Addressing AI use for school assignments - *It's not about AI!*

"I don't understand why using AI for assignments isn't allowed.  AI is a tool, right, like a phone or a computer?"  Peter made this comment in authentic good faith.  The tone was curious.  Peter, my student, wasn't being performative, or jockeying for social capital - no other students were even around.  He honestly wanted to know my thoughts.  And so I answered honestly and openly.

"I guess it depends on the purpose of the assignment," I told Peter.  "I agree, AI is a tool, a robot.  Would you use a robot to vacuum your floors?"

"Well, yes," he said.  "That's what a roomba is."

"Right," I said.  "Because the purpose of vacuuming floors is to have a clean floor."

I followed up.  "Would you use a robot to lift weights for you when the team goes to the weight room?"

"Of course not!  That's dumb," he said.

"Why is that dumb?"

"Because the purpose of weightlifting is to build muscles, not just to raise and lower a dumbbell."  Peter's eyes widened a bit.  "Oh, I get it.  That makes more sense now."

My analogy here is not likely novel or interesting to people reading this blog.  Conversations in which I explain simple ideas to teenagers are commonplace.  I mean, I teach 9th grade.  I'm used to student puzzlement about things that are obvious to me, things beyond Newton's third law.  For example, I had to explain the meaning of the word "sacred" the other day.  The student newspaper, edited by a senior, referenced "the Beatles rock musician John Lennon," which still provoked the question "what's a Beatle?"

So why do I relay my conversation about AI?  Well, because it's not only about AI.  AI is just the bogeyman of the day.*

*To paraphrase Neil DeGrasse Tyson, who was totally speaking tongue-in-cheek:  AI has been all around us for years.  It's only become a "problem" since humanities professors realized it could write students' papers for them.

The idea of a school assignment as authentic practice, in the same category as sports conditioning or musical scales, was foreign to Peter.  He had always thought of schoolwork as a chore, as a means to an end.  Get these answers right by any means necessary.  

Before you harumph at Peter, consider typical middle school or elementary school culture.  How often do you hear about parents who do their kids' homework for them?*  Even in 1983, a quick look around my class's "visual aids" would show twenty professional-level works of art, and two thrown together with watercolors and rubber bands.  Twice (in the 1990s) I took jobs tutoring middle school students.  Twice the parents stopped calling me when they realized that I wasn't just giving the student answers, and that I wasn't making myself available on short notice when said student forgot they had a major assignment due the next day.

*Well, the parents SAY "I never do my kids' homework for them!  But I always check it over to be sure their answers are correct.  If they're confused and I don't know how to help them, I ask my spouse.  Boy, do I hate it when a class covers material that we don't know about!"

Worse, my experience - in both public and Catholic school - was that teachers praised the students who produced high-end projects with, shall we say, heavy adult influence.  And the few of us with projects that looked like they were fully created by a middle schooler were either shamed or pitied.

I've often addressed assemblages of middle school parents who are considering sending their kid to my high school.  They ask, "what can we do to help our child be ready for the rigors of high school academics?"  My answer is always, "Make them do their homework on their own.  Don't help, check, read over, or discuss their assignments at all, ever.  Allow them to fail - and then let them recover.  Then they will know their successes are truly their own, not due to a 'support network.'"  

This response never fails to produce surprised looks.  Not hostile looks, as the parents are asking the question authentically and are willingly listening to the answer of an "expert".  It seems, from the reaction and the follow-up conversations, that most parents had simply never thought about the developmental purpose of authentic schoolwork.  

Just as Peter hadn't.

Joe Hicks, "in my judgment"

I attended the Harry Wendelstedt Professional Baseball Umpiring School in 2008, on school sabbatical.  For those readers who were not obsessed with national league baseball in the 1980s, Harry Wendelstedt was one of the best-known and most-respected* major league umpires during his 33 year career.  He was a very old man that year when I met him at the school.

*Respected, yes; but Wendelstedt wasn't God.  Doug Harvey was.

Toward the end of the five-week program, I asked some folks back home in central Virginia how I might get into umpiring at the high school level, now that I had serious training.  They told me to call local umpire supervisor Joe Hicks, a name I recognized.  I called.  I told the man on the phone with the Virginia down-home drawl that I was currently at the Wendelstedt school, and that I was interested in doing some umpiring when I returned.

"Oh, Harry!" Joe said.  "How's old Harry doing?  Tell him I said hi.  Oh, and we'll put you on our schedule this spring."  Okay.  That conversation went more easily, and more interestingly, than I anticipated.

