a lower rating than they should have, and 22 received a higher rating, according to the school district. Although the district employs about 4,000 teachers, only 440 were evaluated on a model that counts student test scores as a significant factor.
As a result of those miscalculations made by Mathematica Policy Research, one teacher was fired. District officials say they are attempting to reinstate that teacher.
A version of this article appeared in the January 08, 2014 edition of Education Week as D.C. Discloses Mistakes in ‘Value Added’ Scores