Friday, March 31, 2006

Now Entering Free Association Zone

Bulleted lists. Almost as good as sentence fragments.
  • I hate it when I'm in the men's room washing my hands and practicing making faces in the mirror when someone walks in, because then I have to be all serious, like "Gosh, what's that in my eye?", and plus I have to try not to crack up.
  • When I start counting how many papers are left in the stack to grade, I know it's time to take a break. Eventually, I will split it up into a sequence of piles of 5, and play games with myself about grading the next five before I stop again. Eventually I have trouble getting through a stack of five. Doing almost anything is better than actually grading.
  • I'm traveling this weekend and making a somewhat long trip for essentially business purposes. (It's about as long as the trip to Atlanta--yeesh.) But I'll end up within 20 miles of a good friend from college, so I'll get something nice out of it as a bonus by getting to visit her. 
So I'll talk more when I get back. Have a good weekend!

Tales from the Snack Machine

I put a dollar into a snack machine in the classroom building today for an 80 cent snack. It beeped and spit my dollar back out, telling me I had to use exact change. I was bummed, but it occurred to me that maybe the machine was out of dimes and nickels, but might still have a quarter left. So I put in a dollar and a nickel and tried again. Success! And in change, the machine gave me... three nickels and a dime. Probably including the nickel I just put in. Someone is not programming these things carefully.

A friend told me that last year there was an even weirder programming glitch on a different campus snack machine. Items which were marked 80 cents and on the bottom row could be had for 40 cents, but not if you put 40 cents into the machine. You had to put in at least 80 cents (he usually used a dollar), or the machine would know you hadn't put enough money in. But if you put in at least 80 cents, you'd get the snack plus all but 40 cents of your money back.

And plus, one time I heard from a friend whose hairdresser's college roommate's brother knew someone who was driving down a road, when a snack machine started following them down the road flashing its high beams into the car, and then she called 911 on her cellphone, but the police said she was calling from inside the snack machine, so she stopped by a state trooper who anatomically incorrect, and there was a peanut butter cup hanging from the side view mirror. Plus the snack machine was smashed into the grill of the car.

Now one of the three tales above is made up. Can you guess which one?

Thursday, March 30, 2006

Random Updates

Using bulleted lists is a great way to avoid having to write coherent segues:

  • My cat (the aggressively nice brown and black one) is still hanging around. He seems to come sneaking out of the bushes every morning when I come out on the porch. The white one is still hanging around some too, and they seem to get along well. I think she's his girlfriend now. I hope at least one of them is spayed/neutered.
  • I picked up a Tai Chi DVD a few weeks ago and have made what are probably some hilarious attempts at learning something. I do tend to get tickled 'though since all the moves seem to have names, and they come at you sort of rapid-fire. "Now we will do 'Parting the Wild Horse's Mane'... now 'Moving Hands Like Clouds'... now 'The White Crane Spreads its Wings' ... now do 'Inserting the Broomstick into the Donkey's Butt'." (The last one is just to see if you were still paying attention. Actually, I misheard "Moving Hands Like Clouds" the first time and thought it was "Moving Hands Like Clowns"; it gives you a totally different impression of the movement, doesn't it?)
  • One of my colleague's tells me that a major problem on the last assignment he graded was students saying that "33 = 9". I told him it probably resulted from someone asking the smart German exchange student "Is 33 = 33?", to which he responded, "Nein."

Wednesday, March 29, 2006

Monday, March 27, 2006

The (Nearly) Unteachable

"Unteachable" here refers to the material, not to the students. (Not that I've never had a student who gave me the thought.)

Some things are hard to teach. Like good geometric visualization, or essentially, geometric intuition. How do you sketch a solid described in terms of algebraic curves and surfaces? How do you visualize the intersection of several surfaces in three dimensions? More importantly, how do you teach someone to do this?

In one class, I have to teach students to find volumes of solids of revolution. Years ago I found out these students have trouble making a sketch of a solid of revolution. Not because they lack prerequisite math skills (well, OK, sometimes because of that too), but because they lack the prerequisite drawing skills, and the essential geometric intuition that goes with them.

How do you draw a cylinder? Well, here's one way:
I know the top is a circle, so I'll draw that. I know the sides are straight, so I draw that. And the bottom is flat, so I draw that. And here's the cylinder:

We can call that "art primitive", also sometimes known as Picasso. So maybe my students are primed to make way more money than I do, since this is how many of them draw three dimensional objects. (Actually I long ago resigned myself to the fact that my students will make way more than I do right out of college.) But if you're willing to accept the developments of the Renaissance, you can draw in perspective:

I know that the top and bottom are disks, BUT, because I'm looking across the disks, they will show up foreshortened, looking more like ellipses:

And now you have a drawing in perspective. (Note that I make no claims as to being an artistic master. In fact, in college I took a drawing class in which I think the professor would have been more interested in the first drawing than the second. Overall, I prefer the second, which belongs to a school of art a friend dubbed "Drawing Things That Look Like Things." While it may be frowned upon by professional artists, "Drawing Things That Look Like Things" is much more useful if you are trying to solve a problem involving geometric figures. Perspective is a good thing.)

