Embracing chaos in the physics lab

I run week-long AP physics summer institutes, which are essentially classes on how to teach AP Physics 1.  In terms of expectations and attitudes, these institutes turn into a microcosm of my full-year classes for high school students.

My students - and the APSI participants - have been conditioned to believe that the spectrum of good and evil is contiguous with the spectrum of lawful to chaotic.  Problem is, learning is not linear; learning does not obey neat rules.  Many of my best students would not be labeled “lawful” in a role-playing game - they’d be neutral, or very often chaotic.

I totally understand that, in an elementary classroom, chaos simply must be tamed into order so as to avoid the Hobbesian State of Nature that would otherwise be, well, natural.  If it's done right, elementary education should be far more about establishing how to relate to one another in civil society as about serious academic content.  Just as with the rules of writing or musical composition, rules of school must be learned and internalized before they can be professionally broken.

But physics students are emphatically not in elementary school any more.  They know well the rules of appropriate class behaviour and relationships.  While it is certainly important for teachers to intentionally build a positive class culture, we absolutely do not need to use elementary school style rules.  

Nor do we need any "rules" at all.  

When an authority figure dictates to a teenager an externally-imposed rule, the teenager rebels.  Sometimes that rebellion is external, with derisive body language, passive-aggressive or even actually-aggressive speaking out.  Probably more often the rebellion is internal.  A teenager may have learned to present submissive body language and to control their tongue.  Yet, teenagers sneer in their heads, they make plans to break or test each rule, they convince themselves the rule doesn't apply to them, they know from experience that they won't actually be held accountable to the rule.*

*Just as often the teenagers simply didn't register the rule at all because they were thinking about sex when the rule was presented.

***

At my summer institutes, I begin by talking to the group from the front of the room using powerpoint slides.  Why?  Because that's what participants expect.  They'd be confused, uncertain, and in most cases angry if I began the week by saying "pick your favorite AP problem and set it up experimentally right here with no guidance or instruction from me, the guy you're paying to give guidance and instruction."

By the middle of the first day of an institute, I've moved on to quantitative demonstrations - still me talking from the front of the room, but using physical equipment to verify the predictions I make on the white board.

Then by day's end, I've stopped talking at the board altogether.  Everyone does a motion graph activity, in which they individually communicate their predictions about the motion represented by a graph.  They bring their predictions and justifications to the front of the room, where I either help them communicate their prediction better... or I check off their prediction, at which point they go to the back of the room to use a motion detector and cart to reproduce their assigned graph.

During this last activity, I don't move - I sit at a desk, talking to each participant in turn as they come to me in a line.  In front of me unfurls a scene that would make my second-grade teacher's head explode.  Participants talk to each other, they physically walk from one classmate to the next seeking suggestions, they drop equipment, they set up equipment in both right and wrong ways... and all the time, I sit there, making not even an attempt to control the chaos.

It's not about control.  It's about lawful chaos.

See, I don't believe in Hobbes*.  Left to their natural state, students certainly are chaotic, but they are not usually selfish.

* Using synecdoche here about Leviathan - not referencing Hobbes the Comic Tiger, whose existence and philosophy I wholeheartedly support.

I don't give the institute participants - nor my students - a list of rules, guidelines, or instructions for this activity*.  Nevertheless, goodness rules.  People help each other, both with the predictions and the experiments.  They discover naturally who has the same graphs to work on, and so "lab groups" form organically.

* The one "rule" that applies here and throughout everything my classes do is the "Five Foot Rule" - students may collaborate freely, but they must separate themselves by five feet before writing anything to be turned in.

In my classes that run in this manner, it's quite rare that I have to call out a student for being "off task."  My tolerance for chaos must be high, of course - I can't be a control freak.  Yes, it often happens that I hear students talking about the upcoming football game; yes, I can occasionally see a student check a text message.  I've got to hold my tongue.  I only say something when the conversation becomes more than a short break - and then I am extraordinarily careful to be polite and respectful.  "Hey, Mr. Jones, I'm coming to your game today, let's talk about it there, okay?"  I don't take a phone away unless students truly can't control themselves - and then I'm still as respectful as I can be.  (The one time years back when I got outwardly frustrated with a student on a cell phone, I severely damaged the relationship with him and at least one of his friends.  My frustration was justified - yet my reaction hurt the situation, it didn't help.)

How do students know what is appropriate or inappropriate if I don't go over rules and guidelines?  They know because they are human beings with 14-19 years of experience interacting with other human beings.

