Wednesday, July 13, 2011

An apology for posting inaccurate information

I've probably posted this (inaccurate) chart a dozen times, and regret doing so. 
It shows public education spending going through the roof, while test scores remain flat. 

The cost of public education has indeed increased as shown. 
My mistake was in assuming that the miserable flatlined test scores were accurate.
Here's why I was wrong:

In the Atlanta Public School system, the administration held "cheating parties", in which they met at a teacher's home to change test scores. 

A similar thing happened in Pontiac, Michigan. 

Here's more on the Atlanta mess:
Teachers and principals erased and corrected mistakes on students’ answer sheets.

Area superintendents silenced whistle-blowers and rewarded subordinates who met academic goals by any means possible.
Superintendent Beverly Hall and her top aides ignored, buried, destroyed or altered complaints about misconduct, claimed ignorance of wrongdoing and accused naysayers of failing to believe in poor children’s ability to learn.

....For teachers, a culture of fear ensured the deception would continue.

“APS is run like the mob,” one teacher told investigators, saying she cheated because she feared retaliation if she didn’t.
The voluminous report names 178 educators, including 38 principals, as participants in cheating. More than 80 confessed. The investigators said they confirmed cheating in 44 of 56 schools they examined.
So.   I humbly repent of publishing that chart so many times.
The chart is inaccurate. 
Test scores have not remained flat despite the spending increases.  If Michigan and Georgia are any indication of what's going on in government schools, test scores have declined. 

My bad. 

Go here to read an outraged editorial about the pro-choice movement that wants to privatize the public schools and give students and parents some other options. 


Hot Sam said...

In Freakonomics I believe they uncovered cheating through statistical analysis. They found that the percentage of correct answers on the last questions were significantly higher than the early part of the test. This suggess that students didn't finish the test and teachers filled in the correct answers for the unanswered questions.

The problem with your chart is the choice of scale. The test scores are compressed in a low, narrow band. If they were on a wider scale, it would be easier to see the variations and trends. It might still be relatively flat but it's hard to tell.

the other problem is the expected link between pay and scores. The scoring system is not linear - a single point in the higher end of the distribution distinguishes you more from your peers than a point in the middle of the distribution. For example, in Olympic swimming, the Gold and Silver are separated by hundredths of a second. Bronze and no medal are separated by about half a second.

these are also averages, so an increase in the mean of only one point might be a great achievement. The test has an absolute maximum and absolute minimum, so the effects of outliers are diminished. The distribution also has diminishing tails, so moving the average is most likey the result of improving the majority of students.

The appropriateness of the pay increase, if based solely on test scores, depends on the marginal impact. Since teachers have many students, a small improvement for many kids is a big boost to total productivity.

but I agree with yor gut instincts. Pay increases are probably more related to aggressive collective bargaining and pandering politicians, not educational outcomes. The unions would say that there was a need for teacher pay to "catch up" with "comparable" private sector salaries. There is some truth to that - teacher pay lagged far behind other public and private salaries in decades past. But then they caught up.

On the other hand, when you consider the alternative career choices of teachers, their opportunity cost is very low. If they weren't teaching, they'd probably be making a kick ass cafe latte somewhere.

Many teachers pad their pay with advanced degrees that confer no additional teaching skill.

I went to both Catholic and public schools, and I thought our public school was pretty darned good. But I took a lot of honors and AP classes. Even the worst public schools turn out excellent students. Educational outputs are more dependent on parental involvement than teaching quality.

still, we have a lot of teachers who are morons, and the union puts the interests of the teachers ahead of the students. Administrators are cut from teacher cloth.

I sat next to a high school freshman on a recent flight. He was very smart and respectful. He said "yes sir" and "no sir" to everything I said. His parents were doctors and he was going to follow in their footsteps. However this young man came to be the person he is, teachers had little to do with it. If anything, he made their jobs easier, more pleasant, and rewarding. He brought up the average test score for them. He deserves to be paid. But he will be - in the private sector.

The Whited Sepulchre said...

Yep. It was in Freakonomics. That's one of the books that got me going on this site.

Like a roulette player who always bets on black, no matter what, I always, always, always push for giving people a choice.

(And I always, always, always assume that any official govt. stats have been fudged.)