Joe Hicks died last week, age 91.  At his funeral, no shortage of folks discussed Joe's friendliness, his kindness, his willingness to assume good faith of others and to offer help to those in need.  And yes, they discussed his baseball prowess.  They told of Joe helping his grandsons with their hitting when they asked.  They told how when Joe, age 70, was handed a bat during a game of stickball on the beach, his one swing ended the game - he hit a beach house that had been out of range for all others.  Joe was a small-town guy who became famous, yet remained humble, who never used his status for self-aggrandizement.  

I first met Joe and his umpiring partner Alex Smith in the early 2000s when I was coaching JV baseball.  They called virtually every game on campus, JV or varsity.  After the game, they would invariably head to our boarding school's dining hall for dinner.  I found out later that Joe deliberately assigned himself to Woodberry games because we were the only school who offered a free meal to go along with the $50 game check.  

I'd occasionally sit with Joe and Alex.  We'd talk baseball, and baseball umpiring.  Even before my foray to umpire school, I had a reputation on campus as a baseball rules expert; but here were two folks who were truly expert, and who were excited to teach me things.  Joe never let on about his history in the major leagues.  Alex let a couple things slip, bragging about how Joe had played for Casey Stengel, or how Joe had hit a walk-off home run off of Don Larson in the Polo Grounds.  Joe just said, "well, I did, but we didn't call it a 'walk-off' in those days."  

Joe welcomed me into the local association for the 2008 season.  He made sure I had a well-seasoned and supportive partner for my first-ever game.  After that game, Joe called me up to ask me how it went.  "Well, I didn't do anything crazy-bad, but I'm not happy with calling balls and strikes.  I know I missed two curve balls that dropped in for strikes."

"You only missed two pitches in the whole game?  I mean, that's great work!  You got hundreds right, then," he said.  Well done, Joe - being kind, building up the first-time umpire's confidence.  

What sticks with me about my umpiring conversations with Joe is how he taught me, and all umpires in the association, to handle conflict.  Again and again, an umpire would describe a tough situation they* had encountered; and Joe would recommend starting the explanation with a folksy, "coach, in my judgment..." 

* No, not necessarily "he".  Joe's association, in 2008, was the most diverse group of umpires I'd seen.  At umpire school, of 120 trainee umpires from all over the western hemisphere, 119 were white-looking folks, including one woman.  In Charlottesville, there were men of multiple colors, and many racially diverse women.  That's more usual in 2023, but Joe had reached across racial and gender lines before that was common in the hidebound world of umpires.

Joe's thesis was, the umpire is there for the express purpose of making judgments.  If the umpire sticks to that purpose, a coach has little room for argument.  An emphatic "I'm telling you, your runner was out" as a statement of fact practically demands the angry coach to riposte, "no he wasn't!"  But a calm "coach, in my judgment, the catcher put the tag on before the runner touched the plate" has a disarming quality.  Sure, the coach can give his version of events... but rather than emotionally charged statements of conflicting facts, the discussion becomes one of conflicting judgment.  And the umpire is the one paid to use their judgment to keep the game moving.  

I've used Joe's phrase - even his intonation! - "in my judgment," hundreds of time since 2008.  And only occasionally on the baseball field.  Usually, I'm discussing a student's placement (or lack of placement) in an advanced science course.  Or a failing student's plan to improve.  Or my observations of an interpersonal conflict on dorm.  Or a disciplinary matter at boarding school.  Or a problem I've graded.  "In my judgment, this response does not state that acceleration, not velocity, is to the left, and so does not earn the point."  I'm employed by my school precisely for my experience in putting forth this sort of physics judgment.  The 14 year old responding "well, in *my* judgment, it does" sounds silly.    

I miss you, Joe.  Rest in peace.

Center of mass calculations for AP Physics 1

The revisions to the AP Physics exams for 2025 are imminent.  I've posted about the formatting changes, which are truly no big deal for physics 1/2, and are so, so welcome in physics C.  (Doubling the time available for the exam, but not doubling the length of the exam, will allow students the time they need to approach complicated questions.)

The *content* changes are nonexistent in physics C. In P1, most folks are focused on the major change that adds fluid mechanics.  But what about the minor changes to P1?  They're there, too: the parallel axis theorem, quantitative questions about gravitational potential energy in orbits, and calculations with center of mass.

So what is there to know about center of mass quantitatively in AP Physics 1?

