Thursday, March 22, 2007

Science Project: Rocketry

Fran and Ammon stopped by for a few days and we had a great time launching Ammon's new rocket a few times. If you're like me, you're wondering "How fast does a model rocket go, anyway?"

Take a look at it in action:



This is from about 25 yards away. We don't get to see the whole flight, but we get enough of it to estimate its terminal velocity. Using a program out of Kenyon College, I tracked its motion frame-by-frame.

I calibrated the distances in the video with the height of my brother-in-law. Ammon is ~68 inches tall, which makes him about 13 pixels tall at 25 yards.

The green "plusses" in the frame on the right are the data points I used to figure out the terminal velocity of the rocket:

A couple of conclusions from this:
1. That max speed is 38 meters per second, or about 90 miles an hour!
2. Think I'm just too white and nerdy.

Sunday, March 11, 2007

Book Report: Punished by Rewards


I haven't written a book report in a long time, but I've been reading a lot lately, and sometimes it's hard to process and internalize a good book without doing something with it. So indulge me and if you actually read the book, let me know what you think!

Why we do what we do is complicated. How we get people to do what we want them to do is a lot less complicated. People with kids know that one way to get what you want out of them: reward them for good behavior and punish them for bad. But does this approach actually work? Alfie Kohn challenges this conventional wisdom about motivation at home, in school, and in the workplace in his 1993 book “Punished by Rewards”.

In dealing with my kids, I’ve thought about punishment and spanking in particular, and I’ve never personally been able to justify physical violence disguised as teaching. Rewards, on the other hand, are just the opposite, right? Instead of focusing on bad behavior, rewards put the emphasis on good behavior and encourage it with incentives. But Kohn points out that ultimately punishments and rewards are not opposites because they are both used to manipulate behavior artificially. This idea has sort of an ominous “Brave New World” feel to it, that the way to make people “good” is to manipulate them into doing what you want. The problem with this is that when I’m not around to manipulate anymore, then who’s going to keep them in line. Really, at the end of the day I don’t want my kids doing things or not doing things because something artificial will happen to them, good or bad.

Even more important, using rewards starts looking at things kids want not in terms of how much they enjoy them, but how they can be exploited as rewards. And I don’t want to make things that my kids are entitled to (like my love and attention, for example) to be dangled in front of their faces and made conditional “rewards” for good behavior. Ultimately, I want them to be good people because it’s the right thing to do, and because they’ll be happy.

But what really put me over the edge with rewards is that there is dramatic evidence, and lots of it, that using external (extrinsic, they call them) motivators has a lot of negative side effects, such as killing creativity and genuine interest. In one example, young writers who spent 5 minutes thinking about the kind of rewards they were promised for their work produced less creative work than students not encouraged to think about these things. In another study, 51 preschoolers were given magic markers to draw pictures. Some were told that if they drew pictures they would get a special certificate decorated with a red ribbon and a gold star. After a week or two, those given the incentive were less interested than the other kids. What’s more, these observations aren’t limited to kids. College students and workers in the workplace are subject to similar effects when controlled by external rewards, including grades and financial incentives.

There are a few things that rubbed me the wrong way about the book, like lumping “positive reinforcement” style parents in with totalitarian punisher-parents. I'm still convinced that using rewards to influence behavior is a lot better than beating your kids into submission (a sad situation for everyone involved), even though both only give you temporary obedience. And his unrelenting disapproval of rewards and punishment made me sure that this guy has never potty-trained a 3-year-old or seen a kid smack another kid for no obvious reason. This made me skeptical of any advice he had about parenting small children. But my measure of a good book isn’t how much I agree with it, but how much it makes me think. Clearly there are times that rewards and punishments are appropriate, but the in-your-face artificial consequences world we have a tendency to create puts emphasis on administering "consequences" (good or bad) and less on learning to make good choices. This book made me think a lot about how we motivate people (or create conditions that foster authentic motivation), and how we motivate ourselves.

Saturday, March 03, 2007

Brandon on Manhood


Brandon asked me today if I'd cut his hair. He says it's getting long like Kelsie's. I can understand that. He's a boy and he shouldn't have girl hair. But Brandon corrected me:

"I'm not a BOY!" he said.

"Oh? What are you then..." (please don't say a little girl...)

"I'm a MAN!" he bragged.

"You're a man?"

"Yeah! I'm a man!" he confirmed, so pleased that I was starting to understand.

"When did you become a man?" I asked, truly interested.

"When we had the baby, then I'm a man."

There you have it. Having a baby makes a man out of you...and your son.

And so Brandon and I had our first man-to-man talk.

Things that go "bump" in the night.

I came across a video this past week describing how to make a little toy called a "bump key." It's supposed to be a super lock pick that opens any lock that it fits into. I'm pretty skeptical about these kind of things, so I had to try it out. I mean, if this is for real, then I'm going to have to do more than remember to lock the doors at night.

After making 3 of these, I finally got one to work. I think it's time to install some chain locks...