Sunday, January 24, 2010

The End of Semester Project

Ideas for an end-of-semester project

Our second quarter schedule in the Regular Physics course at Glenbrook South includes two weeks after winter break, plus an additional week in January for final exams. For the second year in a row, my colleagues and I have used the last two weeks of the quarter in January for an extensive, lab-based student project with our Physics 163 (middle-level) students. Students are given an open-ended challenge. They must design and run one or more lab investigations that link to several topics we have learned throughout the semester. Students are expected to select complex, measureable lab goals and use a variety of lab equipment in their investigations. Specific directions and the student rubric can be found here. The “pros” of this project are numerous: student interest is peaked by the opportunities for student choice, students connect topics they have learned throughout the quarter, students do thoughtful analysis, students get a taste of what real scientists do, students feel genuine pride at accomplishing a challenging task, and so on. Potential cons include the amount of class time that must be dedicated to the project, the need for laboratory equipment, and the handful of projects that inevitably don’t meet the teacher’s high expectations. I will discuss implementation of the project, state the pros and cons of the project, share a few case studies, and discuss ideas for improving the project and minimizing some of the cons.

Timeline for the project

Prior to introduction: The teachers selected a list of equipment they would provide for students. We then set up the back of the classroom like a “buffet” of equipment. Students would be expected to borrow equipment during the class periods and then return everything to clearly labeled bins in the back. The exceptions were high-theft-risk items such as cameras and electronic balances; students checked these out from the teacher when needed. Teachers also reflected on their desires for the lab and updated the directions (found here) as necessary. The project was scheduled for the last two weeks of second semester. Students had already studied motion in 1-D, forces, 2-D motion and forces, projectiles, momentum, and energy. It was key to do this project at the end of the semester so that students had a range of physics knowledge from which to draw.

The introduction: The project was scheduled for seven class days over a two-week period. On the first day of the project, I handed out the directions and rubric and explained the overall goal. Students were told not to worry if their initial reaction was to feel stumped. Students were encouraged to look back over their lab journal and think about the labs we had done throughout the semester. I also suggested that kids should look at the equipment provided in the back of the classroom. I told students that this was not the only equipment they could use and that they were welcome to ask for additional equipment as needed. On this day and several times throughout the project, students asked for an exact number of labs or topics required. In the past, I told them a minimum number of labs required. This year, I was careful to not give a numerical answer to that question. Rather, I reminded students that their goal was to create a lab (or labs) that is complex, not a repeat of something we’ve already done, and that spans several physics topics. I reinforced that they could do this in one very large and complex lab or with several smaller labs. Students were told that they could pick a partner but that they’d each need to record data and produce their own lab write-up (goal, procedure, data, calculations, and conclusion).

The first few days: The first few days involved a lot of student brainstorming as they tried to pick appropriate goals. When students were stumped, I asked them if they had interests outside of class that they wanted to link to physics. For example, one group was interested in modeling how an airplane takes off from an aircraft carrier. Their project used motion and force sensors to determine the effect of air resistance on a small vehicle. They also linked their goal to work and kinematics. Another group was interested in golf balls. They did a video analysis of their golf swing and also made distance measurements; they then used their data to link work and energy to projectiles and air resistance. I found that I did a lot of listening and suggesting at the beginning of the project. I tried not to squash an excited student’s idea even if it initially seemed too simple. Rather, I encouraged the student to start on that lab and then think about what additional topics they could work into the lab as they did it; I also offered ideas about how they could bring in additional physics topics to their project.

