Andrew Leigh's study on measuring good teaching

Study finds teacher performance judging feasible
AM - Monday, 21 May , 2007 08:13:00

Reporter: Gavin Fang

TONY EASTLEY: A new study has found that the test scores of schoolchildren can be directly linked to the performance of their teachers.

Australian National University economist, Andrew Leigh, has looked at the results of students over three years and found that the best teachers are twice as effective as the worst. He says it shows that teachers can be judged on their performance.

Dr Leigh spoke to our reporter Gavin Fang.

ANDREW LEIGH: So the study is looking at the differences between the best and the worst teachers, trying to look at whether teachers are basically all the same, or whether there's quite a large degree of dispersion.

It does this by looking at how the same child performs with two different teachers, or even three different teachers, and that way you can take out the effect of the child's family background, and all you're left with is the impact of the teacher.

GAVIN FANG: And what did you find?

ANDREW LEIGH: There's pretty substantial differences. A child working with a teacher in the top 10 per cent learns about twice as fast as a child learning with a teacher in the bottom 10 per cent.

GAVIN FANG: What role do demographics play in determining these results?

ANDREW LEIGH: Student demographics are huge and that's why doing the study in this way teaches you a lot more than if you look at a simple snapshot of a classroom. Looking at a snapshot of a classroom doesn't in fact tell you anything about teacher quality, but looking at how a child's test scores change over time really does tell you a lot more about teacher quality.

The demographic characteristics that I have, or the demographic characteristics of the teachers, it turns out that more experienced teachers do in fact do a little bit better. And surprisingly female teachers do slightly better in teaching literacy than do male teachers.

I don't find any impact of teachers having a master's degree on, any suggestion that those teachers do better on raising students' score. But all of those characteristics really explain very little of the differences.

What the study says is there's big differences between the best and the worst teachers, but it's difficult to explain those differences based just on age and experience.

GAVIN FANG: Have you got any idea where these better teachers are placed? Are they in the public or private school systems?

ANDREW LEIGH: Look, I'd love to be able to look at that, but again the confidential nature of the data prevents me from doing it. But it's a really important question. I mean, if we're currently assigning the best performing teachers to the most advantaged students, that's the opposite of a policy, of a way in which you'd do things if you believed in equality of opportunity.

GAVIN FANG: Why is a study like this important to do, do you think?

ANDREW LEIGH: Well, I think it's important for two reasons. First of all, it indicates that we can measure output rather than just focusing on inputs as a lot of education policies have tended to do.

Secondly, it indicates that the factors that we currently take into account in paying teachers are essentially just experience and also potentially qualifications, really explain very little of the variation between teachers.

There's hugs gaps between the best and the worst teachers. But currently, many of those high performers and low performers are being treated the same way by the system.

TONY EASTLEY: Economist Dr Andrew Leigh from the Australian National University, speaking to Gavin Fang.