The
Washington Post’s The
Answer Sheet blog discusses the shortcomings of evaluating teachers using student
test scores. It cites a recent American Institute for Research report
on the New York State teacher evaluation model that found when the percentage
of a classroom's students with disabilities or in poverty increases, the
average teacher evaluation score decreases.
Add to this
a new survey of 500 New York principals regarding the “student growth score”
evaluation model. Seventy-three percent of principals surveyed felt that the
“ineffective” label assigned to some of their teachers was either a "not
very accurate" or an "inaccurate" reflection of that teacher
based on their observations and the performance of that teacher’s students.
In the
survey, some principals stated that next year they would reassign certain teachers
to less needy students so they could protect excellent teachers from an
ineffective rating. Others expressed concerns that excellent teachers would
choose to leave for schools or districts with less needy students to avoid the
risk of an ineffective label. This suggests that new teacher evaluation systems
may be discouraging teachers from taking the most challenging assignments and
thus decreasing the chances that needy students will get the best possible
teachers.