How Can We Stabilize Our Teacher Corps?
I had lunch the other day with a friend who's still at the school where I used to teach. We counted how many new teachers have stayed at the school since we started there three years ago. As best we could remember, my friend is the only teacher from our “batch” returning next year. Three teachers from the following year (one of whom had previously taught at the school) are returning, and likely only two of this year's new teachers will be back.
Combining new teacher churn with persistent attrition from the more experienced ranks paints an ugly picture that's playing out in too many schools.
It's easy to fall into the trap of assuming that low test scores are the result of indifferent teachers just in it for the job security. Certainly this is the picture painted by some elements of the education reform movement. Too often, however, the problem is that there aren't enough veteran teachers.
In 2010, the National Commission on Teaching and America's Future released a report [slow-loading PDF; faster "preview" version here] examining changes in teacher experience. The past twenty years have seen the distribution of teaching age collapse from a bell curve to a flattened lump with two slight bulges—one representing the churning crop of new teachers, the other the last remnants of the Baby Boomer bubble. In 1997-98, the most common number of years of teaching experience was 15. By 2003-04 that had plummeted to 1, and it hasn't moved since.
This hurts student achievement. A 2009 paper [PDF] by Francis Huang and Tonya Moon reported that there's a very clear pattern connecting student gains on standardized tests to a teacher's experience teaching that particular grade (shuffling teachers from grade to grade kills the effect).
For the first 20 or so years of experience at a given grade level, student gains tend to increase each year. After about 24 years, the level of gains declines. However, the typical teacher with 30 years experience at a given grade level still gets gains similar to those of a teacher with 12 years of experience. (To see the graph, look at page 19 of the PDF linked above.)
Losing experienced teachers (or subjecting them to frequent changes of grade or subject) costs our students. Experience with a particular class is quite possibly the best way to increase teacher effects on student gains. That, unfortunately, is nowhere near the priority list of many self-described reformers. It's time to change the conversation.