as she has done many times before. The occasion this time is the NY Post making a bit issue of the supposedly worst teacher in the city. Linda has written on this subject, either by herself, or in conjunction with other experts on education, several times in the past few years.
Linda, who is a personal friend and professional colleague, has an important new piece on the subject of value-added methodology in Education Week, the most important single publication in the field of education, which you can - and should - read here.
Linda Darling-Hammond acknowledges that she - like many others, originally had high hopes for the use of value added evaluations of teachers. But now it is clear to her, as it is to many have examined it closely, that it does not live up to their hopes. As she writes (and you might want to follow the links)
I was once bullish on the idea of using “value-added methods” for assessing teacher effectiveness. I have since realized that these measures, while valuable for large-scale studies, are seriously flawed for evaluating individual teachers, and that rigorous, ongoing assessment by teaching experts serves everyone better. Indeed, reviews the National Research Council, the RAND Corp., and the Educational Testing Service have all concluded that value-added estimates of teacher effectiveness should not be used to make high-stakes decisions about teachers..
Please keep reading to understand WHY value-added should not be used for these purposes.
Let me quote the heart of this post:
First, test-score gains—even using very fancy value-added models—reflect much more than an individual teacher’s effort, including students’ health, home life, and school attendance, and schools’ class sizes, curriculum materials, and administrative supports, as well as the influence of other teachers, tutors, and specialists. These factors differ widely in rich and poor schools.Unfortunately, we have seen an increasing emphasis on Value-added as if it were some king of magic bullet.
Second, teachers’ ratings are highly unstable: They differ substantially across classes, tests, and years.
Teachers who rank at the bottom one year are more likely to rank above average the following year than to rate poorly again. The same holds true for teachers at the top. If the scores truly measured a teacher’s ability, these wild swings would not occur.
Third, teachers who rate highest on the low-level multiple-choice tests currently in use are often not those who raise scores on assessments of more-challenging learning. Pressure to teach to these fill-in-the-bubble tests will further reduce the focus on research, writing, and complex problem-solving, areas where students will need to compete with their peers in high-achieving countries.
But, most importantly, these test scores largely reflect whom a teacher teaches, not how well they teach. In particular, teachers show lower gains when they have large numbers of new English-learners and students with disabilities than when they teach other students. This is true even when statistical methods are used to “control” for student characteristics.
It is not.
Read Linda's article.
Pass it on.
Maybe it is not too late to save American public education, although I have my doubts.