Tuesday, 29 April 2008

stop teaching about science - UPDATE

A month ago, I wrote that we need to stop teaching about science and start having students do science. What started me down that path was the observation that trouble with science seems to start with math, and trouble with math seems to start with abstraction. The solution, then, would seem to be: stop doing all this abstract math. Make math more concrete, and it'll be more relevant and easier to apply. Right?

Not so much.

A new study shows that far from easily grasping mathematical concepts, students who are fed a diet of real-world problems fail to apply their knowledge to new situations. Instead, and against all expectations, they were much more likely to transfer their skills if they were taught with abstract rules and symbols.

The use of concrete, real-world examples is a deeply ingrained part of the maths classroom. Its advantages have never really been tested properly, for they appear to be straightforward. Maths is difficult because it is a largely abstract field and is both difficult to learn and to apply in new situations. The solution seems obvious: present students with many familiar examples that illustrate the concepts in question and they can make connections between their existing knowledge and the more difficult concepts they are trying to pick up.

The train problem is a classic example. Another is the teaching of probability with rolls of a die, or by asking people to pick red marbles from a bag containing both blue and red ones. The idea is that, armed with these examples, students will recognise similar problems and apply what they have learned. It's a technique deeply rooted in common sense, which is probably as good an indicator as any that it might be totally wrong.
Chad is quoting from the NYT here, and he follows it up with some nice examples from his own experience as a physics prof. The basic problem is mental compartmentalization. "Many students seem unable or unwilling to take things learned in a class in one department and apply them to subjects studied in a class in another department."

What I think this indicates is that teaching is complicated. At some point in my MA year, I came to a realization that shocked me at a fundamental level: I had never and would never receive any formal training in the subject of, well, teaching. All of my training is on the subject: history and philosophy of science.

Somehow, the more specialized the subject matter you mean to teach, the less you're expected to learn about teaching. My friends who are preparing to teach grade school have spent years studying and putting into practice various pedagogical theories. A buddy who teaches high school chemistry effectively has degrees in both teaching and chemistry. A five-minute conversation with any one of them often makes me completely rethink my lesson plan.

Time for the meta: if I apply my suggestion about science to teaching, here's what I get: we should stop teaching students about teaching, and instead start having them do it. Turns out, that's precisely what I'm doing. Oops.

Turns out, it makes as little sense to expect students to automatically pick up abstraction from concrete examples as it does to expect them to pick up skills from facts. There's more than one kind of knowledge. The real trouble seems to be that we only test one kind at once.

Monday, 28 April 2008

how to shoot yourself in the foot -- UPDATE

As expected, the government ordered the TTC back to work yesterday, and today everything is fine and dandy, except that no one really gets why the union went on strike in the first place. To clarify matters, here's what was going on:

Sunday, 27 April 2008

april 27 roundup


  • "In essence, no one really knows today what a kilogram is." [via LA Times]
  • son-of-a-bitch mouse solves maze, ruins chances of scientific discovery. [via the Onion]
  • "Two things make tall buildings possible: the steel frame and the safety elevator. The elevator, underrated and overlooked, is to the city what paper is to reading and gunpowder is to war. Without the elevator, there would be no verticality, no density, and, without these, none of the urban advantages of energy efficiency, economic productivity, and cultural ferment." [via New Yorker (long, but worth it)]
  • "I’m afraid I have some bad news for you: You walk wrong." [NY Magazine (very long, worth skimming)]
  • Oh, Internet, how I love thee:

Saturday, 26 April 2008

molecular gastronomy


Hat tip Torontoist:

Start with the caviar and hazelnut foam. Next, try the bacon-stuffed tangerine segment appetizer, and follow with a palate-cleansing sorbet of kiwi and heirloom tomato purée. You'd be a fool to miss the rock lobster meatloaf, which is served atop an oasis of fig and cucumber gelée. Finish with a candied beet root custard and a tassé of chipotle-scented espresso. Bon Appétit!

Haute cuisine fans will descend on Isabel Bader Theatre (93 Charles Street West) this Tuesday, April 29 at 7:00 p.m. to meet Hervé This, the renowned chemist who is credited with coining the term molecular gastronomy and discovering the perfect temperature for cooking an egg (around 65°C). This will be signing copies of his book, Kitchen Mysteries, and giving a lecture on meat glue, liquid nitrogen baths, and other innovations in food science.

