P+: Project-based Physics Lab

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The P+ is an alternative to the regular physics lab course, where students can plan, build, perform and evaluate their own physics experiments. Researching one’s own project in a group of six with the same TA turned out to be so motivating for the students that they regularly surpassed themselves. While squeezing natural crystals, shooting water rockets onto HPP and measuring the damping constant of beer foam, the students learned one fundamentally important thing above all: Solving problems in groups is highly efficient and great fun!

Project-based Physics Lab

Regular physics labs at ETH follow a traditional guided-inquiry format. In this setting, a group of two students prepares for an experiment at home by selecting one from a catalogue of available experiments. The students then come to the lab, utilize the existing setup to conduct the experiment, take data, and analyse the results in a scientific report.

In the P+ program, we introduced a modified approach, and allowed the students to find their own physics projects which they could investigate in the lab. Over six two-weeks cycles, the students defined a physics problem, discussed how to approach it and what they could investigate, planned an appropriate experimental setup, and finally carried out the experiment. Due to the explorative nature of such projects, students naturally encountered interdisciplinary thinking, and had to deal with unforeseen difficulties and challenges.

Each group of six students was supervised by one TA (Teaching assistant, either PhD student or PostDoc) who remained the same for the whole semester. Initially, working in a larger group than usual was not easy, but over the course of the semester the students developed skills in group management and project planning. Consequently, by the end of the semester, each group could efficiently organize itself.

(Un)limited possibilities

To ensure that learning goals are achieved, we established a preliminary schedule for planned experiments in the first week of the semester. We made sure that topics from different field of physics were covered, and that the students used various experimental techniques and equipment. Besides that, and by keeping safety regulations in mind, we allowed the students to design their own setups. While we provided some experiment ideas, the primary source of inspiration for the students came from YouTube videos and other online resources.

Technicians had the capacity to construct small items, and there was a budget from which students could buy necessary equipment. Surprisingly, this was a strong motivation for the students to carefully consider what they needed to buy or have built. Granting the students autonomy in designing their setups came hand in hand with responsibility and diligence. The suggestions and guidance by the TAs and lecturers were highly valued by the students, fostering discussions conducted on equal footing.

Student’s feedback

We evaluated the P+ program by asking the students to fill out two surveys: one before the lab sessions and another after they completed the labs. As a reference, we also asked students who participated in the regular physics lab to fill out the same surveys. We can clearly observe that participants of P+ acquire additional skills in fields that cannot be taught in traditional labs, such as troubleshooting a setup or defending chosen approaches in a scientific context. We were overwhelmed by the enthusiasm and dedication the students showed. They were highly motivated to master their own tasks, yet surprisingly, they did not exceed the allocated time for the course.

Students highly valued the P+ program, particularly praising the benefits of working in larger groups, the freedom to design their experiments, and the open discussion culture. Nevertheless, some suggestions were made to refine the P+ program for future students: Occasionally, the experiment felt a bit rushed and the students would appreciate to have more time per experiment. Also, a small workshop where the students could prepare a setup would be appreciated by both students and technical staff, because it would also reduce the workload for the staff. Both alterations will be implemented in the coming semester.

Next steps

The pilot project of P+ took place in FS 2023, involving 18 students and 3 TAs. The exceptionally positive feedback received from both students and TAs motivated us to further expand the P+ program. In addition to the aforementioned adaptations (allowing more time per experiment and incorporating a small workshop for students), our plan is to replace TAs with students’ Teaching Assistants (HTAs). Ideally, these HTAs have enjoyed the P+ during a previous semester, and can therefore support the students with valuable experience. For every 3 HTAs, we intend to have one experienced TA (PhD or PostDoc) who is not directly involved in the groups but supports the HTAs in their supervision, adhering to the motto of «teach the teacher”. By introducing an additional layer of supervision, we expect that the workload will be more evenly distributed, ensuring that the format of P+ is sustainable and scalable.

For me, P+ was an instructive, enriching experience. I feel a lot more confident working in a lab. I leanred to take responsibility, reflect on procedures and work in team.
(Participant of P+)
What are the innovative elements in your project compared to traditional lab courses?
Traditional (physics) lab courses are based on guided or at least structured completion of tasks. The students learn quite some hands-on skills, but usually the outcome of an experiment is clear, and not so much heads-on is required in order to pass the course.
Letting the students decide about their own experiments, their goals and the ways how to achieve them requires many additional skills: project planning, critical (self-)assessment, ways to deal with problems and failures are only some of them. Many skills acquired in the P+ program are transferrable to other situations which students will encounter later in their career.
What effect did these innovative elements have on student learning?
In preliminary evaluation of feedback, we clearly see that the students rate their gained competencies in problem-solving, planning and scientific communication significantly higher than the students which completed the regular lab course:
- The presentations of their experiment trained the students to outline and motivate a project in a concise way. We observed a strong increase in their skills throughout the semester.
- Having open inquiry experiments means that there is no clear way how to achieve goals. Initially, the students struggled to outline a clear road map for their experiments. Towards the end of the semester, the students could present a structured plan for the experiment, including intermediate milestones and estimates for results.
- The trouble shooting skills which the students developed allowed them to spot potential mistakes and difficulties earlier on. This led to less (spontaneous) work for the supervising TAs and the technical team.
How did you ensure continuous feedback to the students?
The close contact between students and supervisor is a key ingredient for this teaching format: With two meetings per week dedicated to experiment planning, one fully supervised afternoon with the TA, and iterative report writing, we establish a continuous feedback loop for monitoring students' learning progress. Furthermore, the consistency of having the same TA supervising a group ensures ongoing monitoring of the progress throughout the semester, contrasting with the traditional lab supervision model where a different TA is assigned to each experiment, resulting in a mere snapshot of the students' proficiency level.
Which elements of P+ would you recommend to other lecturers in charge of projects or lab courses?
Although we know that such a close supervision with the ratio 6:1 is not always possible, we observe that this interaction is most beneficial for the students. Having one TA which is almost considered as part of the group builds a relationship of trust, in which the feedback can be given and received in an authentic and efficient way.
Furthermore, because the students solve open inquiry experiments, they are naturally thinking a lot about it. There is no danger that they learn “hands-on but not heads-on”, because there is no manual which one can blindly follow.
Last but not least, the motivation achieved by self-determination and a certain degree of freedom is also a heavily contributing factor for the successful pilot project of P+.
I express my genuine enjoyment and positive experience as a participant of P+. I highly recommend the program to others who are seeking a valuable learning and growth opportunity.
(Participant of P+)

Course Description

Physikpraktikum P2
Project-based Physics Lab for Undergraduate Students
Students can define, plan and build their own physics experiment, in contrast to the traditional guided-inquiry experiments offered in the regular physics lab course
Bachelor-Level (4th semester)
Lab class
Lab class
Teaching Power:
1 TA / HTA per 6 students
pass / fail course

ETH Competence Framework