2026 Call for Jurors: Woodberry Forest Conceptual Physics Tournament, Sunday May 17

In my school’s conceptual physics program, we give cumulative written tests after the first and second trimesters.  In lieu of a final exam*, we are for the ninth time running the Woodberry Forest Conceptual Physics Tournament!  This is a competition for 9th graders, to be held the afternoon of Sunday May 17 2026. 

*No, to be clear to all, we’re not giving an A to the winner and an F to the person in last place.  That’s silly.  We’re just having a fun, competitive tournament, to determine a winner.  Jurors engage in discussion and conversation with participants about their problems.  Jurors then award scores and write comments for the participants; jurors aren’t assigning grades!

How does this tournament work?

On April 27, I will reveal a slate of three problems to the 70 participants.  These problems will be in the style of old AP Physics 1 “paragraph response” questions. Except, rather than just answer in a paragraph, the students will spend the month of May setting up experiments to provide evidence for their answers. By tournament time, each student will be expected to be prepared to discuss the solution to two of the three problems, with both theoretical and experimental support.

At the tournament, each student will participate in two “physics fights.”  Think of these physics fights like a miniature version of a graduate thesis defense.  Students will have a strict limit of two minutes to present their solution to a group of two or three jurors, who then will engage each student in conversation about the problem for five minutes.  The students are evaluated by the jurors not only on the quality of their solution, but also on their ability to discuss the solution, to confidently hold a conversation with the jury.

Importantly, jurors are explicitly instructed on their primary role – to find out how much the students DO know, not merely to expose what they don’t know.  

How do the students prepare?

Starting on April 27, all conceptual physics classes the rest of the year will be devoted to tournament preparation.  They’ll work together to set up experiments in class, they’ll be assigned to write up their solution as homework, they’ll practice presenting.  They’ll get intense instruction and guidance from the conceptual physics teachers, from their peers in the AP classes, from those who’ve been through this tournament before.

We need jurors.

The key, I think, to any class project is external assessment.  I and the other conceptual physics teachers will play the role of coach and advocate, always encouraging and helping the students to deepen their understanding of the problems and to improve their presentations.  Our relationship will be purely supportive, enthusiastic, positive.  

We can’t then turn around and grill these same students as examiners!  That’d be like our football team’s coaching staff refereeing the state finals.  Even — especially — if their officiating were fair, the coach-student relationship, both before and after the game, would be irrevocably compromised.

So we need jurors.  We can pay.

Would you like to come to Woodberry on May 17 to be a juror?  We’d ask you to arrive at 11:30.  We’ll have a meeting of all jurors in our beautiful dining hall over lunch.  

Then we’ll ask you to be a juror for a couple of hours’ worth of physics fights.  You’ll be partnered with several other examiners over the course of the afternoon, getting to know a diverse set of fun folks from all over.  When all students have presented their two physics fights (to two separate juries), we’ll gather the jurors for conversation, coffee, snacks, and their paycheck.

In any case, our goal is to be done by 3:30, or possibly 4:00 if there are logistical issues.  No later — our students will be attending the final seated meal with their advisors that night followed by study hall, so we can’t run late.

We will pay you $100 plus lunch for your time.  (If you’re coming from more than a few hours away, we can put you up on campus on Saturday or Sunday night – please let me know if you’re interested in this option!) I think you’d find that the camaraderie among the jurors and the engagement with the students will make the trip worthwhile.

Who’s eligible as an juror?

Anyone who has passed a college-level physics class.  This includes alumni of your advanced physics class, even if they’re still juniors or seniors in high school – we’ve had several teachers bring a caravan of students, and they’ve had an awesome time.  We’ve had local college or graduate students on juries, we’ve had parents, alumni, colleagues who teach other subjects, grandparents, friends… Anyone willing to engage in conversation about physics at the high school level, as long as you can recognize good and bad physics, we’d love to have you.  We are looking for a diverse juror pool, which especially includes diversity in age – truly, we want folks in their teens as well as folks in their 70s, and everywhere in between. When I ran the USIYPT, I found the mixture of undergraduate / graduate / professor / high school teacher / industrial physicist / retired physicist on the juror panel allowed some amazing relationships to develop.  I’d love to create a similar vibe here.

How can I sign up?

Send me an email via greg dot jacobs at woodberry dot org.  I’ll send you more information, including the three problems, and our current draft of the scoring rubric.

