Peer Teaching

Ms. R. helps a peer with her experiment.
Ms. R. helps a peer with her experiment.

Half the Chemistry class was gone yesterday, so they had to make up their experiment today. Well, one student of the students who did her work yesterday entreated me to lead her peers through the experiment. It was pretty awesome, because she had been struggling with the topic for the last week and had finally gotten it yesterday.

And she did an excellent job. She not only walked the rest of the class through the theoretical calculations, but guided them through the experiment itself.

Peer teaching works best when students are excited about what they’ve learned and want to share. I’m still trying to figure out the best way of inciting this excitement when I break the groups up for their projects. Giving them choice is important, but also, I think, giving them challenging work that they’re proud to accomplish.

Snow Days

The road to school (from the west) on a snow day.
The road to school (from the west) on a snow day.

With all the cold temperatures and serial snowstorms, it has been quite the winter in Missouri. The wonderfully hilly roads around St. Albans are picturesque, but can become quite tricky with a fresh layer of snow and ice. Our head of school is understandably cautious, so we’re on our forth snow day this semester even though we’re only one month in.

Kids sledding (at home) on a snow day.
Kids sledding (at home) on a snow day.

Abstract = Spoilers

Although it feels like you're giving away the whole story -- because you are -- the Abstract should be all spoilers.
Although it feels like you’re giving away the whole story — because you are — the Abstract should be all spoilers.

I was trying to explain that the abstract of a lab report was a really brief summary of everything in the report.

One of my students said, “Oh, so it’s like spoilers.”

And they were right.

If you didn’t know, spoilers are little bits of information that give away the plot. While you don’t want any spoilers if you have not seen the movie, in a lab report you what to give away the plot because since it’s a short, concise summary, it’s what most people will read.

So now my middle-schoolers are submitting lab reports with a section called “Spoilers” on the cover page.

Turning off the Lights: How we Behave in the Darkness

Darkness can conceal identity and encourage moral transgressions.

— Zhong et al., 2010: Good Lamps Are the Best Police: Darkness Increases Dishonesty and Self-Interested Behavior in Psychological Science.

My students asked me today if we could turn off the lights during biology class and just use the natural light from outside. I’m usually not opposed, but it was overcast, so it would have been a little dark.

I put it to a vote and we had just one or two students who were against it. My policy in these cases, where we’re changing the working environment, is to respect the wishes of the minority unless there’s a compelling argument about why we should change things.

One student proposed a compelling argument. At least he proposed to try to find a compelling argument.

“If I can find a study that says lower light is better for learning can we do it?” he asked, with his hands hovering over his iPad.

“Sure,” I replied, “But not today. You can do it on your own time.”

We’ll see what he comes up with tomorrow. I, however, ran into this article that describes a study (Zhong et al., 2010) that found that, “participants in a dimly-lit room cheated more often than those in a lighter one,” (Konnikova, 2013).

While both groups performed equally well on a set of math problems, students in the darker room self-reported that they correctly solved, on average, four more problems than the other group—earning $1.85 more as a result, since they were being paid for each correct answer. The authors suggested that the darkness created an “illusory anonymity”: even though you aren’t actually more anonymous in the dark than in the light, you feel as though you are, making you more likely to engage in behaviors you otherwise wouldn’t.

–Konnikova, 2013: Inside the Cheater’s Mind in The New Yorker.

Konnikova’s New Yorker article is worth the read, because it summarizes other factors that encourage cheating as well as things to prevent it. Things that encourage cheating:

  • a messy environment,
  • if your peers all do it,
  • when the people you’re stealing from seem to have a lot,
  • when you’re thinking that your behavior is set in your genes and your environemnt (and you have less free will),
  • when you’re in (or even think you’re in) a position of power,
  • when you have achievement goals (think test scores), as opposed to mastery goals,
  • when you’re tired, or sleep-deprived.

The things that discourage cheating are the things the encourage some self-reflection, like:

  • the feeling of being watched (even just the presence of mirrors or pictures of eyes,
  • writing down an honor code,
  • being asked to think about your previous immoral behavior.
  • having a strong moral compass (some people are just much less likely to cheat than others.

And finally, it’s important to note that we will tend to rationalize our cheating, so we’re more likely to do it later.

So, I think it’ll take a lot of convincing to get me to turn off the lights, except perhaps on very sunny days.

Embeddable DNA

Ravenclaw’s four genes on the DNA string annotated. Note that start and stop codons bracket each gene, and there is non-coding (junk) DNA between each gene.

Using English words like “blue eyes” to represent genes in DNA strings with the DNA Writer runs the risk that students start to wonder if actual genes are coded in English.

