For each question, I first put the question up on the screen, then activated the short answer response. Students submitted answers (anonymously), and as a group we went through them on the screen, removing duplicate answers and those that clearly did not address the question. I gave them a few minutes to discuss the remaining answers, and then I hit the vote button, and students voted for which they thought was the best answer. We then further discussed and clarified, so that everyone was on the same page.

For my second period class, this worked really well. They had fun, they were engaged, and they left feeling smarter. We had, after all, spent eighty minutes addressing their questions, and they asked if we could do the activity again. I was pleased as punch that it had worked out so well, and even more pleased that the kids left feeling pumped about learning.

Until my fourth period class.

In Fourth period, the kids behaved entirely different. They were distracted, they wrote silly answers to the questions, they voted for the silly answers, and basically blew off the entire activity. It was immensely frustrating, particularly for the few who actually wanted to learn.

It was a useful reminder that not only are individual students unique, individual classes have their own unique dynamic as well. And that just because an activity works brilliantly with one class, doesn’t mean it will with another.

These equations, at face value, are straightforward – in other words they can plug in the numbers and get an answer. But there I something subtly insidious about them – they are just confusing enough that students are unable to apply these formula correctly later. Why? Because they are overly scripted, making the calculations look more complicated than they are, implying that without the formulas, they would not be able to achieve the “correct” answer. They build a reliance on formula, rather than concepts – and formulas without knowing what they mean can lead to trouble – much like poor Mickey’s spell in The Sorcerer’s Apprentice.*

So after an abysmal assessment (which was in part a setup – I could see they were becoming formula dependent), I gave them the following question:

Both images represent the view through the same microscope, with exactly the same settings. How big is the object in the second image?

Their first question? “Which formula do we use?”

My response was a shrug.

I watched as they struggled – one or two figured it out pretty quickly, but others tried dividing the object width (~12mm) by 7 (and some by 8!), some multiplied by 7, some divided by 40 (the circle diameter), but it was clear they were searching for a magic formula. Some, after scowling for a good long time, finally asked “which units do we use? Millimeters or UM’s?” (Aaaagh! That’s not a U! That’s a µ!)

It was challenging to subtly hint at how to simply measure the object without “giving” them the answer, because I didn’t want them to revert to the mindset of me, the teacher, as the sole gatekeeper of knowledge. Eventually they worked it out. Some estimated, some marked off the length of the object on a pencil or sheet of paper and held it to the millimeter scale, and the cleverer ones borrowed a friend’s sheet and held them together in front of a light. (And those that just used someone else’s numbers, well, I had multiple versions of the sheet, so they invariably had to redo it anyway!)

The next question was a bit more involved. I said the view in the image above was through a microscope with 10x ocular and 2x objective. I then asked what the FOV would be using a 20x objective. Despite my earlier warning stay clear of equations for this exercise, I saw many pulling out the equations from the previous lab. And that’s where they really got into trouble…

Numbers were thrown willy-nilly into the equations in the hope that somehow they were correct. Several students, despite correctly identifying the magnifications as 20x and 200x, wrote out

40 / 200 = 7mm / x

When I asked where the 40 came from, they said “low power on a microscope is 40x”.

“All microscopes?” I asked. That threw them.

Eventually I helped them work out that the higher magnification was ten times the lower magnification, so the view would be zoomed in ten times as close. The FOV should then be 10x as small (which is in itself a tricky concept, students are tempted to say 10 times the magnification means bigger, so the FOV is 10 times bigger). For most it eventually clicked that 10x the magnification means the field diameter is 10x smaller. Simple and no formulas to memorize.

It was remarkable, in a way, that a simple set of four of these questions took them a full 80 minute period – but that was mainly because I wouldn’t let them get away with wrong answers. One could call it a waste of a period, but I would not. It was absolutely necessary.

This is exactly the kind of thing Eric Mazur talks about. I will definitely be doing more of these exercises in the future!

*I mean the Fantasia version. Though that scene is included in the recent Nicholas Cage film.

How many of you remember this from the movie Wayne’s World:

OK… First I’ll access the secret military spy satelite that is in geosynchronous orbit over the midwest. Then I’ll ID the limo by the vanity plate “MR. BIGGG” and get his approximate position. Then I’ll reposition the transmission dish on the remote truck to 17.32 degrees east, hit WESTAR 4 over the Atlantic, bounce the signal back into the aerosphere up to COMSAT 6, beam it back to SATCOM 2 transmitter number 137 and down on the dish on the back of Mr. Big’s limo… It’s almost too easy.