We would like to get 54 jurors – pretty much the first 54 who sign up.  I can’t wait to see some blog readers!  I’ll even introduce you and your students to my pet hippopotamus, Edna.

Mail Time! I just started teaching AP Physics 1. Can I also teach C mechanics next year?

Via the PGP message board, the question was:

I’m plowing through my first year of AP 1. Wow, so much prep! I’m intimidated by how good all the other physics teachers I meet are, but I hope to be that good soon. My admin wants me to pick up AP Physics C mechanics next year. I have such a stacked schedule and am prepping so much this year that I said no. But… how much more prep would C mechanics be? Is it an entirely different style of teaching?

So, I was in the exact same spot in 1998. School head asked me to teach C mechanics, I was barely keeping my head above water in what was then AP B, she said “you can handle it”… 

…and she was right.*

*She was right that I could handle it, and that it was the right move for me and the students. She was wrong about absolutely everything else she ever said or did.

Especially now since the 2025 changes, AP1 and C mechanics are the same topics and same style. You might have many of the same students, and teaching second year students who willingly come back to you is a great joy.  You can be more relaxed with your prep – with second year students, “here’s a rubber band, give me evidence of whether it obeys F=kx” with no further instructions, lab sheets, setup, or scaffolding is fantastic.  

P1 students need structure, routine, scaffold. Second year C students don’t. You’ll have more time in class than you know what to do with (though it won’t seem like that at first). Trust that they know how to learn physics.

Another year or two out, you might be chomping to convert to both CM and CE, which in 1998 I said I’d never do, but then loved so, so much.

One thing at a time.  For now, if you do nothing but run an advanced version of what you already did in P1, your students will be well served, and they should perform great on the exam.  Once students have the P1 fundamentals, they truly can do anything. 

Good luck!  

Setting up AP problems in the lab: 2023 Physics 1, KE vs SPE graph

A cart attached to a spring oscillates. This picture is part of the 2023 AP Physics 1 exam, copyright College Board

The 2023 AP Physics 1 exam posed an unusual question about a cart oscillating on a spring. What would a graph of Kinetic Energy vs. Spring Potential Energy look like, for the cart-spring system?

KE vs. SPE for the oscillating cart. The graph is a line with identical vertical and horizontal intercepts. From the 2023 AP Physics 1 exam, copyright College Board.

Well, okay, the question was phrased in a simpler way. The graph of KE vs. SPE was presented for students: The vertical and horizontal intercepts were the same, and connected by a straight line. But WHY should the vertical and horizontal intercepts be the same? That’s ’cause the maximum potential energy at the release point is completely converted to kinetic energy at the midpoint, making the maximum energies the same.

In the final part of the question, we drop a block onto the cart at the moment when the spring is at its maximum extension. What does the KE vs. SPE graph FOR THE CART-SPRING SYSTEM (not including the block) look like now?

Well, the maximum potential energy is the same as it ever was. SPE = (1/2)kx^2. Dropping a block on the cart at the maximum displacement from equilibrium doesn’t change the spring constant, nor the maximum displacement from equilibrium. So the horizontal intercept of the graph is the same as before.

What about the maximum kinetic energy? Well, the maximum potential energy converts to the maximum kinetic energy of the cart AND the block; so the maximum KE of the cart by itself is less than the maximum potential energy of the cart-block-spring system.

(How much less? On the exam question, the cart by itself had 1/4 the mass of the cart-block system; and the block and cart always move together with the same speed. So by KE = (1/2)mv^2 with v the same, the cart by itself has 1/4 the maximum KE of the cart-block together.)

Would this happen in “real life”? Well, of course it would. I got into a bit of trouble trouble in a previous decade for cheeking a bigwig who went on and on about how we must teach “real life” physics. I asked him, “Can you give me an example of physics that is NOT “real life”? I got elbowed by physics teachers with better political acumen, but they knew I was right – if we can’t set it up for real, then it’s not physics.

Cart on a track attached to springs in my lab

The Vernier sensor cart above is connected to two horizontal springs. Why two? Because I don’t have a useful *compressible* spring. But if I stretch two springs and attach them both, I get oscillations in harmonic motion that can be modeled as if the cart were attached to a single spring, as in the diagram at the top of the post. What is the effective spring constant of these two springs combined? I measured that by making a position-time graph of the oscillatory motion, finding the period, and using the formula for the period of a mass-on-a-spring. I found that the 0.28 kg cart oscillated with a period of 1.28 s, giving us an effective spring constant of 6.7 N/m.