More posts about food.

... and furthermore

While I'm on the subject of how unions can be annoying, I should mention that I'm a member of a union, too. It represents the teaching assistants at the U of T, and it does a pretty good job of it, at by anecdotal comparison to a few of the US institutions where I have friends. But I do have one big beef with CUPE, and it's that the leadership seem to think international affairs are their business. Social justice is important, but it just isn't appropriate for my local union to make pronouncements about Israel's attitude toward Palestinians. Especially since some of CUPEs membership are Israeli. It puts us all in a bad position. I want my union to devote its energies toward protecting my high pay and keeping up with rising tuition. I care about the plight of Palestinians (and the plight of Israelis generally), but CUPE is just the wrong venue for that discussion.

Social justice is a hard thing to say no to these days, because when you say no you look like a big meanie (or a Republican!). Devotees take disagreements personally, and it can be dangerous to express a dissenting opinion in academia (it's not as bad as David Horowitz makes it out to be, but liberals can be just as petty as conservatives).

Easily Distracted has some good things to say about the sort of no answer that should always be valid:
No, this is the wrong institution or place for us to be doing that.
No, you (or I or we) are the wrong people to be doing that.
No, I know more than you do about what those ideas mean, so don’t try to tell me what to do. You should be listening to me instead.
No, this is an elitist institution that is just appropriating the language of social change for its own ends.
No. Is there a keg anywhere at this meeting?
There are more. Go read them.

how to shoot yourself in the foot

Last week, there was talk of a TTC strike. The city's mayor threatened to declare public transit an essential service (like firefighters and police) so that they couldn't strike. So the TTC agreed to give 48-hours notice before walking out. Last Friday, they gave their notice, leaving everyone (well, me anyway) worried over the weekend. Fortunately, at the eleventh hour the city reached a deal with the TTC Union bargaining team, and the strike was averted. All that was left was for the union membership to ratify the agreement, which included upgraded medical coverage and a 6% raise over the next two years.

Last night, at 10pm, the membership voted by a 2/3 margin to reject the agreement, releaseing a statement at 11 that as of midnight, public transit was on strike. Small piece of advice to transit workers: don't strike without warning on a Friday night. For better or worse, drunken revelers have a lot to say about public opinion, and stranding them to grab a cab ride home just isn't going to help your case.

Though the discussions are not public, and no statements have been made as to the basis for the strike. Rumor has it that the grievance involves the outsourcing of TTC maintenance work, which if true is a valid enough worry. But why destroy whatever public support they had by stranding riders?
More:
• commentary from transit advocate Steve Munro
• Globe and Mail blog coverage
• Toronto Star coverage
• National Post coverage
• Toronto Sun coverage
• Torontoist coverage
• Blog TO coverage
I've kept my strongest views about the TTC to myself, mostly because I am not used to being in a place so heavily unionized, and these views are decidedly anti-union. Whether officially designated as an essential service or not, the TTC is certainly essential to me, though rising costs are making year-round cycling a more and more attractive alternative. Subway trains each have at least two employees on board during operations--a driver and a watcher (she's the one who sticks her head out a window to make sure no one has their foot stuck in the gap before the train leaves a station). I'd eliminate them both, in favor of computerized trains. I'd also change the cash-ticket-token-daypass-weeklypass-monthlypass system to a single card system, where riders could buy single fares, lots of fares at discounted rates, or term-limited unlimited passage. They could purchase cards or add fares to cards at any subway stop (at automated machines that would take cash, debit, or credit), and they could also add fares online. The new card system would involve adding card swipes to buses and streetcars and would allow for the elimination of some of the ticket counter personnel. Also, there would be no advertising anywhere on the TTC. Not on the sides of buses, not in subway stations, and not in subway cars. That's my TTC.

Friday, 25 April 2008

how to choose

B: Well, I had coffee with Alyssa, and we really hit it off — she’s beautiful, and charming, and laughed at my jokes. I definitely think we would get along well over the next few years. I met Cindy, too; she’s a knockout, and clearly very talented, but there wasn’t as much of a spark there.

A: That can happen. So are you going to choose Alyssa?

B: I’m tempted, but the thing is — Cindy’s US News ranking is much higher.

A: Her what?

Sean's talking grad school choice, here, people.