Look, I recognize that's a flippant answer.  If you're asking this question - which I know many readers are - it's not because you're incompetent or stupid.  It's because you're legitimately worried.  Probably you're worried in particular about that one student who thrives on negative attention from their peers and teachers.  What if they don't even pretend to do physics, but instead go from classmate to classmate causing distractions, deliberately sowing the seeds of churlish negativity?  And then, how do you defend yourself to an administrator when you ask the student to leave, but (s)he says with false sincerity, "I didn't know what to do! I didn't know it wasn't okay to talk about non-physics things, and teacher didn't give us any rules or guidelines!"?

That's a battle that many of us, unfortunately, will have to fight.  But rules won't help.

If your administrator is giving any credence whatsoever to such a disingenuous complaint, then this administrator isn't going to suddenly come down on your side if you can show them how the student violated subsection (b) of class rule 3.2i.

Find a way to deal with the one underminer.  Don't seek justice, seek peace - that is, you don't need disciplinary consequences for a pain-in-the-butt student, you just need to be able to separate them from the class when they're not engaging.

This way, the rest of the class won't be afraid to relax and have fun.  Fun is chaotic... and that's okay.

I'm teaching a fall 2019 online course in physics/physics pedagogy

Hey, all... this is an ad, but an ad for something you or someone you know may be interested in.

I'll be teaching an online physics course on circuits through the Putnam-Westchester Industry & Science Teacher Alliance (PWISTA).  Check out the Science Teacher Mastery Program.  Each class in the program is equivalent to what would be a two-to-three week content unit in a first year college physics course, but aimed at students who are * physics teachers.

* or intend to become

Do you know someone who is familiar with physics, but needs guidance in physics pedagogy, needs to know how to help her or his students understand physics?  Or, do you know someone who is being asked to teach physics, but is primarily a biologist or chemist and thus needs some content support?  Either way, this course will be of use.

I'm offering just one class this fall: Circuits.

For each, you will get access to all of my topical course material, both when I teach at the high-school (Conceptual or Regents) level, and when I teach at the college (AP) level.  This includes the labs, problem sets, and quizzes that I assign.  I'll give you written guidance about how to use this material in your teaching, and for your own study.

Then, I will host five one-hour online sessions on Thursday nights this fall (see schedule below).  In each session, I'll spend the first half discussing practical pedagogy, just as I do in my workshops and on this blog.  In the second half, I'll discuss specific content, problem solving, and test preparation issues as requested - or, I'll improvise where the participants take me.

See, I'm more than happy to address individual needs.  For each class, I will be videoconferencing via google hangouts from my lab.  This means I can show live experiments.  And, as people have questions that stray beyond the circuits demos I had set up, we can improvise to talk about anything of interest to the folks who sign up.  Yes, we're going to learn about circuits... but I'm happy to discuss whatever is on your mind with regard to your physics classes.

Participants can get 15-hour CTLE certificates and/or university credit hours through Purchase College.  They can also get three graduate credits in science education through Manhattanville College - see the site for details about credits, certificates, and pricing.

You can see the full course description via this link.

If you have further questions, please contact me via email or twitter; or, contact Mark Langella, head of PWISTA, through their site.  Mark teaches the chemistry courses, and has been a College Board consultant for many years - he's the varsity, in case you know anyone who wants a similar program in chemistry.

Schedule for PWISTA Physics fall 2019:

The following are Thursday night classes.  I'll meet each night from 8:00-9:00.

Sep. 26
Oct. 10
Oct. 24
Nov. 7
Dec. 5
(Dec. 12 available as an alternative.)

Product review: Vernier's Go Direct motion detector (and PASCO's similar product)

Way back in 2010, when I didn't even own a smartphone, I began to explore the use of phone/tablet apps for classroom use.  I wrote, 

I have little doubt that, five years down the line, Pasco and/or Vernier will have updated their data collection line such that the probes work wirelessly with the iPad or equivalent, and the LabPro or LabQuest will be unnecessary.  

They say, either predict the event OR predict the date - never both.  Then you'll always be right.  Within five years, Pasco had indeed made it possible (though not at all easy or cheap) to use their sparkvue app to view the output of their probes.  A couple of years ago the PASCO Smartcart revolutionized motion and force detection in the high school lab.  (I bought a bunch of these.  They're great.)

And finally, as of this summer, I'm seeing all the probes I regularly use available from Vernier and Pasco in a bluetooth version.  I've bought a bunch from Vernier; I've tried out both the PASCO and Vernier versions.  Today I'll focus on just one...