The middle: The middle of the project involved lots of discussions about experimental methods. Frequently, I ran to the prep room behind my classroom to get additional materials. A student modeling collisions with an air bag in a car wanted Ziploc bags; a student connecting energy to projectiles and work done by friction wanted hot wheels tracks and cars; a student launching a projectile into a cup to study projectiles, collisions, and energy wanted cups; students studying friction wanted a variety surfaces made of different materials; students projecting marbles into cars wanted cotton balls. The list goes on. I was lucky to have lots of materials on hand; at the same time, teachers at schools with a smaller variety of materials could simply have students bring in any additional items they wanted to use. I was surprised by how many students chose to use video cameras and analyze the video using the LoggerPro Vernier software. We didn’t use the cameras to do video analysis more than about once a month during the semester. However, students were very comfortable with the cameras. Video footage (or should I say “bitage”—no need to measure feet of tape any more) is a huge part of students’ world and they bring a lot of technical expertise to the table. A large percentage of students also used Vernier probeware such as motion sensors or force probes during their project.

The results: As I am writing this article, I am at the front of the classroom and my students are taking their final exam. In an hour, when the exam ends, they will turn in their journals which include their final project. A few turned in their projects already and I have graded those. The results of student learning will vary from student-to-student. Some students will have learned more about analyzing videos while others may have learned more about analyzing errors in the lab. However, I feel that all students benefited from experiencing what “real science” looks like. The students were invested and excited about their project and did think deeply about the connections between the physics topics. The process itself was valuable. Admittedly, the students did not all learn the same physics content during the project. There is a constant pull between wanting to give the students time to investigate and making sure to cover enough topics. In December, I was wondering if I really wanted to do this project again. I was thinking about how we could spend the two weeks doing another chapter in the book instead. I am so glad I did the project again and remembered how much I value it. Several case studies below show examples of student experimentation. The case studies also illustrate how varied the projects can be. Teachers should be flexible and reasonably comfortable with physics and experimentation so that they can guide their students.

Case Studies

Case study #1:

The image to the right shows a stuffed pig swinging like a pendulum from a rope attached to the classroom ceiling. Why? Because this group was (a) obsessed with the stuffed pig, and (b) attemping to have the pig safely land on the foam on the floor. A razor cut the string when the pig was in the lowest position of its arc. They did a vector analysis of the tension, used energy to predict the velocity at the bottom, and then used projectile equations to determine where the foam should be placed. This was only part of their analysis. Another group did something similar, but they had the pendulum hit a stationary object that then became a projectile. This meant that they were also doing a momentum collision analysis along with energy and projectiles.

Case study #2:
The group with the two photos here set up a projectile launcher at an angle. They found the initial velocity of the launcher and determined where to set a tube (incined plane) to catch the marble. At the bottom of the tube, there was a cart with a cup on it as shown in the picture on the right. They did a work-energy analysis as the marble slowed to a stop in the cart.

Case study #3:
The girl in the movie still-shot at the right is an avid horse-rider. Her goal was to learn about the power involved in a horse’s jump and also to analyze the motion of the horse in the air and see how much of an effect air resistance had on the horse’s motion. She relied on the video-analysis feature of the Vernier software program Logger Pro. As this image shows, I allowed students to check out cameras if they wanted to do a real-world experiment that couldn’t be modeled in the classroom. Students checked out cameras to help them analyze golfing, sledding, driving, and the like.

Ideas for extending the project:
In reflecting on the past two weeks, I feel that there were two big things missing from this project. I would have liked the students to have received written (as opposed to only oral) feedback from me during the project. I would have also liked students to share their projects with the rest of the class. Both of these were accomplished by a co-worker of mine. He had the students present their projects not in a journal but on their class Wiki. Students could see each others’ projects, and my co-worker commented (in red text, of course) on their writing as the project went on.

This month's article is contributed by Debbie Berlin. Debbie is a graduate of Northwestern University in Evanston, Illinois. She has been a high school physics teacher for 11 years. Debbie currently teaches Regular Physics and Honors Physics at Glenbrook South High School in Glenview, IL, where she has taught since 2004.  

1 comment:

  1. nice blog !! i was looking for blogs related of Physics lab equipment . then i found this blog, this is really nice and interested to read. thanks to author for sharing this type of information.


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