Next, in the Graphical Analysis app, I clicked on the vertical axis and told the app to create a new calculated column called KE, which would equal 0.14 times the speed squared; and another new calculated column called SPE, which would equal 3.4 times the position squared. (You’ve gotta zero the position sensor at the middle of the harmonic motion!)

Then I plotted KE on the vertical, SPE on the horizontal, just like on the AP problem! I released from rest, let it go one oscillation, then added the 200 g mass you see in the picture and let it go one more oscillation. Here’s what I got:

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Isn’t it beautiful when Physics Works. 🙂

Demand that students write descriptions of forces. This method *works*.

Free body with the right force crossed out.
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A person pushes a block to the right. After the person pushes, the block slows down due to friction on a rough track. Draw a free body diagram of the block after the person pushes while the block slows.

Why do you think the conceptual physics student whose work is pictured above scratched out the rightward arrow?

From the very first day we discuss force, I insist that a free body diagram must include a list of forces, including the object applying and experiencing the force. This list must be in the format “W: force of earth on block.” That is, “downward force of earth pulling on block” might seem identical, but is not acceptable. “Force of ____ on ____.”

One of the benefits of this formulation I’ve observed over the years is I see way, way fewer fictitious forces than I used to. Before I demanded the list of forces, students would draw arrows labeled “force of motion” or “rightward force” or other silly things. Why? I mean, a LOT of reasons. They conflate force and motion, they think all forces must be balanced, they think they’re just supposed to draw arrows in every direction… I would explain again, but students would get it wrong again. And again.

Nowadays, in the first few days of studying forces, students still put these fictitious forces on their diagrams. Because they put crazy things on their list of forces, too, now I have a targeted explanation that students tend to understand in context.

They write a rightward “force of block on track.” I remind them that all forces must act ON THE BLOCK.

They write “force of the block moving to the right.” I remind them that all forces must be written as “force of [object] on [object].”

They write “force of push on block.” I ask them if a push is an object. It’s not. So the force of the push does not exist.

They write “force of person on block”. I remind them that all forces other than Earth require contact – the person was in contact with the block previously, but not anymore!

They write “force of motion on the block”. I ask them if motion is an object. Oh, motion is NOT an object. So the force of motion doesn’t exist.

We are now 1.5 months into the study of force. The student whose diagram is pictured above likely has been through most of the above conversations with me. So, on their problem set, when they reflexively drew a rightward arrow for whatever reason… they stopped to consider how to write this force in a list. They realized that they couldn’t write this force in a list. So they scratched out the rightward arrow, and got the free body diagram right. Yay.

Free live fluids demonstrations Tues Jan 20, 7:30pm EST

The Notre Dame “Remote Teacher Collaborative” is sponsoring a free hour-long show for physics teachers.  Tuesday night, I’ll be doing a series of quantitative, interactive fluid mechanics demonstrations in my lab.  The predictions and experiments will be aligned with the AP Physics 1 fluids unit, but are also perfect for dual enrollment physics, honors physics, college prep physics, actual college physics…

If you’d like to join, see the note below from Erica Conley Shannon, the session organizer.  When you register, you get the zoom link, and then after the session they send out professional development hours acknowledgement.  

Should be fun!

greg

From Erica: Here is the link to the Remote Teacher Collaborative on our Page.  Session descriptions for all of our sessions can be found here.  The session is free and open to all.

Remote Teacher Collaboratives

The registration link is halfway down.  Teachers not in our program register as a “Non-Program” School.

Collaboration incentive and lab cleanup

Just thought I’d pass along an observation from my class today. Our “order of work” consisted of:

  • Two “Physics Classroom” concept builders about force and motion
  • Test and quiz corrections
  • Lab cleanup
  • Work on tomorrow’s assignment

Three of my nineteen students in D period are well ahead of everyone else. They finished the concept builders quickly, and are already done with corrections. The lab had been left quite the disaster area before winter break, though, so they had plenty of cleanup to do.

At this point in the year, these 9th graders know well they’re part of a team learning physics. When I gave these students specific lab cleanup tasks, they not only didn’t complain, they willingly and kindly jumped to it.

