Entries from CalculatorsAndComputers

Most of the animations are of constructions of some fairly obscure algebraic curves, but they are cool anyway.

This one, the "Pursuit Curve", I've never heard of, but from the animation you can see pretty clearly what a Pursuit curve is about. The red dot is 'pursuing' the black dot that is moving on the y-axis (the red dot will never actually touch the y-axis though).

Does anyone know the significance of this one, the "Logistic Map'?

And check out this ellipse one. This illustrates one of the characteristics of an ellipse -- that if you tie a string to the two foci, and trace a pencil around the inside of the string (keeping it taut), then the shape you'll draw will be an ellipse.

(hat tip, Bernie)

Jerry Mangus' textbook-less teaching has dazzled the U.S. Department of Education.

Mangus, who teaches fifth- and sixth-grade math at Plymouth Elementary, uses only computers to teach fractions and other numerical concepts to kids. He's built computer labs in his school, each of his students has his or her own machine, and their test scores have leaped.

For his efforts, the federal education department on Wednesday bestowed Mangus with its No Child Left Behind Act American Star of Teaching Award. The award, for which the department received some 2,000 applicants, goes to one teacher in every state and Washington, D.C.

"He's someone who has gone far and above," said Carolyn Snowbarger, director of the department's Teacher-to-Teacher Initiative, who presented the award.

Gone over and above? Even if this turns out to be the best thing ever, he's basically ceded his job to these web pages he sends his kids to. He's gotta be putting out less effort than ever before.

But this does make me wonder.

When Ben was about six, his spoken language was in trouble. He could speak, but there was often up to a 15-second lag between your asking him a question, and him responding. That's way too long for normal discourse.

We got him a copy of a computer game called Earobics, which is marketed as an aid for weak readers -- the idea being if a kid can link the written symbol with the sounds he is hearing, he can learn phonics and start reading better. In Ben's case it worked in a sort of inverted way. Very quickly after we began with Earobics, he began responding more rapidly in his spoken language, because the computer would prompt him for a response, and then something unhappy-making would happen if he didn't respond (for example, in one game, a balloon would pop -- he HATED the sound of popping balloons).

We decided that the computer was a good tool to use in this case, because no matter how we tried, we humans couldn't be consistent enough in dealing with his unresponsiveness. We'd give him a little more time, or another prompt, before giving up. The computer, conversely, was machinelike and unforgiving; the consequence came down 3 seconds after he'd been cued, invariably.

So, in that case, computers were just the right tool. Here's Mangus's explanation for why they've been successful for his students:

The key is the immediate feedback computers provide, Mangus said. Kids don't waste time doing homework wrong, and then feel the frustration of bombing out when they get the answers the next day, Mangus said.

Of course, I check Ben's math homework every night, so he gets almost-instant feedback. But I can see where he might prefer instant feedback from a computer, rather than me. And gee, even I might prefer that...

But I still believe you've got to get a kid to do math with his hand. Maybe not all the time, but some of the time. And there are also conceptual problems that you run into when you try to get a calculator or computer to do the work of a teacher (check out this post for an example).

So, if this guy is doing something right -- and there's so many questions left open here, such as: how is he assured that the kids are covering all the topics they are supposed to get in the grade they're in? -- then how is he getting around the downside of using computers in the classroom?

Taxpayer-supported school computer and Internet giveaways are political gold, but studies have questioned whether they actually help student achievement. This research, presented at the American Educational Research Association's annual meeting, confirms skeptics' doubts. In one study, researchers from Syracuse and Michigan State universities examined a program that gave laptop computers to middle-school students in Ohio in 2003. Preliminary findings are mixed.

"Overall, we don't know if it is a worthwhile investment," says Syracuse researcher Jing Lei.

About 37% of the children say they stare at the screens for more than three hours a day; a few report more than five hours a day. Parents help kids with homework more often and students' grades benefit slightly, but teachers report more classroom distractions as students check e-mail. And students actually feel distracted: In the first year, their grade-point averages rose modestly, but when Lei and a colleague asked them to estimate their GPAs, students actually believed they dropped.

"They felt that time is not used as effectively as before," she says.

Laptop giveaways are the latest educational fad; five states either have or will soon have them. More than one in eight school districts have some sort of program in which every child gets a PC.

Evidence has shown that computers are finding their way even into the homes and schools of the nation's poorest students. A Tennessee study found that schools serving low-income children had more computers than your typical school — 125 for poor kids' schools vs. 114 elsewhere, and computers in low-income schools often were more connected to the Internet. But using computers, for instance, to teach reading in primary grades actually showed negative results.

source:
Computers may not boost student achievement