Great teachers create great value:

Did you have a favourite teacher when you were at school?  At least one who was special and made a difference to the direction of your life? 

Chances are you will say yes.

A great teacher inspires, informs and influences. But how do we determine what is a ‘great teacher’?

A recent study by three academics from Harvard and Columbia universities sought to answer this question by showing that one of the key factors - but with the caveat that it is not the only factor - in identifying such teachers are test scores.

The measurement of teaching quality is a policy that both the Howard and Rudd/Gillard governments have pursued in recent years. Last year, Education Minister Peter Garrett announced that from 2013 ‘performance pay’ will be introduced for teachers in Australia that will assess a teacher’s performance on a “range of evidence” including:

• lesson observations
• parental feedback
• teacher qualifications and professional development undertaken, and
• student test scores including NAPLAN and other information that can show the ‘value added’ by teachers.

It is the latter which is one of the more controversial elements of the performance pay policy. A teacher’s value-add is defined as the average test score for his or her students adjusted for differences across classrooms and student characteristics. Supporters argue that the value added approach leads to improved student achievement, while critics argue that test scores are a poor measure of a teacher’s true quality.

The Harvard/Columbia research tracks 1 million children in the USA from 4^th grade through to adulthood. In summary, they found by looking at standard measures of value add using different methods, that test scores rise “immediately” when a high value added teacher joins a school, and test scores fall when a high value added teacher leaves. The test scores change only in the subject taught by the individual teacher, not in other subjects by the same students.  Further, the size of the change in test scores correlates with the study’s prediction based on the teacher’s value added assessment.

The authors of the study – Raj Chetty, Professor of Economics and John N Friedman, Assistant Professor of Public Policy both of Harvard, and Jonah E Rockoff, Assistant Professor of Finance and Economics at Columbia – further examined whether high value add teachers have a long term impact on their students.

In a word, yes.  According to Chetty, Friedman and Rockoff, “teachers’ impacts on students are substantial”. They found that students of higher value added teachers are:

• more likely to pursue further education beyond school
• earn higher salaries
• live in better neighbourhoods
• save more for retirement, and
• less likely to have children as teenagers.

Their modelling shows that replacing a teacher whose value add is in the bottom 5% with a teacher of just average quality would generate substantial additional lifetime earnings, and that the impact on earnings is similar in percentage terms for students from low and high income families. They estimate that parents should be willing to pay roughly 25% of their child’s income at age 28 to move their child from a teacher whose value add is below average to one whose value add is above average just in one year.

But while all this may appear to be good news for the advocates of using test scores such as NAPLAN as an indicator of a teacher’s value add, the trio also warn that more work is needed to determine the best way to use the value added approach in education policy terms.  They write:  “For example, using value added in teacher evaluations could induce counterproductive responses that make value added a poorer measure of teacher quality, such as teaching to the test or cheating.”

The Australian Government’s response to this is likely to be that their performance management framework for teachers takes account of this difference of opinion on value add by including other measures such as parental feedback and lesson observations. As education administrators around the country gear-up to implement this policy in 2013, you may well hear more about this issue.

In doing so, it is worth reflecting on the teacher you recall as your favourite teacher; the one about whom you reminisce and say “what a great teacher”.  Was it because she or he drove you to a singular focus on academic performance or was it because of a personal connection that inspired you? 

After all, it was Albert Einstein who noted:  “Not everything that can be counted counts, and not everything that counts can be counted.”