I’d say it was a small risk, but today I did have that question from a couple of students today.

Fortunately, it was quite easy to disabuse them of the impression: they didn’t actually believe it, but they just had to know for sure.

I did like one of the questions though, “Does that mean that Spanish people have DNA written in Spanish?”

Embedding the Tiles

With that caveat, since I, and a few of my students, like the pretty patterns the DNA Writer produces (see above), I created a way to embed the color sequences into other webpages like this blog.

By default, the embedded image links back to the DNA Writer website, but you can adjust it so that it does not. Instead, the nucleobase tiles will change color when you click on them. The color changing helps keep track of where you are if you’re trying to string the sequence in beads.

For academic purposes, you can also change the message you get when the mouse hovers over the tiles. By default it give the plain English translation, but you can make it say whatever you want, or even have it just show the base sequence.

Some People Just want to put Chemicals on Stuff to See it Burn

“We want to put chemicals on it and see what happens,” she said.

I was not quite sure how to respond. First of all, I didn’t know what “it” was. Secondly, I had no idea about what chemicals the three of them wanted to “put on it”. And thirdly, I was wondering why they even thought that students could just wander into the chemistry lab and get my permission to “put chemicals” on some random stuff, just to see what would happen.

For the last question, alas, I’m afraid to say that they may, perhaps, know me too well. However, given my visceral antipathy to inexact language — especially in a science lab where safety is always a concern — based on the first two questions, they don’t know me quite well enough.

An interrogation ensued.

“It” turned out to be two sad-looking pieces of dried apple. They weren’t dried when they’d been left in someone’s locker who knows how long ago, but they were pretty dessicated now.

The “chemicals”, on the other hand, they weren’t quite so sure about. Or at least they didn’t want to tell me right away. They may have had different ideas about what they wanted to see.

“We want to see it burn and smoke!” explained the second one happily. I didn’t have to express either skepticism or approbation verbally, my face responded automatically.

“We just want to see bubbles and stuff,” suggested the first one somewhat tentatively; eying my facial expression carefully.

The third one said nothing, but she tends to reticence. I looked at her inquiringly to give me a second to think.

That’s when I realized that they were all in chemistry together. They’ve been working with chemicals, studying different types of reactions for the last eight months, so they probably had at least some idea about what they were asking about.

The Montessori axiom is to follow the child, and here they were expressing an interest in chemistry. It was an ill-formed interest perhaps, but an interest non-the-less, so maybe there was something I could work with.

I needed a way to gauge just how serious they were about their project, and, at the same time, tie it back to what they’d been learning in class. Were they interested enough to puts some serious thought into it?

So I told them that, if they could tell me exactly what chemicals they wanted to use, and write the chemical equations to show what would happen, I’d let them do it.

They were on it.

The first thing was to figure out what was in the apples that could react. Well, the apples had come pre-sliced, and fresh in one of those small, clear, plastic bags. The first student, who was taking charge of the group, ducked out of the room to retrieve it from the garbage can across the hall.

I’d expected that the ingredient list to be very sparse. Ideally just the single word, “apples”, with maybe the type of apple listed if the packet labelers were feeling verbose. However, it turns out that those “fresh” slices needed something to keep them looking good and tasty. So these fresh apple slices appear to contain some amount of calcium carbonate. That was a chemical they knew.

Their first thought was a single replacement reaction. If they added potassium to it then the potassium would replace the calcium and they’d see something interesting. It took a few minutes, and a little nudging of the quiet one to help out with the charges, but eventually they wrote out and balanced the reaction:

2 K + CaCO3 –> K2CO3 + Ca

The problem is, I pointed out, there’s nothing in that reaction that would produce bubbles. I didn’t even want to bring up heat and the exothermic and endothermic reactions, nor the fact that potassium is a solid, as is the calcium carbonate, which would make getting them to react dramatically a little bit difficult. I didn’t even point out what would happen if the potassium came in contact with water (or even sodium), because I know Ms. Wilson is planning on doing that little demonstration in the near future.

So what reactions produce bubbles? This took some further thought. With a few dropped hints, they came up with acid-base reactions, particularly, the reaction between calcium carbonate and hydrochloric acid. I pretty much told them what the products would be, and, with a little more coaxing of the quiet one for help, they were able to balance the reaction.

CaCO3 + 2HCl–> CaCl2 + CO2 + H2O

Now they were finally good to go. Unfortunately, it was also time to go P.E.. And they’d managed to drop one of the apple pieces into a bucket of water that my calculus students had left lying around after their bottle draining experiment.

So I told them they could try it tomorrow. Unfortunately, tomorrow is the field trip, so they’ll have to do it the day after.

We’ll see how it goes.