## Wednesday, March 11, 2009

### Not Everyone Can Be in the Top Quartile

Dina wrote a very engaging dialog explaining how she might go about calculating her "teacher percentile", and why it is impossible with the data available.

And I realized what was the most bothersome thing about Bill Gates' recent bloviating about teacher quality. (Not, by a long shot, the only bothersome thing.)

He made this particularly asinine and ill-informed observation:

A top quartile teacher will increase the performance of their class -- based on test scores -- by over 10 percent in a single year. What does that mean? That means that if the entire U.S., for two years, had top quartile teachers, the entire difference between us and Asia would go away. Within four years we would be blowing everyone in the world away. So, it's simple. All you need are those top quartile teachers.

So simple!

Aside from all the other reasons it's not simple, Bill, your math is wrong.

You don't understand what a quartile is.

Take a group of people and measure something numerical about them. Their height, let's say. Take those heights and make a list of them from greatest to least. Cut that list into four equal sized chunks. The top chunk is the top quartile.

Surely everyone with half a brain notices the problem with his statement. We can't replace all the teachers with top quartile teachers. You only have a top quartile when you compare and rank the entire group. Only 25% of teachers can EVER be "top quartile". (Not to mention, say you buy this line of crap and go ahead and fire 75% of the teaching force. Where, exactly, is this magical pool of top teachers to replace them?)

You have to wonder what would happen if Bill got his wish. If 75% of working teachers were replaced with all these awesome, amaaaaazing teachers who are currently for some mysteeeerious reason not teaching. Do you think that after the first year he would realize that only 25% of the new group of teachers were top quartile? I picture him at his big Surface(tm) desk, pulling his hair, rubbing his temples, lamenting "How is this POSSIBLE?"

I thought he was supposed to be so smart...he should come sit in my 9th grade algebra class in a few weeks. That's when our Stats unit is. I will enjoy the moment when the kids realize they know more than Bill Gates.

Calculus Dave said...

Classic. I love it. Reminds me of this comic:

http://anotherrandomday.com/?id=521

Matt said...

Just to play Bill Gates' Advocate for a moment... he might not have meant the top quartile of all teachers currently teaching. He might have meant the top quartile of all people who COULD be teaching. (Or, heck, the top quartile of all citizens.) Or, I dunno, something along those lines.

Kate said...

OK, Matt, maybe he meant something other than what he said. But that is not what he said. He said:

"A top quartile teacher will increase the performance of their class"

and

"if the entire U.S., for two years, had top quartile teachers"

His statements indicate that he believes that every working teacher can be "top quartile".

unapologetic said...

This just goes to show that Seattle in the late 1960s didn't have top-quartile math teachers.

RichSkyline said...

First we hear he won't let his wife or children have iPods or iPhones, now THIS!?!?!

JYB said...

I think what Bill Gates meant was that if all teachers could be as good (in the future) as the teachers who are in the top quartile (in the present).....

Either way, the assness of what he says has more to do with his love affair with conservative education practices. This is someone who dropped out of college. He clearly didn't see the value then yet his big idea of change is doing more of the exact same things people have always been doing.

Clix said...

I'm with JYB on this, but for me, the point is, it's important to make sure that what you say = what you mean!

Kate said...

OK of course I suspect he meant something more like what JYB is saying. But the irony that he's using words, in his public speech about the quality of education, and being sloppy about their precise meaning, shouldn't be lost.

I don't see educational leaders giving speeches about improving search algorithms. Maybe Bill Gates should consider the folly of holding forth with his opinions about improving education. With words from statistics that he does not bother to use correctly.

Kevin said...

Sure you can replace all teachers with top-quartile teachers---just fire 3/4 of them and have the remaining ones work 4 times as hard. (Hey, that seems to be Arnold's solution in California!)

Kathryn J said...

I found this blog by following a link from "The Line". Truly awesome and now subscribed to in my reader.

The misconceptions involved in recent pronouncements on education should keep math teachers busy for the next century.

Ken Rodoff said...

I know where the 75% needed are:

They are downtown, most of them, somewhere high-above street level, working for law-firms, accounting firms, firm-firms.

And some are consulting (roughly 6%).

The best know better. The 'best' know that the emotional currency that carries many a teacher pales in comparison to the pecuniary benefits garnered from making a better living.

In the meantime, this quartile-d teacher needs to get back to teaching.

The kids are looking at me.

At least a 'quartile' of them.

Nice blog. Good stuff. You owe Dina a fruit basket. Maybe a croissant. I think she's a picky eater.

Kate said...

Welcome everyone from The Line. I'm glad we are attacking Bill on two fronts. English and Math unite! :-)

David Cox said...

Choose a time when your class is acting pretty high and mighty and hit 'em with "ah, half of you are below average anyway." See how long it takes for them to figure it out.

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