The Vernier Go Direct Sonic Motion Detector

My wife and sidekick, Burrito Girl, can't stand wires.  They look messy, they get tangled... she was amazingly thrilled eight years ago when I bought her a bluetooth keyboard for her computer.  She would love this motion detector.  If she cared about physics equipment, that is.  

It's extraordinarily compact, just a Borg Cube 2.5" on a side.  No wires.  One side - the business end - includes the power button and the sonic generator.  Two of the other faces have a threaded hole for a mounting screw.  And one face includes the microUSB for charging*

* or for connecting to a LabQuest, if you want to.  You don't have to.

There's no demand for a dedicated interface - no LabQuest, LabPro, ULI*, etc.  It sends its data via bluetooth to the smartphone or tablet.  And the app couldn't be simpler.  The "Graphical Analysis 4" app is free to download.  You open the app to connect the motion detector.  That takes three clicks.  The fourth click is to collect data.  That's it.  Even a 9th grader could figure it out without instruction - good thing, since I'm teaching 9th grade.  

* Now I'm really showing my age.  I used the Vernier ULI in my classroom back when Things Were Otherwise and the Moon was Different.  I even used the motion detector connected to an Apple IIgs when I was a student.  When I visited Vernier in Beaverton a few years ago, they showed me Dave Vernier's special space where he kept, in working order, every version of Vernier probes and interfaces they've ever made.  I nerded out a bit, showing the same enthusiasm as when my bachelor party walked through the Corridor of Star Trek Artifacts at the Las Vegas Hilton.  Is that Worf's actual bat'leth?  Is that the interface that used a serial port to connect to a PC?

By default, the detector collects for five seconds.  Here's a screenshot of a typical velocity-time collection.  (Switching to position or acceleration is a matter of just two obvious clicks!)  Of course, as is typical with a sonic detector, it missed a point early on - no cart in my classroom was actually moving 18 m/s, i.e. 40 mph or so.  The real motion was captured after about 1.5 s.

I have to teach students to recognize the physical unreasonability of this common graph; then, I have to show them how to zoom in such that they get the output that makes sense.  On a labquest, zooming requires highlighting the relevant part of the graph, followed by two not so obvious clicks.  Oh, and it requires that the touch screen actually works, which is about as likely as an American Airlines flight departing on time.*

* The similarity is striking - just like with AA, the labquest is somewhat likely to have minor maintenance issues, which are not complicated to solve, but no mechanics are available right this instant, so it'll probably have to wait until late tonight.  In the morning, either the labquest/airplane will be working fine, or a replacement will be trundled in.  Fat lot of good that does anyone right now, of course.

But on the app, highlighting and zooming is a breeze.  I use my finger on the phone touchscreen that always works; I hit the magnifying glass button; and voila, the relevant graph shows up - see the screenshot.  The app is so, so intuitive.  Click a point - the vertical axis value shows up.  That's all I care about for basic data collection.

Yes, the app can do far more.  The button in the bottom-left of the screenshot brings up an easy to navigate menu of further analysis options, including slopes and integrals and curve fits and interpolation - it even lets you add your own annotations.  This app contains very powerful tools, tools that can be used for my undergraduate-level research projects.  I rarely need its most powerful tools, though, so I'm glad that the app has simple and useful default settings.  

Now, PASCO makes a very similar product - a compact, bluetooth sonic motion detector.  It works well, too.  I prefer Vernier here not because PASCO is bad, but because the Graphical Analysis app is far more intuitive to me than the Sparkvue app.  You might have a different opinion.  Try them both.  

The good news is, the landscape of PASCO vs. Vernier has changed.  For decades, teachers have had to choose one sensor manufacturer or the other.  The $250 or so per lab station for a Labquest or Capstone interface, plus $100 per probe that only worked with its own interface, meant that the Vernier-Pasco choice was for richer, poorer, sickness and health, till death do us part or the warranty expires.  

No longer!  With the advent of the smartphone-as-interface, now we are able to pick and choose among the bluetooth probes and devices.  For example... PASCO beat Vernier to the punch by about a year with their wireless smartcart.  I bought a classroom set of these.  But now I'm buying Vernier motion detectors, photogates, and force probes - with no sunk costs.  The smartcarts still work great with the free sparkvue app.

The moral is, just buy whatever of these bluetooth probes you like, from whichever manufacturer.  You're not constrained by your past purchases; you're not locking in to your lab's future.