Circuits and Charges: A Physics Active Exam

This fall, I will be starting my 2nd year at a really cool progressive day school in NYC. The science curriculum is in the process of evolving, but the current program has 9th and 10th graders rotating twice through physics, chemistry, and biology (in any order) on a trimester system. This past year, I taught the 10th grade physics one-trimester course and the topics were on electricity & magnetism (for students who hadn’t yet seen any mechanics). The 10-week class offered a lot of interesting challenges—teaching students for only 10 weeks (building micro class cultures and starting over again and again), teaching these topics as a stand-alone set, and figuring out how to fit into the culture of the department and the school. There is a lot to talk about, but I will focus in this post on how I interacted with the end-of-trimester final assessments through the lens of progressive education.

Finals at a Progressive School

There has been some talk this year about how we use our end-of-trimester time. Does it make sense to give up about three weeks of the year for these final assessments? Are teachers using that time for exams? Many have chosen to do papers, projects, or presentations instead—could we continue classes for those extra weeks instead of having exam days? What should final exams/assessments look like at a progressive school?

In my case, I was teaching courses this year that were very different from what I had taught in the past. In my yearlong physics classes of old, I think I have been able to create experiences with written final exams that were significant for students. I don’t think the same sort of experience is possible in a one-trimester course because of how little time there is to build the culture, cultivate investment in the class by the students, and how little content they have to work with—it is tough to get them doing deep synthesis work when they’ve really only encountered two or three topics.

As I got to the end of my first trimester, students started asking what the final would be. They told me about the variety of experiences they had had in other classes and what they thought would be the best way to show their understanding. And most of all, they (or most of them) were pretty adamant about not wanting a 2 hour test. Fair enough! So I took everything they said to heart and thought about how to create an experience during our 2 hour slot that would feel authentic. I also wanted it to both give me a chance to learn about what they knew and give them a chance to see and feel what they had learned. I wanted them to leave the class feeling a little more empowered in the way they interact with the physical world. (No big deal.)

An Active Exam

Thinking about this problem, I realized that I wanted to final assessment to be in the same spirit as the class—just with an individual focus (since I needed to assess them in a summative way) instead of a group focus (since the process of constructing knowledge and learning is a collaborative and social one). What I came up with was a sort of practicum-based assessment in multiple parts.

The Physics 10 course was a little different in each trimester (how could it not be with different groups of students, different personalities, and my own process of iterating through the development of the class?). In each class, though, the main two topics that we studied were electrostatics and simple circuits, so the exam was based around activities in those areas.

Since I wanted students to be moving around the classroom, using equipment, and doing different activities, I had to be thoughtful about how to make that run well. I spaced out stations around the room, and I created several different tasks for each category. I randomly paired tasks together (one from each category) and put them in envelopes. I gave envelopes to students when they entered the room, and I had no idea which tasks/questions they would each be assigned.

Physics10ExamEnvelopes

The random tasks meant that students could work closely together in the room on different questions. I could work with students, check their answers (part of one of the circuit tasks—see below), etc without having to put effort into monitoring any conversations or glances at other papers. That helped make the atmosphere of the exam even more laid back and class-like, which I thought was a plus.

Charges

For the charges task, students found a sheet of paper in their envelope—everyone had the same instructions followed by one of about eight to ten different questions.

ChargesTaskInstructions

Some samples of the questions they might have encountered:

  • Describe the difference between charged objects and magnets and decide on an experiment that can be done to illustrate those differences.

    Describe specifically and carefully (using words, pictures, charge diagrams) how you can do this and why it will work.

  • Can a conductor be charged? If so, how would you charge a conductor? If not, why not?

    Describe specifically and carefully (using words, pictures, charge diagrams) how you can do this and why it will work.

  • You have a conducting sphere. Without touching the sphere with anything but your hand, figure out how to give it a net positive charge. You may use any materials you like, but only your hand can touch the sphere.

    Describe specifically and carefully (using words, pictures, charge diagrams) how you can do this and why it will work.

In the desk-filled part of the physics lab, I put the desks into tables (a normal setup of our classroom anyway), and I put out lots of supplies that they had used during the trimester (sticky tape, electroscopes, fur, various rods, foil, magnets, plastic wrap, etc) and that they might want to use as they decided how to answer their question.

ChargesSetupCollage

If the equipment they wanted was in use, they could pop over to one of the circuits stations and work on another part of their exam while they waited. Their set of tasks could be done in any order.

Circuits: Building

The circuits part of the exam was actually a combo of two different tasks (again randomly paired together). At one lab bench, I put out four sets of circuit components (to make four stations that could be used at the same time).

CircuitBuildingStation

Everyone had the same instructions on the top of their circuit tasks paper, but one of about five or six different circuits to build.

CircuitTaskInstructions

Here is a sample of some of the questions they might have encountered:

  • Using the parts provided in the classroom, build a circuit that has three bulbs and two switches. Two and only two of the bulbs should be in parallel. Call me over to see the circuit only when it is complete.
  • Using the parts provided in the classroom, build a circuit that has three bulbs and two switches. When both switches are open, all bulbs should be off. When both switches are closed, only one bulb should be off. Call me over to see the circuit only when it is complete.
  • Using the parts provided in the classroom, build a circuit that has two bulbs and one switch. When the switch is open, one bulb should be on and the other off. When the switch is closed, both bulbs should be on. Call me over to see the circuit only when it is complete.

StudentsBuildingCircuits

When they called me over, I would check the circuit and make a mark on their paper when it was correct. If it wasn’t correct, I didn’t give them any specifics—I just told them to keep working. Every student was able to complete this task correctly, even if they needed a couple of tries to work it out, so everyone left the exam knowing they could feel good, at the very, very least, about that part of the test. Awesome!

Circuits: Puzzle Box

The bottom of the circuit task page assigned them one of three or four different puzzle box circuits to inspect.

PuzzleBoxCircuitTask

I was inspired by something in the PUM materials that I had been stealing from a bit this year, and I spent some time creating these circuits where the wires were hidden. I didn’t have all of the materials that might have been ideal, so I scavenged around the lab and school (and the wonderful Amber at the front desk walked around and found me some perfect empty boxes from the nurse’s office) and used whatever I could find. And, actually, because of the messiness of it all, even if they tried to figure it out by looking in the boxes, it would have been basically impossible. Surprisingly, these boxes ended up being really sturdy and reliable.

PuzzleBoxCircuitCollage

This task was definitely the part of the exam that students talked about afterward and told the next group of students to anticipate. It was also related to some activities that we had done in class, but asked in a different enough way that it was really fun for me and for them.

StudentsSolvingPuzzleBoxes

Misc Exam Tidbits

Each trimester had a little different flavor to their experience, so I’m going to briefly document those pieces here.

In the first trimester, there was a third part of the exam. One at a time, students went out into the hallway to do a brief interview with me. I gave them one of a set of about 8 or 10 different problems (all of them were TIPERs tasks) and had them talk me through their thinking. This setup meant that I was actually out of the room for almost the entire exam, and I was really lucky to have a couple of colleagues step up and come to school when they didn’t have to be there so that I could have an adult in the room with the students. I really appreciate the freedom that I have at my school to be experimental and try wacky things like this exam, and I especially appreciate the extra support to make it happen. (So big thank-yous go out to Chris and Alan (and Amber!) for making this experiment possible.)

In the second trimester, we had a bit more class time (the year wasn’t divided completely evenly), and we started some work on magnetism. I gave them an optional extra task in their envelopes—a couple of magnetism TIPERs questions, including one that involved Newton’s 3rd Law (something that we had spent some time thinking about during electrostatics), and I was really impressed by the transfer and thinking that they showed there. The reasoning they gave for their answers was excellent and referenced activities or problems from earlier in the trimester. Some of them even tried to use the electrostatics materials (including magnets) to test their ideas.

The first circuits task evolved from T1 to T2—in the first trimester, I only asked them to draw a schematic for a circuit that I had already built and left laid out for them on the bench. In the second and third trimesters, I felt ready to ask them to do a little more, and I moved to the task I described above.

Near the end of the second trimester, I made a survey for students asking for some feedback and also asking for what kind of final assessment they wanted—they largely wanted something active and had heard the first trimester final was fun, so they asked for something similar (and of course I obliged).

Next Year and the Future of my Physics Exams

Next year, I will be teaching both the 9th and 10th grade one-trimester physics courses. Since I will have the opportunity to design the two-year sequence, I am probably going to change the topics quite a lot. So this particular exam is being retired (for now, at least). The overall reception of this assessment was really positive from the students, and I was happy with the way it ended my class. I’m excited to see what my students inspire me to create for them next year—and to see what they will create in response.

7 thoughts on “Circuits and Charges: A Physics Active Exam

  1. I love this “exam.” I tried to do things like this when my school switched from semester exams to “quarterly assessments” but I never made such a complete transition. I also generally had more topics to assess. I hope to see you at AAPT!

  2. This was so interesting to read. I really enjoy finding out how other people do things in a meaningful way. Thanks for sharing. I wish I could sit down with you for an hour and ask you all sorts of questions!

    I have been trying out lab practicum and transfer tasks (sometimes similar to your Goal Less problems) for end of unit/term assessments, they generally are received well. I also see that kids really need a base level of understanding to get anything done on them. They are a bit binary in that sense. But they do a good job of assessing what we really want students to take away from the course or unit.

    For younger grades I have many students that really don’t engage in a meaningful way, they would totally bomb the type of assessment that you have used. That’s where building a class culture is so important. 15 year old boys can be tough eggs to crack though.

    I really look forward to hearing about what you plan for next year.

    1. Thanks! And I’d love to sit down for an hour and talk about teaching (obviously one of my favorite things). Hopefully we get the chance some time! 🙂

      I agree—15 year olds are wonderful, frustrating, awesome challenges. I should say that this exam wasn’t a huge influence on their grade for the trimester, and every other assessment had been retake-able (with a flavor of SBG that I still need to write up here), so the stakes felt pretty low, I think. And students who had already been through the exam assured the current group that it was fun and that they shouldn’t be stressed about it, so that helped a lot, too. And yes, class culture is everything. (That was one of my biggest challenges this year in the short classes—I did a much better job in T2 and T3 than in T1.)

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