First of all, the conceptual treatment of center of mass motion that's already covered on this exam won't go away.  We still need to understand that the center of mass of a system obeys Newton's laws - with no unbalanced external force, the center of mass moves in a straight line at constant speed; with an unbalanced external force F, the acceleration of the center of mass is F/M where M is the system mass.

Then, the conceptual understanding of the location of a system's center of mass still is relevant.  For a symmetric object, the center of mass is in the, um, center.  For two equal-mass objects, the center of mass is right in between.  And for two unequal-mass objects, the center of mass is closer to the larger-mass object.

The new stuff is based on calculating the position of the center of mass using the equation m1x1 + m2x2 = Mtotal(xcm).  No, please don't write this equation using the notation from the updated official equation sheet, with summation notation!  Your students don't know what that ziggy-zaggy capital E is; and why is there an i in there?  We have to know about imaginary numbers now?!, they'll ask.*

*Yes, I'm aware that students must be able to calculate for more than two objects, in which case the equation I wrote is technically incomplete.  Students will figure out how to add a third or fourth object just fine once they have experience calculating for two objects.  In first year physics, complicated but precise mathematical notation obscures rather than elucidates meaning.  Sort of like any statement that includes the word "technically."

The AP Physics 1 exam famously has minimal use for numerical answers.  Only one of the ten revised "science practices", with which each AP Physics 1 exam question must align, includes calculating numerical quantities.  So while "here are two objects and their positions, calculate the location of their center of mass" is a legitimate question, expect this end-of-textbook-chapter-style problem to be rare.  But what else is there?  Think of the same kinds of questions that are asked about kinematics or energy:

* How would the center of mass position change if the left-hand object's mass were doubled?  If both masses were doubled?  If a third object were placed somewhere?

* Graph the position of the center of mass as a function of the mass of one object; graph the position of the center of mass as a function of time with this known external force acting on the system.

* Describe an experiment which will determine the center of mass position for this set of objects on a thin plank.  Now here's some data from that experiment; plot the data and use the slope of a best-fit line to determine the center of mass position.

All these questions start with the center of mass formula, but use the formula to make predictions, graphs, experimental conclusions.  And that's AP Physics 1 in a nutshell.

Why use energy bar charts?

The usefulness of graphical representations over straight-up equations and calculations for understanding energy concepts has been well established in physics teaching literature for years.  Yet, still only a fraction of physics teachers - especially at the college level, as reported to me by recent graduates - use such representations as an integral part of teaching energy.  

For most teachers I work with, their story parallels my own.  At first, reluctance to use energy bar charts seems to have three possible causes:

(1) I was never taught that way; I and my classmates understood energy with equations without trouble.

(2) It would be a LOT of work to change my materials not just to add in bar charts, but to de-emphasize algebraic algorithms.  And it doesn't make sense to do this work because...

(3) My current students are understanding just fine; they're getting answers right more often than not.

I resisted teaching energy bar charts for nearly the first two decades of my career - mainly for point (3) above.  For the most part, my students seemed to be learning energy without trouble.  The old calculational AP Physics B exam rewarded quantitative reasoning.  So I taught my class the most general form of an energy conservation equation I could:

W_NC = (KE_B – KE_A) + (PE_B – PE_A)

Students were taught to identify two positions A and B, take out any terms that were zero, plug in the KE and PE formulas, and solve.  This allowed students to get correct answers, or at least copious partial credit, for practically any Physics B problem you could imagine.

This algebraic formulation caused difficulty when students were asked to reason with energy.  Most students dutifully plugged in correct variables, or correct numbers for the correct variables.  But what they *saw* was a bunch of gobbletygook, as if the work-energy theorem were written in Klingon.  

Yes, I'm personally fluent enough in mathematical notation that I can quickly describe conceptually how a change in a physical situation would affect the calculation.  Physics Education Research has provided abundant, replicable evidence that the vast majority of students are nowhere near as fluent.  

(Some would argue that students in a college-level physics class should be good enough at mathematics to do advanced analysis with an equation this simple; after all, most of these folks are in a calculus class, and algebra of this sub-basic level was generally taught in 7th or 8th grade!  Yet, arguing what students should be able to do in the face of evidence to the contrary is not a recipe for success.)

When the AP Physics 1 exam came on line in 2014-15, its incessant demands for non-quantitative reasoning forced my hand.  I opened up the wardrobe to find and create energy bar chart exercises, labs, problem sets, etc.  And lo, a new conceptual world opened up Narnia-style.

