Students First - Why an effective teacher matters: A Q & A with Eric Hanushek

Meet Eric Hanushek, who is a senior fellow at Stanford University’s Hoover Institution and an expert on education policy. He was the first scholar to measure the effectiveness of a teacher based on the learning gains of his or her student. You may have also seen him in the movie, “Waiting For ‘Superman.’” Hanushek was kind enough to answer a few of our questions.

StudentsFirst: What is an effective teacher?

Eric Hanushek: My definition is someone who consistently gets above average learning gains out of her class. An ineffective teacher is one that gets consistently below average learning gains out of her class.

SF: Why is it so important to identify and value effective teachers?

EH: For a long time, we’ve tried to find out what it is about schools that leads to higher achievement of kids and whether schools can be a good instrument in closing achievement gaps. That research has gone on now for over 40 years and my summary of it is pretty simple: Good teachers are the one resource that are important. Yet we don’t have any descriptors of what a good teacher is. While some teachers are much more effective than others, we can’t necessarily identify what it is about them—is it their experience, their training, their personality?

SF: In his State of the Union address, President Obama recently called for more young people to go into teaching. Do you agree?

EH: We need more good teachers but not necessarily more teachers generally. Going back to the research, it’s really hard to predict who’s going to do well in a classroom until they’ve actually been in a classroom. We should bring more people in, but make serious decisions based on their performance in the classroom about whether they should continue teaching or go and do something else.

SF: How is it is that an ineffective teacher for only one or two years can permanently derail a student’s academic progress?

EH: Let’s say in elementary school, you have one bad teacher. It’s 1/12th of a student’s education. If at some point you get a bad teacher, that puts you back, and a few bad teachers can put you quite a way’s back—so much so that you might have trouble catching up. The difference between a good and a bad teacher is one year of learning in an academic year. A good teacher can get 1.5 years of learning growth; a bad teacher gets .5 years of learning growth. If you get a few bad teachers in a row, a student’s life is altered dramatically.

SF: Can you describe how removing the low-performing teachers in a school winds up helping out all kids in that school?  

EH: Teachers are faced with classes that are very heterogeneous—some students are very behind and some students are way ahead. Good teachers have a way of handling that, but it takes some skill. The future of the school is hurt because you mix these students up and when paired with a bad teacher, they end up dragging everyone to average.

SF: Can all kids do well with an effective teacher?

EH: Effective teachers have been shown to help all kids in a class. It’s not to say that everyone is going to end up at the same level achievement, but we could improve learning if we make sure that there’s an effective teacher in each classroom.

SF: Can you please tell us a little bit about your forthcoming paper, to be published in June of this year, on the economic value of having a good teacher (or the cost of having a bad one)? The numbers are pretty astounding. 

EH: As an economist, what I tried to do was to to translate into an economic value the result of having a more or less effective teacher. If you take a teacher in the top quarter of effectiveness and compare that with an average teacher, a teacher in the top quarter generates $400,000 more income for her students over the course of their lifetime. That’s the good part. The bad part is the teacher in the 25th percentile, who causes  $400,000 in lost future income from that same class of 25 students, again compared to an average teacher. If you eliminate the bottom five percent of teachers in terms of effectiveness, or if you replaced five to eight percent of the worst teachers with an average teacher, U.S. achievement would rise to somewhere between Canada and Finland. A small number of teachers has a really big impact on the achievement of kids. But even at half of these numbers, the stakes are so large that we should be willing to undertake more radical change in our schools to bring about much higher achievement.

SF: After your appearance in the documentary “Waiting for 'Superman,'” have you been recognized in the grocery store?  

EH: I only had a cameo role, not Michelle Rhee’s or Geoffrey Canada’s part. Academics recognize me, but no one else.