Supporting physics teaching with research-based resources

Q: I want to give my students something to work on in groups, but what should they work on? I know that researchers have created many physics activities, but I don’t know what I’m looking for. What does a good activity look like? OR, I’m really excited about inventing my own labs or worksheets to give students, but I don’t know how to design an activity.

A: I would recommend, first, looking at PhysPort’s Teaching Methods page to see if you can find something that fits your needs. When you can’t find an appropriate pre-made activity, it’s good to know how to design your own. In either case, you should be aware of a few strategies that have been used to design many successful physics activities. The design strategies below were selected because they are present in most research-based activities.

Strategy #1: Guide students to figure things out for themselves: an activity shouldn’t be a “cookbook”

A “cookbook” lab is one that tells students exactly what to do. They may be told what the conclusion is supposed to be, what equipment to use at what time, what measurements to make, and what equations and numbers to use. The lab may become little more than an exercise in following directions and plugging numbers into equations – not that exciting for the students, and nothing like research in a real physics laboratory. Students will probably “succeed” at a cookbook lab. But will they learn anything? The opposite of a cookbook lab is an “inquiry” lab, where students have to figure more things out for themselves. Depending on how daring you feel, you can ask students to figure out the conclusion, the experimental procedures, the equipment they will need, or even the problem they will investigate. (Buck, Bretz, & Towns, 2008) Some labs that ask students to design the laboratory procedure include ISLE and Scientific Community Labs.

Strategy #2: Ask students to explain themselves in words, not (just) numbers.

Numbers and equations are very important in physics, so it’s natural to want to ask students to work with numbers. But the fact is that procedural mathematics is the easy part of physics for many students. The hard part is not crunching numbers, but knowing which numbers to crunch. To help students figure out when it’s right to use a particular equation, take a step back and help them to talk about physics scenarios in words. You could try questions like:

• “Why?”
• “Explain your reasoning.”
• “How does situation X compare with situation Y?”
• “What have you learned from this activity?”

Beyond words and numbers, you can ask students to explain themselves by drawing graphs, free-body diagrams, or pictures. They could also answer multiple choice questions or rank items from smallest to largest. (Von Korff et al. 2015) The Tasks Inspired by Physics Education Research (TIPERs), Ranking Tasks, and Tutorials in Introductory Physics exemplify this strategy, as do many other activities.

Strategy #3: Figure out what conceptual questions are challenging for students, and have students come back to them. Some physics questions are especially tricky for students; it’s important to notice these questions and give them special attention.

Example of a tricky question: force on a baseball: Suppose a baseball player named Amy is throwing a baseball. Try asking your students whether Amy exerts more force on the ball, or the ball exerts more force on Amy? Many students will say that Amy exerts more force, or even that the baseball exerts no force. After all, Amy can exert force with her muscles, but the baseball is not alive and has no muscles. What does it have to push with? Also, Amy is bigger than the baseball, so she must be able to exert more force. And Amy’s velocity does not visibly change, while the ball’s velocity changes dramatically.

How to “come back” to a tricky question. When a question looks simple but has the potential to confuse students, it’s useful to come back to it. For example, students could answer the question about Amy individually, then immediately return to the same question and discuss it as a group. Here are a few strategies for “coming back” to a challenging question.

1. Checking for consistency. After students answer an initial question, ask a related question that they can use to “check their answer.” For example, what if Amy is standing on a skateboard when she throws the ball? Does the skateboard move? And, does it take a bigger force to move Amy-on-the-skateboard or to move the baseball? If students’ answer to this question is inconsistent with their previous answer, it may get them talking.
2. Statements by fictitious students. After your students answer a question on their own, they read statements made by one or more fictitious students that present some different perspectives on the same question.   (“Tyler says, ‘Amy is bigger than the baseball, so she must exert more force.’”) It’s good for your students to consider arguments they may not have thought of; but even if they have thought of these arguments, they may not have discussed them to everyone’s satisfaction.
3. Have the students make a prediction about what will happen when they perform an experiment. Then, have them answer the same question experimentally.
4. Checking with the instructor. Write into the activity that the students should call the instructor over to their table and discuss their answers. Hopefully, the instructor is not going to tell them whether they’re right or wrong, but will ask helpful questions.
5. Work individually / work as a group. Students think about the tricky question individually, then discuss the same question with their group.
6. Visiting other groups. Students think about the tricky question as a group, then some students visit other tables to discuss the same question with other groups. (A few students must stay at their original table to receive guests who are visiting from other tables.)
7. Explaining the answer. Sometimes, you just have to tell students the answer. But when you do, it’s best to tell the answer after students have genuinely struggled with the problem on their own.

Why come back to a problem? One reason is for the students to check their answer. Or, students already found the right answer, but you want them to learn different ways of coming to the same answer. Perhaps they got the right answer but they didn’t come up with a good reason for it. Finally, thinking of alternative answers could force students to defend their ideas and come up with reasons. (Von Korff et al. 2016)

Although many activities make use of strategy #3, one that does so very frequently is the Open Source Tutorials.

Going beyond these suggestions: The best way to learn to design physics activities is to study activities that already exist and try to understand how they are put together. Keep the above design strategies in mind, and read some tutorials and labs to see how these strategies are implemented.

A few other resources include:

• PhET’s Approach to Guided Inquiry
• Developing Conceptual Exercises, by David Maloney
• Open Source Tutorials instructor guides
• The introduction section in RealTime Physics
• L. B. Buck, S. L. Bretz, and M. H. Towns (2008), “Characterizing the Level of Inquiry in the Undergraduate Laboratory,” Journal of College Science Teaching, 38(1), 52-58.
• J. S. Von Korff, A. B. Barooni, H. Pamplin, and J. J. Chini (2016), The "revisiting" strategy in physics tutorials, Proceedings of the 2015 Physics Education Research Conference.
• J. S. Von Korff, C. Zhan, B. Vaishnav, J. J. Chini, A. Warneke, and O. Sengul (2015), The Use of Representations in Evidence-Based and Non-Evidence-Based Physics Activities, Proceedings of the 2015 Physics Education Research Conference.
• PhysPort's Recommendation on Where can I find good activities for small group discussions?

Image ©Brian Thoms – Georgia State University CCBY