Open-Internet Quizzes

All my quizzes are open-internet* AND students may reattempt quizzes if they think they can do better. Yesterday, I was cruising around the room and saw this on a kid’s screen:


Searching for “how do i find the angle of the equilibrium force”.

I figure one of two things is happening here:

  • kid has zero idea how to find the problem and is searching for a howto online
  • kid wants to confirm that what she’s doing is correct

My gut says it’s the first scenario. As I kept moving around through all my classes, I also spotted kids copy/pasting the whole question, hoping it was published online (gotta admit to doing that myself). One kid was really pissed to learn the result he used to answer his question was incorrect. In his words, “Google lied to me!”

This Googling led me to wonder what my kids search for on open-internet quizzes:

myavatar mgolding
Would love to have a list of what all my kids google for during my open-internet quizzes.
3/20/14 10:58 AM

Oh, it’s on. I have a few different plans here:

  • classifying the kids’ queries because I’m curious
  • helping them search better
  • planting Easter Eggs on Yahoo Answers (yeah, I just want to mess with them a little)

The first step is to intercept the exact queries. John Burk pointed me toward the idea of a Google Form that hands off to a Google search query. I’d collect the data in the form and the kids’ searches would be automatically run. The key lays in convincing kids that me seeing their queries will in no way harm their score nor will I change my practice because of something I see. They need to believe me to use the form.

The second step is to learn if the query led to a result they used to answer the question.

More on this story as it develops.

*my quizzes are taken on Moodle, so the kids’ computers are online for the quiz. Also, we’re a 1-1 laptop school.

Exam Review That Doesn’t Suck

It’s nearly exam time (hey, no complaining, y’all with a month or more of school left made me jealous last August!). In the past, I’ve been a huge proponent of Waterfall Trivia and math stations as review techniques. Both helped me wrangle large, unruly classes that didn’t really want to review for an exam or test. This year I have a blessing and a curse wrapped into one: my students would actually prefer to sit and listen to me recap the entire semester over 2 or 3 days. “Re-lecturing” is just not valuable in my opinion. The kids are passive, so they’re not likely actually getting anything new from the activity. I’d prefer activities where the kids do most/all of the in-class work — Quadrant I in my chart below. Some teachers aren’t so lucky as to have such academically-minded students, so their review activities need to get the kids who don’t want to, working — Quadrant II.

the matrix of doom!

My criteria for a good review activity with this batch of kids:

  • avoids cutsey gimmicks
  • hits >= 80% of content covered this semester
  • allows serious problem-solving in class
  • has me not recapping the whole semester at the board for n days.

With my criteria in mind, here are the best ideas shared by my Twitter peeps.

Recitation Problems from Kelly O’Shea. Kelly writes:

About two weeks before the end of the semester, my students get a big (usually 24 pages), intimidating packet. It has one problem per student*, and the problems are problem+blank-page type of questions (that is, juicy ones that require multiple steps without breaking the question into parts that would structure the work for you). They tend to cover most of the main skills, but especially the ones that my students have found most difficult.

When they get to class the next day, we pick letters A through however-many-students-there-are. Then I give them my pep talk about how they should choose their problem. Whichever problem they choose, they will get to present the solution the class. They will have to become an expert on that problem. So I encourage them to pick the one that looks scariest to them. Pick the one that you would least like to see show up on the exam. Pick the one that will be hardest for you (it will be different for different students, of course).

Recitation Problems hits all my criteria without adding a ton of stress to the kids in their last week of regular classes.

Math Basketball from Dan Meyer. Dan writes:

  1. You bring in a set of questions related to the previous two week’s instruction.
  2. You put up a question.
  3. A kid stands up with an answer, either correct or incorrect:
    • If it’s incorrect, the student sits down, reworks the problem, and you wait for another student to stand.
    • If it’s correct, the student takes two shots with a miniature basketball into a lined trashcan. You award points according to a) the student’s distance from the trash can, and b) the competitive mode you’ve selected below.
  4. Repeat.

Review Activities Aplenty from Becky Rahm

I wound up doing math stations because they’re pretty easy to set up and help me carve out time to ask individual questions. Here’s the setup:

  1. Print a set of problems for about 10 minutes of work on a sheet of paper. Repeat for each topic. Spread the problem sets around the room. I taped mine to cabinets, Julie Reulbach uses acrylic frames (way cooler).
  2. Print answers and hang them in one spot near you.
  3. Set a 10 minute timer tell students to choose a station with <5 people already there, work problems, and check answers at will. If they can’t get their problems answered by a classmate, they stay with me until station time’s up or question is answered.

Stations are easier to set up if you collaborate with a colleague.

global math logoI’ll be sharing, along with Matt Vaudrey, about Exam Review That Doesn’t Suck on Tuesday, May 21 at the Global Math Department. Join us! It’s completely free and online at 9pm Eastern / 6 Pacific.

Hockey Puck Ninja Problem


My colleague is obsessed with ninjas in the same way I’m obsessed with superheroes. Whenever she gives her kids a challenging problem, she calls it a Ninja Problem. Students who gain ninja status in her class basically earn bragging rights. My first Ninja Problem went like this: “Is it possible to knock the goalie back into the net with a hockey puck? If no, what would it take?” (Hint: you can do most of the work using conservation of momentum.) Mad props to xkcd what-if for the inspiration.

H’s Hockey Puck Analysis

My student, H. took this Ninja Problem on with a vengeance.

After about 24 hours of thinking time, I shared a video with him that a Twitter pal shared with me. Fun and inspiration ensued.

Here’s his response:

Whoa! That’s crazy. I figured out that in order for a hockey player weighing 151 lbs (126 lbs for average 15 year old and 25 pounds roughly for average hockey gear (68.4924479 kg)) to be pushed .5 meters into a hockey goal in one second, a hockey puck must be launched at the average of the average velocity of a hockey puck (80-90 mph which I chose 85 mph (37.9984 m/s)) and after I calculated the volume of the hockey puck and its required mass, I found that the hockey puck must weigh 4.05729254 grams per cm^3 or .469969705 kg [ed: which is about 5 times heavier than a typical puck]. This means that it closer to Krypton and between Krypton and Yytrium. And in that video I think that guy was moving a little more than .5 meters per second haha. Thanks!

And 5 minutes later:

Whoops I have made a mistake! I multiplied took half of something while multiplying the other side by 2. The real answer is a hockey puck is needed to be made out of samarium or iron.

We talked through the effect of the goalie bracing against the ice (which H ultimately discarded because he didn’t know how to calculate for it), which made me wonder if he’d read the xkcd what-if answer. He hadn’t! When you get rid of bracing, it becomes much simpler to push the goalie back into the net.

N, K, and J’s Solution

This group of students, who elected one to be the star of the video, did a great job of separating the realistic scenario (which they quickly dismissed as implausible) from the hypothetical.

Implications for Physics Teaching

Mythbusters has made asking “what would it take?” fairly normal. A lot of my students understand the general approach of “ok, this thing is impossible as we’ve constrained it, so how could we reframe the situation so it’s plausible?” xkcd’s what-if extends on that. In fact, the hockey puck answer starts off with this gem:

This can’t really happen.

It’s not just a problem of hitting it hard enough. This blog isn’t concerned with that kind of limitation. Humans with sticks can’t make a puck go much faster than about 50 meters per second, so we’ll assume this puck is launched by a hockey robot or an electric sled or a hypersonic light gas gun.

Because high school physics often includes oversimplification to the point of absurdity, the “what would it take?” mechanism helps kids latch on to real problems in meaningful ways.

Points going forward:

  1. Teach the kids estimation & rounding skills back-of-the envelope calculations, which don’t require such precision.
  2. Find or write more of these questions!
  3. Figure out how to engage more kids with Ninja Problems. This problem seriously engaged 5% of my students. I’d be thrilled if the number were closer to 20%. In Doing Whatever a Spider Can, I promised to get kids describing their assumptions more regularly. So far, I haven’t. Ninja Problems may be a nice way to engage kids in this process.

Force Tables: Staying Organized in Physics

[Earlier this week, Tina asked me my blog’s name. Truth is, I never named it. Sure, I bought a domain but I never got around to branding the blog with the same name. So, what’s up with the domain name? Kalamity Kat was my grandfather’s WWII aircraft, a PBY-5A Catalina flying boat. He and his crew were shot down while rescuing downed fighter pilots out of Tokyo Bay.]

Physics class. The topic is forces and my kids were struggling to solve problems like this:

A student of mass 63.1 kg decides to test Newton’s laws of motion by standing on a bathroom scale placed on the floor of an elevator. Assume that the scale reads in newtons. Determine the scale reading when the elevator is accelerating upward at 0.7 m/s2.

or this:

A basketball with a mass of 0.4 kg is being pushed across a gym floor with a horizontal force of 2.2 Newtons. The coefficient of kinetic friction between the basketball and the floor is 0.2. What is the acceleration of the ball?

Struggling, that is, until I hit upon a way to organize their thinking with a “force table”.

this is what I've been calling a force table // yeah, I realize there's lab equipment with the same name

Students fill in the table like it’s a Sudoku puzzle. I think the hardest part now is getting the free body diagram correct. Ooh, just to be sure they know what’s up, I’ve been stressing the importance of completing the last column with justifications.

I like to imagine that all the physics teachers out there trained in physics education went to grad school classes with titles like “How to Teach Kinematics” and “Methods for Helping Kids Who Suck at Math”. In these imaginary courses, y’all received the keys to helping kids past the hurdles of difficult math or “there’s no formula for this, it’s a problem-solving process”. Wait. What? You didn’t have these classes? Then how the heck do you help kids problem-solve? Please share your own organization routines, I’d like to learn from you.

Doing Whatever a Spider Can

a scientific paper on the most unscientific of topics

Do you remember this scene from Spider-Man 2 (2004)? A NYC subway train hurtles toward imminent doom, unless Spidey can stop it. Is it plausible for spider silk to stop a moving subway train?


Suppose a man bitten by a genetically enhanced (or irradiated, depending on the origin you like better) spider can acquire the strengths of a spider proportional to his size. Next, suppose the scene depicted in a popular Hollywood film can give you some clues about the physics scenario afoot. Do that and you have “Doing whatever a spider can” by M Bryan, J Forster, and A Stone.  The paper was published 31 Oct 2012 in University of Leicester’s Journal of Physics Special Topics Journal. This stuff is golden1:

Screen Shot 2013-02-26 at 11.07.12 AM

Here’s a top view from the movie:


I want to teach my own students to describe their assumptions as well as these students(?) did in building their model2. What’s a good way to go about doing that work?

  • Demonstrate it in my own work? Build my own examples and walk through my assumptions.
  • Learn from pros? By getting kids reading papers like this one, even if we stop after the model parameters section.
  • Practice it? Have the kids analyze situations within their own level of physics. This I’ve tried and found to be incredibly painful. I’m willing, here and in public on my blog to commit to having my kids practice assumption-describing daily for 3 weeks. I’ll report back with results.

h/t to Leah Kazantzis, with whom I have the pleasure of teaching!

1 What’s that you say? You don’t teach physics using superhero examples? Oh, you’re missing out.
2 Enough of my friends teach using Modeling Physics that I expect to hear that idea thrown out here. That’s ok, but I’m looking for other stuff, too.

Intro to Projectile Motion

or, How I used Noticing & Wondering in Physics

Last week at Global Math Department, we learned from Max Ray (@maxmathforum) about using Noticing & Wondering. As with all the best Global Math presentations, I heard from folks who used the technique the very next day. I always seem to run a little slow compared to my Tweeps, so it took me a few days to find a good entry into my physics classes.

I started here:

Here’s my teaching setup, courtesy of Max:

  1. Ask the class to view the clip with this question in mind, “What do you notice?”
  2. Give them 1 minute to write individually, 1-2 min to discuss in small groups, then 3 minutes to share the best noticings.Here’s a picture of my 1st period class’s list.
  3. Ask the class to think in physics terms, “What do you wonder?” Again with the write-discuss-share thing. Here’s my 1st period class’s list.

I asked them which they wanted to pursue, height of the cliff or acceleration due to gravity. They liked gravity. After we estimated cliff height (which involved the search: “how tall is Wiley E Coyote?”) and the dust settled, we found g was about 3.2 m/s2.

When I picked this clip, it was because it reminded me of this, and the gravity question hadn’t even entered my mind:

Holy cow, this N+W is the good stuff. Kids were engaged, the framework kept us on task, we found a great physics problem I’d never considered, and I had an excellent entry into projectile motion.

Designing Ranking Tasks

I think the Ranking Task has room in your science or math classroom. I’ve run across a few in texts, on concept inventories, and in Modeling Physics materials but never made any for myself. “Hold your horses, Megan,” I hear you saying. What?! You’ve never seen a ranking task?

Officially, “Ranking Tasks are an innovative type of conceptual exercise that asks students to make comparative judgments about a set of variations on a particular physical situation.” Let me give you an example from Kelly O’Shea:

Rank these situations from greatest to least based on which shows the greatest displacement during the timefrom 0 to 10 seconds. Use the > and = signs, but do not use the < sign.

Here’s the brilliance I see in the displacement question Kelly asks. Say you’re a freshman in my physics class and you just learned the distinction between displacement and distanceI ask you to rank A-F in the above image. I imagine this internal dialogue (monologue?):

  • A and B look the same but I’m guessing that 25 on the y-axis is important.
  • C and D are straightforward displacements, the “easy” ones.
  • Good gravy! What am I supposed to do with E?
  • Whoa Nelly, F is even worse than E. I need to check the definition of displacement.

There’s understanding a definition then there’s applying that definition. Do you love Ranking Tasks yet?

I tried writing my own, wasn’t happy with the results, so I went for a walk on the newish Atlanta Beltline. We saw some amazing art, a skatepark, and spent time with family. Yeah, winter break rocks.

That grown man on the bike? My brother.

But I digress…

When I got home I realized what I was doing wrong — I tried making the ranking task without a clear idea of exactly what I was testing knowledge of. Wait, what? You mean I hafta think this out before I start drawing graphs? Oh okay…

  1. Draw about 2 items that are straightforward applications of the definition/idea being ranked.
  2. List the learning goals and common misconceptions.
  3. For every item in #1, design a picture or graph to address it.

I’m a rank n00b at these Ranking Tasks, but the Amazon writeup had good-sounding advice I’ll include here, too.

The basic structure of a Ranking Task comprises four elements:

  • a description of the physical situation, including any constraints and the basis for ranking different arrangements
  • a set of figures showing the different arrangements of the situation to be compared
  • a place to record the ranking of each variation
  • a place to explain the reason for each ranking choice

I’ve seen a lot written about Ranking Tasks in physics. The book I referenced above is specifically for physics, but why couldn’t these work in math? Off the top of my head: rank these fractions, rank these irrational numbers, or rank these radical expressions without evaluating directly.


Global Math Department in 2013 is gonna be hot! Join us Jan 8 for an Ignite-style meeting. Teachers will take the stage for 5 minutes each, armed with 20 slides auto-advancing every 15 seconds. The topic? My Favorite classroom ideas.

Jan 8: Global Math Department: My Favorite Ignited

What Do You Notice?

Earlier this week, I asked for feedback on the Lens Lab I’d written for physics. Kelly, David, and John helped me focus my thinking with their comments. I want to tell you now about how I incorporated some of the comments. It all began with something I learned in St. Louis at Twitter Math Camp.

The Activity

Given a large magnifying glass, and a look at the image formed of objects located outside our classroom window, I asked kids, “What do you notice? Be specific.” Here is one group’s noticings:

Next, I armed each kid with a marker and sent them on a gallery walk. If they spotted something interesting on another board, they put a check. If they disagreed, they put an x.

Crediting My Sources

This idea is part of a strategy I learned from Max Ray this summer at Twitter Math Camp. From his blog:

The strategy we call Understand the Problem: Included in Understand the Problem is the core activity I Notice/I Wonder, which gives an entry point into the problem to students of all levels, but which can be perfected and improved even by expert problem-solvers (see, for example, the world’s hardest easy Geometry problem). I Notice/I Wonder begins to orient students towards recognizing givens and constraints, identifying mathematical quantities or objects in the problem, and describing relationships among them.

Based on feedback from Kelly O’Shea, I used “I Notice” to open a lab this week. She suggested I begin with a demo, which I did (hold a magnifying glass up to form an image from the window on a sheet of paper). Then, she suggested I move on to:

Ask for observations. You’re not looking for anything specific. You’re just letting them get their brains going. Challenge observations (by putting it back to the group and/or by letting them observe again, this time for that specific thing) that conflict with each other (or that are obviously not true), but don’t try to push them in any specific direction overall.

The check-x system helped the kids challenge each others’ observations in a non-threatening way. It also allowed me to quickly assess what they noticed.

The entire activity took 10-15 minutes during which kids engaged with each other and the material in a meaningful way. Can’t complain about that. Y’all have a great weekend, I’m off to pick apples in North Georgia.

Labs: Something I Want to Do Better

Whenever we enter the physics lab (really, it’s just the back half of my room so I’m talking metaphorically here), I feel the weight of big-S Science on my shoulders. I want to do it right. But I don’t know really what that means.

For one, I know a little about inquiry and know that I want some of that in my labs. Years of traditional education taught me that science and my own curiosity weren’t similar at all. You went in, followed some complex procedure and verified something you already knew and believed. Unfortunately for me, the verification and “proving” didn’t mean anything because the procedure shrouded all the real discovery in mystery.

For another, dispelling misconceptions seems like the most important work I can undertake as a science teacher. I definitely want some of that in my labs.

I think I’m improving at writing labs but they’re still unsatisfactory. Here’s my emotional laboratory roller coaster that often ends at unsatisfying:

I accept the challenge to write a lab that doesn’t feel like a waste of time and that kids actually learn from.

About the Lens Lab

Below is an optics lab I wrote with a colleague. We’ve already studied mirrors and done a little investigation with converging lenses. Kids know the mirror/lens equation:

My focus is on getting the kids to understand 1) the focal length (F) is a property of a lens independent of where you place an object, 2) when an object is placed at near-infinite distance from the lens, the image distance (di) equals the focal length (F), and 3) that the kids already know of real uses for lenses in different configurations. Do these goals come through in the lab?

I’m pretty happy with the final part (bottom of the last page).

Assume I’m not interested in a complete overhaul to modeling physics. What suggestions do you have to make my lab, or labs in general, better?

Solving Algebraically

New hashtag, folks! #physicsteacherprobz. And entry #1 is the student who solves a problem by substituting values first.

What do my kids do when they encounter this?

A simple pendulum has a period of 2 seconds and length of 1 meter. What is the acceleration due to gravity in this environment?

For the non-physics peeps reading, a simple pendulum has a period (T) given by this equation:

Kids are gonna solve for g like so:

Uploaded with Skitch!

To me, that’s so ugly. Substituting numbers in at the beginning and calculating intermediate answers. Kills me to read tests solved this way.

I prefer my physics students solve equations algebraically before substituting numbers for two reasons. One: compounded rounding errors can blow the result. Two: algebra errors are really hard to spot, making the justification of this answer harder to follow. [Of course, the reason “because your teacher wants it that way” isn’t sufficient. -MHG]

There is long term value is in describing a relationship in terms of any variable, no matter how the relationship was stated when you were introduced. Right? (Right?)

Solving the pendulum equation for requires a student to apply algebraic rules of inverse functions. Maybe the kids aren’t comfortable with this symbol manipulation. Numbers are concrete, so kids like to plug ’em in soon as possible.

In all my time in the math classroom, we never had equations of more than one variable, so I think the kids are stunned when they see that simple pendulum equation.

How do I get the kids to see value in solving an equation algebraically before substituting values? #physicsteacherprobz