That was funny in 1992. But it is now two decades later, and what was amusing for its implausibility then has become the norm now. For example, I don’t have a thermometer at my house. Instead, I have a computer in my pocket (masquerading as a phone) that uses satellite data to locate itself, then accesses the internet wirelessly to look up the temperature (and weather for the next few days) in my location, all displayed on a high resolution hand-held screen. Why? Because it is easier than buying a thermometer!

Yes there are political and financial concerns (and, hey, there were none of those in the renaissance, right?). But the rate of technology is advancing so fast, we casually perform tasks that would have seemed magic a scant decade ago.

I, for one, am very happy to be living in this century.

This pay-off is terrific. The kids are pumped that they actually received replies, and they are also pumped that the replies did not fully address their concerns (I think some are preparing a response!). So even though we are at the end of the next unit, they are re-energized.

I love it when a plan comes together!

1. With my Grade 9’s, since we are working on the Chemistry unit, we did a Great Periodic Table of the Elements Bingo Scavenger Hunt! And yes, the exclamation mark is part of the title. The class is divided into teams of three or four, and each team is given a large periodic table and a bingo marker. The rules are:

1. Each team will collect items (or photos of items-see #6 below) that contain a particular element. Note that the element must be prominent or significant in the item, not merely “traces of” or contamination.
2. Each item will be confirmed by the teacher as containing that element, which can then be marked on the periodic table.
3. After one hour, the team that has collected the most elements wins.
4. Even if an item contains multiple elements, that item can only be used for one. In other words, one item (or multiple identical items) cannot be used for multiple elements. In addition, items that are physically collected cannot be shared between groups.
5. When collecting items, you must have permission for each item.
6. If an item cannot be moved, or you do not have permission to collect it, you may instead take a photograph, but one of the team members must be in the picture.
7. You must be quiet and respectful in the hallways. If you make noise or are disrupting in any way, you may be removed from the game.
8. Only those items (or images) returned to the classroom within the allotted time are counted.
9. Good luck!

It took up a full 80 minute class, the kids had fun, and they even learned a thing or two. During the final class, my colleague and I did a few chemistry demos – stoplight reaction, zinc and sulphur combustion, Marge’s Hair (natural gas bubbled through bubble solution), and an alcohol pulse jet. End with a bang!

2. With my Grade 10’s, they are working on something a bit more involved: stop motion animations of mitosis. Some are doing old-school flip-book style, some are doing a rapid sequence of powerpoint slides, and some are doing flash. One used pasta. Awesome.

3. With my 11 Biology class, we did a timeline of evolution. I came across this tutorial  for creating an interactive timeline using scripts and a Google Docs back end. It takes a little bit of prep work, and you have to be familiar enough with RSS feeds and HTML to get it working, but it is quite effective once the bugs are ironed out. Each student was given a person on whom to produce a brief bio (background people mostly – Buffon, Cuvier, Lamarck, Linneaus, Smith, Malthus etc.), which they submitted using a Google Docs form, and it then automagically showed up on the timeline. Because the timeline page uses third party scripts hosted elsewhere, they can have a copy of the HTML file on their local machine which shows the live data.

Merry Christmas, joyous solstice, happy Hanukkah, or whatever you celebrate have a peaceful holiday, and a happy New Year!

*they justify this by saying “we don’t do anything in the last week”, and of course we can’t do anything in the last week, because half the kids are gone.

But I hate when concepts are simplified to the point of an outright falsehood, especially when it is so obvious that the kids recognize the lie. Take the model of the atom as taught in Grade 9 Science, for example. We are told that as we move out from the atom, the “shells” are able to hold more electrons, and then we are told that the first three shells hold 2, 8, and 8 electrons. Every year I get the same two questions immediately: “If shells farther our hold more electrons, why do those two have the same number?” and “How many does the 4th shell hold?”

So this year, I told them flat out before going into the model that I was going to lie to them. I told them that the information was simplified to the point of being factually incorrect. Then I told them that the shells hold 2, 8, and 8, and that the third shell is the lie. This did a remarkable job of focussing their attention, as now they wanted to know how this “lie” model differed from the “truth” model. So I explained that the third shell actually held 18 electrons (answering question 1), but that the shell had two volumes – volume 1 and volume 2. Volume 1 held 8, and volume 2 held the other 10, but that the electrons in the second volume behave like electrons in the 4th shell, and that it gets complicated. I let them know that if they wanted to learn more about the hows and whys of electron shells, I would be happy to discuss it outside of class time, but since Grade 9 Chem unit only deals with the first 20 atoms, we would stick to the simplified 2, 8, 8 model.

A few stuck around to learn more, but many were relieved that they didn’t have to learn the more complicated model just yet. And I didn’t have to lie to my students. Everyone wins.