I remember in grade school, we used to occassionally watch a guy on TV who gave half-hour drawing lessons. I don't remember his name, but he taught how to draw things "in perspective" by foreshortening, and also how to apply shading to make an object look more three dimensional, and other things like that. He was pretty thorough in each example about explaining (and showing) us just exactly what to do, and so my drawings usually turned out pretty decent by the end of the show.

I think part of the difficulty my students have is that they never got this kind of instruction in grade school, so ideas about how to sketch a three-dimensional object are kind of foreign. (Perhaps another unfortunate side effect of eliminating subjects like art from the curriculum so as to spend more time learning to take bubble-in tests?) But that makes it harder for them to see three dimensional objects, too. I realized years ago that part of what they needed were basic drawing lessons, and so I often give some quick and dirty practical tips for drawing the figures. As a result, the pictures come out a little better, and I hope this helps them visualize the regions they're working with.

I give them some other tips, and of course practice helps too, so I tend to encourage them to try lots of examples and draw lots of pictures. But ultimately, I'm not teaching a technique or an algorithm, I'm trying to teach them how to see how three dimensional objects interact in space. And that's really tough.

Thursday, March 23, 2006

Students act out jokes for my amusement

So one day, three of my students are waiting to enter heaven. St. Peter says, "We're running behind schedule, so we can only take one of you today. I will take whoever can explain to me what is the meaning of Easter."

The first student says, "That's easy! Easter marks the beginning of Spring Break!"

St. Peter shakes his head sadly, and says "No, I'm afraid that won't do at all."

So the second student makes an attempt: "Easter weekend is the time when there are fabulous white sales."

St. Peter says sadly that this too is incorrect, and looks dubiously at the third student, who says:

"Easter is the Christian holiday that coincides with the Jewish celebration of Passover. Jesus was crucified and he was buried in a nearby cave which was sealed off by a large boulder." St. Peter is surprised and delighted, and is about to gesture the speaker into heaven, when the student continues: "Every year the boulder is moved aside so that Jesus can come out, and if he sees his shadow, there will be six more weeks of winter."
Ok, so my students were not the original subject of the joke, but I think there is a deep strain of truth in this. I don't know how often I'm nodding along like St. Peter, delighted at a student response which shows they understand, they really understand, only to have the student tack on a final line about "six more weeks of winter" that tells me I've been duped again.

Maybe true wisdom is knowing when to quit talking and let people assume you know what you're doing.

Monday, March 20, 2006

Item No. 284 I do not understand about students

I share some large sections with another teacher. We use some online quizzes with multiple choice questions, mainly because I'm not quite insane enough to attempt to grade very many stacks of 160 of almost anything, and neither is she. On the other hand, on some assignments (like labs) we include one free-response question which we grade by hand. (Aren't we devoted teachers?)

On the last quiz, the free-response involved a lot of notation, including some equations with fractions and exponential functions, which are hard to type but easy to write. We explained that for this reason, rather than have them attempt to type an answer into the online quiz, we would have them write their answer by hand and turn it in. (Aren't we nice teachers?) We took these up in class the week before break, and I finished grading them over break.

Of course, as is the case every year, somewhere around 5-10 percent of the written responses I get from my students are typed in Word (usually with painful attempts at typesetting) and then printed, rather than handwritten.

Friday, March 17, 2006

The Play's the Thing

I ran across an article on censorship (self and otherwise) of high school plays. (The highlight for me in the article is the school which dropped "The Crucible" (essentially about McCarthyism) and decided to produce "A Misummer Night's Dream" (about fairies and partner-swapping). Pure hilarity.)

It made me remember a trip I took in high school with our own theatre students. I wasn't in drama myself (yeah, I know, but I'm not always a stereotype), but the group was going to University Interscholastic League conference I was attending for a different reason, so I rode with them. The drama teacher and the students talked most of the way about different plays the students had been reading. Most of the conversation for about an hour trip out and an hour trip back followed a template like this:

Student: Have you read (*play*) by (*author*)?

Teacher: Yes--that's an amazing play. It... (*discussion follows*)

Student: Could we do that one?

Teacher: No, we wouldn't be able to do that here, it... (*insert reason for controversy*)

Lather, rinse, repeat...

It struck me as both sad and instructive at the time. Still does.

Monday, March 13, 2006

Cell Phones vs. Dementia

I'm not the first person who has noticed that someone having a conversation with an invisible person via a cell phone with an ear piece is not easily distinguishable from a schizophrenic. But at the grocery store tonight it suddenly occurred to me that the ubiquity* of such phones has provided great cover for those of us who tend to talk to ourselves a lot and occasionally realize we're doing it in public.