Of course, most everyone else in the class was still struggling with the force and motion concept builders. “Grrr, why is this wrong? The only force is to the right, it should be moving right!”

The three on lab cleanup detail didn’t really stop cleaning. But they did show more significant that usual interest in helping their classmates.

Everyone knows that collaboration according to the five-foot rule is encouraged and expected in class. But even the most community-oriented students feel like they must prioritize their own work, their own understanding, before helping others. Especially when others keep making the same mistakes again and again.

Today, though, those fastest students didn’t have their own work to prioritize. They had lab cleanup to do. They were sorta happy to help, but still, it was lab cleanup. No way out of lab cleanup, it’s a drudgerous task that needs doing.

Except. They knew that if they were actively and appropriately helping a classmate rather than cleaning, I wouldn’t complain. And so they became teaching assistants, moving throughout the room in between carrying carts to the cabinets.

I didn’t have to say a word. These three students did eventually finish straightening the lab, but they also provided better hints, tips, tutoring than I possibly could have.

What’s wrong with this free body? Conceptual physics quiz question

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A person pushes a cart to the right on a level track.  The person lets go of the cart, and the cart moves to the right at constant speed. 

A student is asked to draw a free body diagram of the cart after the person lets go, and produces the diagram shown.  Name three things specific things that are wrong with this diagram.

I ask this on a quiz about a week into our conceptual physics forces unit. It’s certainly good pedagogy to have students identify common errors! It’s also a bit cathartic, in the sense of “don’t get mad, get even.” I’ve read numerous bad free bodies, now it’s time for the students to walk a kilometer in my shoes.

What answers would I accept? Any brief reference to of the following is fine:

  • The person has let go of the cart, and so is not currently touching the cart. All forces other than the force of the earth require contact, so Fp is incorrect.
  • There’s no such thing as the “force of motion”. Motion isn’t an object. Only objects can exert forces.
  • The force of the cart on the track exists, but should not be included on a free body diagram of the cart. All forces here must act on the cart.
  • The diagram is missing the force of the earth on the cart. This is the force that is allowed, nay required, to act without contact.
  • The cart is said to be moving at constant speed, so forces must be balanced. The diagram shows unbalanced force to the right.

There you go – five things wrong with the diagram! I’m happy for students to mention three, of course. The purpose of the quiz is less to play “gotcha!” as to provoke a discussion of bad free body diagrams in a context in which the students very much care.

A catalog of non-grade incentives

As I was talking shop with a few colleagues last week, a non-physics teacher shook his head and said, “Greg, your class has so many effective incentives that have nothing to do with grades!” As he listed those he knew about, I realized that (a) I hadn’t even thought of some of these as “incentives,” though that’s what they are; and (b) he and others would probably be interested in a more thorough list.

Before I begin a catalog, though, it’s important to consider what I’m actually attempting to incentivize. I don’t assign grades in AP Physics – everyone gets an A-, and then their final grade is adjusted in the summer based on their AP exam performance. In conceptual physics, I haven’t figured out how to eliminate grades yet, but I try to be as translucent as possible. Point is, my incentives are tuned to my class goals: work hard, take care of your classmates, get better every day. And those goals are best achieved when the class culture is supportive, where we do serious work and collaborate effectively.

Incentives I use in my 9th grade classes:

  • Music: If everyone completed an assigned problem set, we can listen to music during lab time. (If someone didn’t do the problem set, the class isn’t in trouble, of course! Not their fault! But no music.)
  • Whoever gets the top score on the daily quiz gets to choose the music genre on Pandora. (If there’s a tie, I roll a die to see who chooses. The winner isn’t allowed to ask a friend or pass the honor to someone else; no one is allowed to lobby, complain, groan, etc. I’ve had conceptual students tell me that they started taking the daily quizzes seriously because they wanted to choose the music.)
  • Name on the board: I put numerical scores on problem sets in both conceptual and AP. Even in the everyone-gets-an-A- AP class, students have been previously conditioned to care about scores, to strive for high scores. Grading problem sets communicates that I’m paying attention to their work, that every assignment does in fact matter. However, for a particularly poor or incomplete assignment (in both AP and conceptual), I don’t bother with a very low numerical score – I put the student’s name on the board. This indicates that they must come to an extra-help period to correct what they missed. I’m not trying to punish or shame anyone! Yet time, not grades, is the currency my students respect. When I see compounding errors, insufficient attention to fundamental details, or dashed-off assignments without comprehension, the name goes on the board. A student who’s submitted such a problem set either needs my help, or needs time to pay careful attention to the work. I’ve had years of AP students tell me that they take their problem sets seriously because they do not want to see their name on the board; and that they check each class day as they enter, getting a bit of a dopamine hit if their name is NOT on the board.
  • After a test, pretty much everyone’s name goes on the board. When they complete their test corrections, they may take their name off the board. (Test corrections are done on a blank copy of the test. Students may see their actual original test when they finish corrections. For conceptual students this is a significant incentive at first, because they want to see their grade and what they missed. In practice, though, most students don’t ask to see the original – the corrections process has given them the feedback they need and want.)
  • Exemptions: On occasion, I’ll give a student an “exemption” card with their name on it. This can be turned in in place of a forthcoming problem set. Again, I’m using time as currency. A top score on collaborative problem sets in conceptual physics, or top performance on a problem set / quiz combination in AP, indicates to me that such a student might not need the same amount of practice as other students. Or at least that they’ve earned some time away from physics.
  • In each trimester, conceptual physics does a series of quizzes I call the “daily quiz challenge.” I publish standings (without names except at the top). The top four each get an exemption, or a milkshake at the school snack bar. Their choice.
  • Candy: My seventh grade civics teacher used to throw out small pieces of candy as fish to dolphins. I channel him regularly. The first group to finish data collection, the first student to finish lab analysis, the best brief summary of a problem when we’re doing what the modelers call a “board meeting“, or an extra-close match of experiment to theory might earn a piece of candy. A parent once told me, “my son was so nervous about your class, but he says you gave him candy last week, and he seems so much more confident!”
  • Milkshakes: Once or twice a year, I offer snack bar milkshakes as a prize for making a particularly important prediction. “To double the cart’s constant speed, how should I change the force with which I pull?” “I double the speed at which I launch this sphere horizontally. How does the time in the air change?” Correct answers are rare enough that this doesn’t put particular financial strain on my budget.
  • Consultation Day: I announce these in advance, usually for Friday’s or (we are a boarding school) Saturday’s class. Students who have finished all required corrections and have completed a reasonable number of lab exercises that week are excused from part or all of class. This is especially effective for a 1st period class. It’s amazing how many folks are willing to come work with me during extra-help time or a free period when the reward is to leave early. It’s not necessarily rational! Often a student will enthusiastically spend more time with me earning their way out of class than they would have spent with a scowl on consultation day itself! But no one said 9th graders were rational. <shrug>
  • In AP only, the must-pass fundamentals test: The AP class is opt-in and gradeless. Students may opt out at any time; I may also counsel a student out of AP and into conceptual if they aren’t making a good-faith effort on their daily work, or if their test performance demonstrates that passing the AP exam would be as likely as the Bengals winning the Super Bowl. I am very careful to keep students in the class as long as possible, such that when I occasionally do counsel a student out, that student’s reaction is one of pure relief. But one time per year, I make an explicit performance requirement to remain in the class. We take a 30 minute, 30 question “fundamentals” test right before Christmas break. This includes only very basic questions, including straight-up recall (what is the horizontal acceleration of a projectile?), or simple one-step reasoning questions (Here’s a projectile, at which position is its horizontal velocity greatest?) The passing mark is 80%. Students who don’t pass must take a different version again at the end of the first week back from break. Then again if they don’t pass. And again. I’ve never had anyone who didn’t pass before spring break (Mar 1 or so). It’s sometimes taken nine attempts, but they’ve always passed. And if they truly can’t pass this test, they don’t have a chance at answering the far more complex questions on the AP exam.
  • Nacho Party: The night before the trimester exam, I host students at my house for nachos. (Decades ago when I taught at day schools, families would take turns hosting these physics parties.) The ticket for admission to the party is to have all corrections finished and to do the review packet. Then at the party itself, students correct what they missed on the review packet. A “grab bag” of enrichment problems is available for those who finish the review packet.
  • Skee-ball: For each completed review packet correction or grab bag problem, students earn a token for one game of skee-ball. (Yes, seriously, I have a skee-ball machine in the basement.) Occasionally colleagues have given me a frowning upon hearing that students are <gasp> having fun the night before the exam! Horrors! I suspect what they’re really frowning at is how much better and more enthusiastically my students prepare for their physics exam than e.g. math or history. And how much better my students perform.

