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14 April 2019

Careful the things you say...

Careful the things you say… Children will listen.  

       - Sondheim, Into the Woods

Teachers are generally savvy enough to avoid saying crazy-stupid things, at least in front of students.  I’m expecting that anyone reading this blog doesn’t need to be told to steer clear of off-color jokes or denigrating comments about students.  Duh.

But even good, experienced teachers often don’t recognize the power of their words when expressing personal opinions.

In one of my early years teaching, a conversation with students touched on which sports we enjoyed.  I spoke as I would have with friends, expressing love for a few sports, and particular disdain for another.  You who read my blog know that of course I respect the students who dedicate their time to playing that sport; I was merely offering a personal preference, as one does when conversing with friends.  Thing is, those students didn’t know me as well as friends or colleagues.  In their minds they heard a respected adult say “This sport you love is bad, and I think less of you for devoting your time and energy to it.”  (Certainly that’s NOT what I said; that’s the gist of what the students took away, though.)  Thus without intending to I became a less respected adult.  It took several years and occasional enthusiastic attendance at games for my relationship with players to improve.

I write now to offer particular caution about wading into discussion about “screen time” and cell phone usage.  Our faculty has fractured into factions:  The usual suspects gleefully posted links to a recent Atlantic article arguing that cell phones are “destroying the teenage generation."  Next, we were referred to a scholarly point-by-point takedown of the Atlantic’s evidence and reasoning: “That’s why it’s time for us to stop paying attention to alarmist attacks on kids’ screen time - and instead pay attention to our kids.”

While I have my own opinion on this controversy, one that most readers can easily intuit, I do respect that there are intellectually legitimate arguments on both sides.  Nevertheless.  I recommend that we all put discussions about the moral merits of technology into the same category of off-color jokes - don’t engage.  Why not?  The same reason we shouldn’t express disdain for an activity that a student loves, whatever our personal thoughts.

Consider the effect on teenagers who overhear incessant faculty or parental conversations about screen time.  They don’t necessarily internalize the logic of the debates; they hear adults, adults who have power over them, denigrating something they love very much.  Even if you are taking the side that generally aligns with students’ own views, merely having the discussion in front of them rubs students’ noses in the fact of their impotence.

In your (non-physics) conversations with students, it’s worth considering that, whatever the truth of the matter, students feel as if they are a powerless, disrespected underclass.  Tread very carefully.  Your relationship with students can so easily be damaged by words which students interpret as contempt for things they love, as disrespecting their autonomy, as you allying yourself with The Man (or, just as often but less idiomatic, The Woman) who is keeping them down.

12 April 2019

Mail Time: coverage vs. pace in AP Physics 1. It's not a binary choice.

On a physics mailing list, a teacher asked about the "battle between comprehension and coverage" in AP Physics 1.  That's a great question, one that I'm asked a lot.  My response is below...

Firstly, the class structure you indicated - essentially first-year physics students meeting for a bit less than 315 minutes per week - is more than sufficient for AP Physics 1.  For comparison, I'm teaching first-time physics students on a 225-minute week starting in late September with copious breaks.  You're in good shape time- and structure- wise.  :-)

My own advice to teachers is to work at YOUR pace, designed to get a reasonably deep treatment of fundamental concepts before April 1.  That means moving on, even when some students seem like they don't get something.  Why?

(1) The ones still struggling with material likely won't improve their understanding right now with simply more instruction.
(2) The ones who *do* get the current topic will become bored and less cooperative if you don't move along.
(3) The ones who seem stumped now will likely appreciate a new topic that might be more comprehensible.
(4) The ones who seem stumped now will almost universally make a comment later in the year like "oh, remember when we thought this was hard?"  :-)
(5) The quicker you get to putting all physics topics together in a creative way, the happier and more successful your students will be.

Physics is best learned in small, unrelated chunks over a long time period.  Some people call this "spiraling".  Let your class see the same topics in different contexts, and eventually most students will get most topics just fine.  Different contexts means not only integrating topics with one another, but also using different approaches to understanding physics: quantitative, semi-quantitative, descriptive, experimental, etc.

I don't think the choice between coverage and pace is as stark as you make it.  If you're teaching e.g. kinematics well but quickly, and revisiting kinematics in brief chunks throughout the year, then you don't need to "cover" e.g. rotational kinematics later on - you can simply explain what a radian per second means, and let students to problems and experiments for a day.  They'll get it without additional work.  And once students are familiar with a disciplined approach to learning physics and solving physics problems from your work early on, then later specialty topics (e.g. Coulomb's law) can be doled out for students to figure out on their own.  They will, and quickly, too.  :-)

The last month before the AP exam provides the venue for students to put the whole course together, to teach each other, to figure out that the topics that were so difficult early on are straightforward now that they understand how to learn physics in general.  It's beautiful to watch each year as the class gets more relaxed and more comfortable with what they know, and as they learn to focus on what they CAN do rather than what they can't do.  After all, they only need ~55% of the available points to get a 4 on the exam!

Here's a link to an article from written back in 2008, addressing pacing issues in AP Physics B... the point is, Less is More.  The advice is still good regarding the new course, which doesn't require anywhere near the same crazy pace.  

Good luck!


01 April 2019

Jacobs Physics Podcast: S2 E4, about the experimental bouncing ball problem on the AP1 exam

Today's podcast goes deep on the experimental problem from the 2016 exam.  Digressions include:

* How many readers we needed to grade this problem
* Why and how this problem promotes creative lab work in your class
* NOT giving your students a lab sheet
* The difference between a "plausible plan" and a "detailed procedure"
* How to write, and to teach students to write, a lab procedure for the AP exam

Here's the link.  As always, feedback is welcome.  Email me or post a comment, and I'll address it in the next episode.

Tech pointer: someone mentioned having difficulty downloading a previous episode. These are all shared via google drive.  They seem to work fine for me on either an iphone, an ipad, or a computer.  (I haven't tested on a non-apple mobile device.)  I did once have my phone say "file not found"; but if I told it to "open link in new window", everything worked fine.  It worked so fine that it wouldn't shut up when I opened my music app, and I had to pause the podcast manually.  :-)