Interaction effects and the Common Core
In science, statisticians must frequently grapple with interaction effects. Let's say, for example, that a scientist wants to study the impact of diet and exercise on lowering cholesterol. They have one group follow a low-fat diet, another a new running regimen, and a third group both. It's possible that both the diet group and the exercise group see a modest dip in cholesterol. But it's also possible that the third group will see a drop that is more than double what could have been achieved by diet or exercise alone?meaning that diet and exercise are ?interacting? in some way to affect cholesterol more powerfully. But, at what levels do participants see this interaction effect? When you follow a strict diet and exercise once a week? Twice? Etc.
In education, interaction effects are everywhere. As I've argued before, a strong curriculum implemented by skilled instructor often yields amazing results. The same curriculum implemented by a weak teacher may yield no (or negative) student achievement gains. That's because, as anyone who's ever worked in a school knows, outstanding student achievement results are the product of many different interacting elements within schools, not just of standards or curriculum alone.
For policy makers, it's challenging because no policy can control all of the (school-based) factors that will determine whether their programs succeed or fail in boosting student achievement.
So it is with Common Core. While the standards themselves are far more rigorous than what existed in most states previously, the one thing we've definitively learned from the past two decades is that strong standards alone will not ensure that all students learn essential content.
As we look to implement this next generation of standards, states, districts, and schools need to adopt a series of policies that will interact with the standards to drive student achievement.
To that end, I would argue that there are, at a minimum, two things that need to be in place for rigorous standards to drive student achievement: First, individual teachers must feel ownership over and be accountability to their students' achievement results. Second, teachers need to employ effective, data-driven instructional practices.
The challenge, of course, is that sometimes, policies are enacting to improve one area but that hurt another. For example, effective instruction is driven by good planning and curriculum. So it seems logical that handing teachers pre-planned and pre-packaged curricula would improve student achievement.
Unfortunately, mandating the rigid implementation of such resources from on-high impacts the ownership that teachers feel over their students' achievement results.
Similarly, holding teachers accountable only to student performance on standardized tests will inevitably hurt effective instruction by encouraging shortcuts, curricular narrowing, etc.
It's complicated?more complicated than some debates over education reform suggest.
So as states consider what state- and district-level implementation of the Common Core should look like, they should consider what combination of policies will create the conditions that will yield the most significant student achievement gains in the greatest number of classrooms. Otherwise, we will be like a guy who's trying to lower his cholesterol by running just far enough to make it to the next McDonalds.