Look, would I have ever taught Newton's second law without free body diagrams?  Of course not!  If you just teach "F = ma," then students plug in any old F to the equation.  If you tell them they've used the wrong expression or number for F, they'll pull another out of their tuckus at random.  But the free body diagram forces* students to represent all the forces acting, and thus to pay attention to why each force might or might not exist, before they do any math at all.  The diagram ensures that students can't just plug numbers into equations in search of being done - they have to do the problem right.

* ha!

The purpose of an annotated energy bar chart is identical.  With just an equation to work from, students are trained from birth or middle school to plug in numbers and solve; exactly what numbers they use don't matter.  But now, students have no choice but to describe briefly why they chose to include or not include each bar representing a form of energy.  The exact size of the bars isn't important - just as I don't demand a to-scale free body diagram, I don't demand a to-scale energy bar chart.  What matters is whether there are more or fewer bars for each form of energy, or whether there are bars at all.

And finally, the energy bar chart gives students a starting point to get them out of their "I can't do this" inertia.  Anyone in my class, no matter how weak, can start drawing a free body diagram or an energy bar chart.  If they pay attention to their annotations, they often catch their own faulty reasoning.  When they seek help from me or a friend, the discussion begins with the diagram rather than with mathematics.  It's difficult for a student to understand why their mathematical work is wrong - especially when the actual mathematical algorithms were done correctly, but the starting assumptions were incorrect.  It's simple for a student to see why a diagram isn't right, and then to redo the mathematics based on the correct starting point.

Proximity of the professor is a problem

Have you ever passed less than a meter from a working student's desk and had that student look up, see you, and ask a really basic question?  Especially a "question" that seems to be searching for the teacher's approval rather than for authentic feedback?

I had lunch with two art teachers yesterday.

James told us of the best of his undergraduate professors, someone who was legendary within the entire program.  Apparently, sometime in the middle of his three hour drawing intermediate class, the professor would walk out of class.  He'd walk down to The Corner for a coffee, returning with cup in hand maybe 45 minutes later.

At first James was taken aback, appalled, indignant.  "How could he leave us?  That's unprofessional.  We need his help!  How does this guy consider this "teaching?"

After a couple of times, James noticed what was happening.  James was a dedicated art student, someone who cared deeply about getting better at drawing.  So when the professor left, of course James continued to work diligently, alongside the other art majors.  

And so, James spent 45 focused minutes working on his own, without a safety net.  James didn't ask for approval when there was a decision to be made about his piece - he made the decision himself, and got on with things.  The professor wasn't there to offer advice, solicited or not; so James stopped worrying about what the professor might think, and instead advanced the piece the way he himself wanted.  When the professor returned, conversations with him became less of the tone "what do you want me to do next?" and more of the tone "here's my work, what advice do you have?"

Then James followed up with a thought about his six(!) children.  If James and his wife are in the room while the children are playing, they hear a neverending stream of complaints, requests for help, demands for justice, and so on.  The noise is deafening.  But, if the children are not in proximity to adults, in virtually every case they play in relative harmony.  Arguments are resolved quickly.  A kid who doesn't get their way either joins in with the others and does things their way, or just finds something else to do.  The adults in the house may get several dozens of minutes of peace.

Finally, Shari (proprietor of The Muddy Rabbit pottery, and ceramics teacher) said she often starts making her own projects during class.  Not only is she modeling appropriate technique, demeanor, and procedures in the studio, she is physically separate from the other students.  After a day or so, she says, learning how to throw clay on the wheel is a matter of playing around and finding out.  She's given all the advice she can - they simply need to practice, paying attention to what they're doing, powering through frustration, until muscle memory is established.  When she is working on her own project, she's close enough to answer questions posed out loud (whether or not the answer to that question is "keep trying!") and to notice when a student truly needs faculty intervention; but far enough away that students don't continually say "is this good, Mrs. Jacobs?" 

James and Shari were describing in different contexts why the ground state of my class consists of me at my computer in front of the room.  Students must physically walk to my desk to show me their progress or to ask a question.  When a student instead shouts a question, I ask them to come forward - you might not be surprised to know that this shouty student often stays put at their desk, seemingly having figured out either the answer to their question, or that their question wasn't as urgent as they had thought.

James said he's heard the term benign neglect to describe the technique of strategically ignoring his kids and his students.  Physics teacher Matt Greenwolfe adopted the term that I use, feedback inertia.

Whatever you call it, you're not letting your students down if you seemingly leave them alone for extended periods.  Be there for them... but only when they truly need you.