Thursday, May 8, 2014

Jeff Johnson's Teacher Task Force sites flawed studies on teacher quality

Jeff Johnson's Teacher Task Force sites flawed studies on teacher quality.

For example, on page 17 of the report, it cites from an American study on Teacher Quality:
Replacing a (bottom 5 per cent) teacher with an average teacher would increase the present value of students’ lifetime income by more than $250,000 for the average classroom in our sample.
Bruce Baker of Rutgers demolishes this study here.

Baker writes:
One of the big quotes in the New York Times article is that “Replacing a poor teacher with an average one would raise a single classroom’s lifetime earnings by about $266,000, the economists estimate.” This comes straight from the research paper. BUT… let’s break that down. It’s a whole classroom of kids. Let’s say… for rounding purposes, 26.6 kids if this is a large urban district like NYC. Let’s say we’re talking about earnings careers from age 25 to 65 or about 40 years. So, 266,000/26.6 = 10,000 lifetime additional earnings per individual. Hmmm… no longer catchy headline stuff. Now, per year? 10,000/40 = 250. Yep, about $250 per year (In constant, 2010 [I believe] dollars which does mean it’s a higher total over time, as the value of the dollar declines when adjusted for inflation). And that is about what the NYT Graph shows.
What this boils down to is that a student can get a lifetime boost of $5 a week if we now spend billions of dollars on value-added rating systems. Maybe. Or maybe not. 
So what's my point?

Laura Servage summarizes my point well:
Few would argue that there is a link between teacher effectiveness and student learning, and few would disagree that this link is of central importance. Measuring the link is another matter entirely – a matter so complex as to warrant reams – and I mean reams – of academic research focusing on the challenges of such measurement.
Jeff Johnson and his Task Force need to stop citing flawed American studies and borrowing America's Education Reforms that have been nothing short of a raging failure.

No comments:

Post a Comment