Contexts in which math does and doesn’t matter

A car begins at rest, then speeds up to the east for 10 s with an acceleration of 2 m/s/s. (a) How fast is the car moving after the 10 s? (b) How far does the car move in 10 s?

What do you think of this response for (a)?

I solved (b) to find d = 100 m. Now use d = v2/2a because the car is speeding up and we are looking for speed.* Then:

* In conceptual physics, we have three equations for distance. Students are taught first do determine whether speed is constant – if so, use d = vt. Then if speed is changing, use d=(1/2)at2 if time is part of the problem, or d = v2/2a if speed is part of the problem. We only deal with objects speeding up from rest or slowing down to rest, so these latter two equations will always be valid.

  • d = 100 m
  • v = ?
  • a = 2 m/s/s

100 = v2/(2), so v2 = 50 and the speed is 14 m/s.

Harumph! The student forgot the 2 in the denominator, then bungled both the cross-multiplication and the square root. Shoulda been v2 = 400, so v = 20 m/s. Kids these days and their fuzzy math. <eye roll>

On a problem set, I gave this response full credit. They used the correct equation; they wrote a chart with units clearly stating what values for d and a they were using; they communicated where they got the d = 100 m. They got an answer with units that is reasonable for a car.

(Had they told me the car was moving 400 m/s, I’d feel differently. The skill of recognizing the meaning of numerical answers is important. Students have a fact that 1 m/s is about 2 mph, or 4 kph; and they have learned the speed of sound. Supersonic cars are not a normal thing.)

Physics is emphatically not a math class. In conceptual physics especially, I work with students whose relationship with fractions is as mine with relativistic quantum field theory. I can’t avoid such students having to use basic math. However, I can continually emphasize physics problem solving skills over the correct answer, or over mathematical manipulation. This student communicated their physics understanding and problem solving methodology. If I say “minus one point” here, the student feels a bit beaten down; giving full credit doesn’t cause the end of the world. It’s fine. I’ve not yet been struck by lightning for giving credit to an incorrect numerical answer.

But Greg, something is WRONG in your physics class! Right answers do matter! If this student were building a bridge, the bridge would collapse!

Well, this is why we don’t employ 14 year old conceptual physics students in the bridge building industry. My analogistic reposte: when a pitcher on the JV baseball team strikes out a batter, we say “yay”, not “he’ll never make it in the major leagues with only a 65 mph fastball, harumph!”

So where, if ever, do right answers matter? In the lab. So let’s reframe this question as an experimental exercise.

A cart is released from rest at the top of a 12 degree track on which the cart has an acceleration of 2 m/s/s. How fast will the cart be moving when it has traveled 1 meter?

It’s the same question, but one that can be tested in the back of my room with a smart cart and a motion detector. I ask students to show me their experimental prediction before they touch the equipment. No matter the student’s reasonable prediction (i.e. not 400 m/s!), I pass them along without comment as long as I see the table with units and the correct equation.

The student who did the math wrong will show me the smart cart data and look confused. (Or they’ll stay in the lab for 20 minutes futzing until I insist that they come show me what they’ve got.) You predicted 0.2 m/s, but that’s not within 20% of your prediction of 0.5 m/s. Let me look at your work. Oh, see here! You did your fractions wrong. Here’s how to solve this kind of equation. Try again and see if that matches what you measured!

Yes, I’m aware that this student has been taught many times how to plug in numbers and cross multiply. I’m not teaching them any more or less effectively than their previous math teachers. But suddenly they care about doing the math right, because they want the right answer.

And that’s the point. We don’t learn by doing, we learn by paying attention to what we do. In the context of the problem set, the student didn’t pay that much attention to the math, and is quite used to the teacher taking off points in math class. In the context of the lab, though, the consequence of bad math is not the teacher taking off points; the consequence is a lab exercise that doesn’t seem to work. It’s the universe saying “you’re wrong,” not mean ol’ teacher.

What generally happens next? The student pays attention to the math, gets it right, and moves along. Or in rare occasions the student has an actual epiphany about how fractions work. Either way, ignoring math silliness in the context of practice problems turns out okay. Everything is going to be just fine.