And after observing a woman working at a Chinese restaurant last night, I also have to add that the phenomenon is slightly more unnerving when the person is speaking a language that makes no sense to you.

*Except with me. I haven't yet found the cost/benefit ratio to reach a point where I'm willing to have a cell phone. That will wait until either I'm rich, or cell phones work better. Or preferably both.

Thursday, March 09, 2006

Cats I've almost had

I haven't actually owned a cat (my family did when I grew up), but cats seem to think I need one.

Years ago in my first apartment there was a little black cat that lived in the apartment behind me. One morning as I headed out the door, the cat headed in. Having grown up with another little black cat, my first instinct when I saw a cat heading for the door was to move my feet out of its way. Then I had the "Wait a minute..." moment after it ran inside.

From that point on it liked to come visit me from time to time. I usually didn't let it in (except when it was really cold out), but it would come by and say hello. It eventually moved away, and I think the owner went with it.

A few years later I heard a cat hollering out in the hallway on a cold night and found no one home where it lived, so of course I let it come in with me. It had a grand time sniffing and exploring everything in my apartment until I heard the lady next door come home. I went to let her know I had her cat. Now the cat of course heard her too; he knew she was home now, but he had no interest in leaving off a good explore, so I had to go retrieve him. Of course, as soon as we got to the door and he knew she could see him in there, he started wiggling mightily, I'm sure telling her "Help! Help! I didn't want to be in there! He made me! Save me!" Of course, she was a cat owner, so she didn't buy this for a minute.

I've been remembering some of these because I've had cats in my new neighborhood trying to invite themselves in. There's a big white one that's been hanging around for a while and who seems quite interested in coming inside, if I'd be agreeable. If not, I could just spend some time petting her while she rolls around on the ground, if I'd like.

I thought she might belong to the older lady who lived next door, since I saw her lounging in the front window once. Apparently she was just less cautious about her sneaking in than I was 'though, because the lady moved out almost a month ago and the cat is still hanging around. (She apparently belongs one more house over.)

More recently, I found this little black and brown one outside on a cold night, trying desperately to come inside.

I felt sorry for him but didn't want to let him in my apartment for the night, so I put a box lined with a bunch of towels out on the porch for him. (I peeked out the window later and saw him curled up in the box with his head poking up.) But not letting him inside was a real challenge. This has been the most aggressive cat I've ever found about trying to come inside. We spent some time with him trying to dodge around my hands and feet and make it inside. As a last ditch effort he poked his paw through the last crack of open door to keep me from closing it and then tried to wedge his nose through it. I kept telling him, "You don't live here," and I think he kept responding "I know. I don't care. It's cold out here."

Since then, he's proven to be just as aggressive, but incredibly sweet. If he sees me coming out, he'll come dashing up, collar jingling wildly, and try to get in my apartment. Once that's failed, he'll take all the petting I'll provide for as long as I'll sit with him. He gets very excited and starts poking his head under any hand of mine which is not currently in use. This morning when I finally stood up to leave, he stood up on his hind legs and grabbed my hand with his paws. "Hey, get back down here! I'm ever so cute!"

So far, I've avoided actually ending up with a cat, but I know I have the "Sucker" sign printed on my forehead (which animals in need can always read), so I assume it's just a matter of time.

Wednesday, March 01, 2006

Skewing the Statistics

I ran across a great article on what professors post on their doors in academia, and I think we may be an interesting outlier. (Seriously, the article is fun if you're in academia, or were there not long ago.) The author suggests that most posts break down into either humorous or items of serious pedagogical content. He does mention that there are plenty of other items posted:
...including provocative political commentary (protected by the venerable tradition of academic freedom), reproductions of famous works hanging in museums, finger paintings by professorial spawn, and other precious and smarmy visuals that Gasman and Epstein relegate to the lumpen category, "art."

Of course, I'm not sure about some of these distinctions. Are political commentary and reproductions of great art neither pedagogical nor humorous? My own bulletin board includes the articles on cell phone tracking and implanted human ID chips that I mentioned earlier, which I consider essentially educational; perhaps someone else would classify them as political. I also have this cartoon ("Let the kids decide") about creationist nonsense (many thanks to Oklahomans for Excellence in Science Education for having this up), which probably qualifies as humorous, educational, and political. But I digress.

Nothing anywhere in the article suggests that he ever ran across a door with the likes of Ooga Booga on it. Of course, if he did I'm sure he assumed it was in the kids finger-painting category and not thought much more about it. Our students tend to assume that. (Also, I have to grant that these are not on a particular persons door, but on the door to our common room we use for testing and which contains the fridge and printer. I'm not sure if that's better or not.)