Using Student Test Scores to Fire Teachers: No More Reliable Than a Coin Toss
By Elizabeth Hanson M. Ed. And David Spring M. Ed.
In this report, we will explain why Washington State legislators should protect fair evaluations of our teachers and principals by opposing the use of unreliable student test scores to make decisions about teachers and principals. We therefore should oppose Senate Bill 5748 and House Bill 2019 which would unfairly require the use of student test scores to evaluate teachers and principals.
Public school teachers and principals deserve fair treatment on important decisions about who should be retained and who should be fired. They should not be fired based on student test scores because the variation in student test scores is random. It is no more reliable than a coin toss. How wise would it be to fire doctors or lawyers based on a coin toss? Heads they stay. Tails they go. Imagine what this would do the moral of staff who had also most no control over whether they stayed or were fired. In this report, we will look at the scientific research (or lack of it) on using student test scores to evaluate teachers.
What is Value Added Modeling (VAM)?The idea behind value added modeling is that you add up all of the high stakes test scores of a teachers students and compare them to their previous year’s test scores. Teachers whose students gained the most are rated as good teachers (they added value to their students). Teachers whose students gained the least are rated bad teachers and are fired.
There are numerous flaws with the using VAM to fire teachers.
First, VAM scores are unfair to teachers working with students from lower income families. Students from higher income homes gain the most on high stakes tests because they did not have to deal with outside problems like living in a homeless shelter. So VAM results in firing teachers in high poverty schools.
Second, VAM scores are not reliable. Because students assigned to any given teacher have backgrounds that vary greatly from year to year, the value added number assigned to a teacher varies greatly from year to year. A teacher rated as one of the best one year under VAM is likely to be rated one of the worst teachers the next year.
Third, VAM scores are not an accurate measure of student learning. High stakes multiple choice tests only Using Student Test Scores to Fire Teachers: No More Reliable Than a Coin Toss - Living in Dialogue: