Jan 30, 2012

Active Physics and Inquiry

4 comments
An independent school in New York City provides an excellent example of a successful application of the Active Physics curriculum, but aspects of Modeling Instruction could have potential to make the course even more dynamic.

Active Physics is a project-based curriculum with a conceptual focus, designed to be used with ninth graders. Active Physics groups concepts by themes, such as "Communication," "Sports," or "Home," in an attempt to make the physics more relevant to students' daily life. The work done in each unit culminates in a "Chapter Challenge," where students must apply their knowledge to solve a real-life problem. One independent school in New York City has been using the Active Physics curriculum since 1994 as the foundation of a physics course for all ninth graders. When I visited this school, students were studying the efficiency of various methods of heating water, and were just about to begin the "Chapter Challenge" of selecting appliances to meet the basic needs of an average family, capable of being powered by wind-generator with an output of only 2400W.

When class began, students were seated in lab groups, discussing a question from their textbook: "Are high-efficiency appliance worth the added cost?" Students' responses reflected a common misconception - conflating the efficiency of an appliance with an assessment of its overall quality: "Well, yeah they're worth it... they're better." "They're more durable, work faster, and just work better in general." When students were asked to present the results of their discussion, only one group in three appreciated the more subtle implications of the concept of efficiency, stating, "A higher efficiency appliance will make up for its cost with less power used over time," but even this group was confused by the difference between the terms "power" and "energy." The stage was set for an inquiry-based activity to root out the would root out these misconceptions and lead students to a more sophisticated understanding of the concepts of energy, power, and efficiency.

The lab activity for the day consisted of heating up a beaker of water on a hotplate. The procedure steps outlined in their textbook were summarized on a projector: "Measure: 150mL of water, initial and final temp of water, measure time appliance is on (increase temperature by 20˚C)." After a brief discussion of how to use the equipment, students got to work carrying out these steps. They made a few potentially problematic procedural choices along the way (measuring water volume with a beaker rather than a graduated cylinder, plugging in the hotplate before starting their stopwatch, resting the thermometer against the bottom of the beaker, for example), but the teacher caught most of these and gave suggestions for improvements when he felt it was necessary to do so. In class discussion, students struggled with how to use the values they'd measured to make the required calculation of efficiency, but the teacher coached them through the process (partly by referring them to a similar activity done a few days earlier with immersion heaters):

Teacher: "Who remembers how we calculate the thermal energy gained by the water?"

Student: "Was that the thing that was 4.18...?"

Teacher: "Yes, we need the specific heat of water. Anything else?"

Over the course of the discussion, each group eventually arrived at calculations that basically agreed with one another, confirming an efficiency of about 10%.

While watching students carry out this activity and discuss the correct method for calculating efficiency, I tried to imagine what the same basic procedure would look like using a whiteboarding approach. Students might start the lab by brainstorming steps they'd take to to collect whatever data they felt were relevant to a calculation of efficiency, then writing these steps on a whiteboard and presenting them to the class for discussion. Once students had carried out these steps with their lab group, they could attempt a calculation of efficiency (again, on a whiteboard), and discuss as a class whether the calculations they'd made were relevant to the central question of the efficiency of appliances. Different groups could even use different methods of heating the water: an immersion heater, a hotplate, a microwave...

I emailed a prominent advocate of Modeling Instruction to ask about crossover between Active Physics and Modeling Instruction, and she told me that "Active Physics and Modeling Instruction don't go well together." Modeling Instruction is about developing basic models for the most fundamental interactions in physics, whereas the projects in Active Physics tend to highlight more complex applications of these concepts: efficiency of electric appliances, acoustic properties of instruments (watch your ears...), how to build a DC motor or generator, etc. Both of these approaches have merit, and it seems to me that there's a lot to be gained in exposing students to aspects of both. That is, a whiteboarding approach might have avoided the more "cookie-cutter" aspects of this particular lab activity on heating water (and probably brought misconceptions to the forefront more effectively), and a project-based "Chapter Challenge" in a Modeling course might give students a better appreciation for how even the simplest models they develop can be applied to their daily life.

In my observations, I've noticed a trend among teachers of Physics First: in the absence of a single universally-accepted ninth grade physics curriculum, teachers tend to pick and choose aspects of various programs that appeal to them. This dynamism is healthy and exciting, but there is something particularly thrilling about the momentum that has been building around Modeling Instruction. A lot of aspects of Modeling just feel like the right way to teach physics: whiteboarding, student-designed experiments, modeling phenomena with multiple representations, and it's tremendous to see the Physics First movement marching forward hand-in-hand with Modeling Instruction. Still, we'd be wise to keep in mind the potential benefits of a diversity of approaches and try to maintain some of the freedom and flexibility that characterizes so many ninth grade physics classrooms.






4 Responses so far

  1. BioGeek says:

    I am simply curious how this works with low socioeconomical students with various levels of metacognitive and science thinking skills. I've looked over the book/curriculum and found few points in which I could teach how to organize complex information so that it could be understood. Further, I found that unless you understand very high level physics, this curriculum is very cookbook style teaching. First do then, then do this, etc. I saw very little room to differentiate between various students and to actually teach to students. Rather, I saw that as an instructor you are teaching to the book.

    Philosophically, a book is meant as a supplement to students learning new information and learning metacognitive skills. The teacher is there to ensure students are thinking about the information and making it applicable to the real world. This allows the teacher to teach to the students. I am not so certain that a book should be a curriculum; one size does not fit all.

    Any thoughts from those who have taught in lower end schools? If I have to teach this soon, I want to know if it has any merits or if the textbook sales people are simply amazing at their jobs.

  2. k. wong says:

    Hi, I am a 9th grade physics teacher in Massachusetts. I learned physics using Modeling, but our district uses Active Physics.

    I personally do not use Active Physics, because I found it too focused on ideas that were not aligned to the MA frameworks. Also, I teach students with learning disabilities, and the many directions in the Active Physics activities left them confused and took away from their learning. I have heard from other teachers in district that this is common for our student population (low socioeconomic). The teachers I know in our district do not follow the curriculum at all.

    I would love to use the Modeling method as I learned it, but because of low math skills, I find myself doing exactly what you said - choosing different aspects of programs that appeal to me, and then creating everything else myself.

    I'd be interested in a way to adapt Modeling for students who are not fully able to grasp mathematical models. My students are still learning algebra when they get to me - and do not reach linear equations until halfway through the year.

  3. JK says:

    Some teachers have created collections of curriculum materials meant for use with Modeling at the ninth grade level, and even for use with students who haven't yet developed the algebra skills to use mathematical models, but these are not well-publicized even within the Modeling community.

    One approach I've seen is to teach circuits using the CASTLE curriculum in the Fall, so that students have taken more math when they get to the mechanics portion. One Modeling-based curriculum for ninth grade starts with energy using bar charts, and this approach could delay the algebra intensive material even further.

    The bottom line, though, is that there is work yet to be done developing resources that are useful for applying a Modeling approach to a wider range of student populations, especially to classes of younger students.

  4. Unknown says:

    I teach a course at a Title I school with a large population of low socioeconomic students that are largely EL and LTELs and we use the Active Physics book. It's a terrible book. It throws in complex concepts like metric conversions and sigfigs in the middle of chapter sections rather than having a chapter solely devoted to measurement and calculation. Also, the expected math level of the book far exceeds the math level of my students. The other problem is in order to "teach to the book" the expectation is that students are conducting long-term learning through PBL-style assessments. The compounded problem on this is that many of the below-grade level students that I am teaching this class to have very short memories and, having already tried implementing a form of the chapter assessment which requires a synthesis of knowledge over the course of a 6-7 week unit (the chapters in the book are way too long), I can tell you from experience that lower grade level students learn nothing from this style. It's too long and drawn out for them, too confusing and they don't realize what they are supposed to get out of it.

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