Context of feedback, and writing notes on student work

Even though I tell physics teachers never to write feedback on student work, I did just that at the beginning of the week.  Why did I diverge from my own advice?  And, did it work?

Usually, Rule 2 of teaching (Your students don’t listen*) informs my manner of providing students feedback on problem sets or assessments.  I grade and return problem sets reasonably regularly, putting a score out of 15 or 20 points on each paper.  Of course I grade tests carefully.  But I never write any individual feedback on problem sets or tests.  Why not?   It takes a long enough time to grade these items while writing nothing but the final score.  It takes orders of magnitude longer to write something like “you didn’t use a fact” or “your fact talks about the vertical axis, but your connection doesn’t mention the vertical axis!”  But we all know that students don’t generally read such feedback carefully, except to figure out whether they can argue for more points.  That’s rule 2.  The effort to provide written feedback on graded work is noble, but fruitless.

*That’s okay, mine don’t listen to me, either

Where do students learn from their mistakes, then?  On corrections.  Students do thorough corrections on every assessment, in which they show me their justifications, and I only check them off as correct if they are exactly right.  If they’re not exactly right, I say immediately – with the student standing in front of me – what’s wrong and how to fix it.  Students listen carefully in this context, because they want to get the correction done… and they have to process and use the feedback right now without downtime for the feedback to be consigned to their brain’s metaphorical attic.

We’re just back from Thanksgiving break.  My conceptual physics class all have had plenty of opportunity to practice and understand how responding to physics questions works: use facts, equations, or calculations on every response.  Use only the facts and equations on our fact sheets, nothing else is allowed as a starting point.  You’re not supposed to know the answer, you’re supposed to use the facts to discover the answer.  After three months of practice, students aren’t expected to get every answer correct, but they are certainly expected to apply these straightforward methods to every problem without exception.

The first assignment after break was to do two corrections from the trimester exam.  That is, pick a problem (any problem) you missed, and use facts/equations/calculations to explain how to do the problem right.  Collaboration according to the five-foot rule was encouraged.

As you might expect, about a third of this 9th grade class reverted to statements like “the answer is B because…” Or they reverted to writing facts without connections.  Or they didn’t read that the question asked about current, but their response was all about voltage.  Or they wrote “I can’t find a fact that answers this question.”  Booooooo.

Interestingly, after students turned in the assignment but before the assignment was returned to them, all students had an appointment with their advisor to see and discuss their marking period and exam grades. So, I tried varying my feedback approach to take advantage of the context of this particular assignment.

I hand-wrote direct feedback, such as:

  • “Good fact, but you didn’t refer to the fact in your connection.”  
  • “You did not write a fact from the fact sheet.  We’ve been in class for three months. This is not a matter of physics being difficult, but of you not following directions.”
  • “Great work setting up this calculation, you just did the math wrong – no big deal, I’m counting it as good enough!”  

Generally, the students who are working in good faith need positive reinforcement that they are making progress, even if they occasionally get wrong answers.  Generally, the students who are passive-aggressive about their physics assignments need a (figurative) good swift kick in the tuckus.  

Even if they sometimes present as lazy, pretty much all my students truly want to do well.  They will tell their parents or advisors, in a one-on-one setting, what their academic and personal goals are, which include positive engagement in physics class.  To make progress, my 14 year olds often need to confront the disconnect between these articulated goals, and their actual performance in the moment.  

The comments I wrote were, generally, effective – in the week since I wrote them, I’ve had several of the most focused and productive classes of the school year.  Those who received positive comments held their heads up a bit higher, even when they got questions wrong in class.  Those who received rather direct negative comments changed their behavior, and thus learned a bit more and built more confidence.  

I still don’t recommend giving students specific written feedback on every assignment!  Why was this particular round of feedback successful?  For the “he noticed” effect.  Students are conditioned to think of daily assignments as routine and of minimal importance.  The fact that I noticed their work, good or bad – and that they see oh, boy, I clearly have been noticing all along – demonstrated in no uncertain terms that they can’t hide, that their assignments matter.  It’s easy to write a bunch of baloney to turn in to a faceless robot for a grade; it’s not as easy to write baloney that they know will be read carefully by Mr. Jacobs, who will subsequently comment pointedly on said baloney.