PPLUS: Project-based Physics Lab for Undergraduate Students

The short answer is: The aim was to expand and consolidate the P+ as a sustainable alternative to the standard physics lab course.
Long answer: The physics lab course at ETH Zurich is designed to prepare students for practical experimental work over three to four semesters. To do this, they need knowledge of measurement techniques and devices, how to use them correctly and how to interpret and analyse measurement results. In the conventional physics practical course, this is taught through predefined experiments that the students carry out independently. They record and analyse measurement data. However, these ‘recipe book-like’ experiments offer little room for students› own ideas and explorative approaches. In particular, planning their own experiments and dealing with unexpected results are neglected. As the students are provided with an existing setup, they primarily learn how to operate it, but not how to design, optimise and critically evaluate an experimental setup.
In the professional life of a physicist, however, precisely these skills are essential: the translation of physical questions into an experimental setup, the iterative improvement of measurement methods and interdisciplinary collaboration in the development of a suitable setup. In addition, other skills relevant to scientific practice, such as troubleshooting or efficient teamwork, are difficult to teach in traditional courses. Artificially introduced sources of error can address deficits, but often lead to frustration and reduce student motivation.
To address these challenges, the project-based physics lab P+ (Project-based Physics Lab for Undergraduate Students) was developed as an alternative to the existing lab. P+ enables interested students to plan, set up, carry out and analyse their own physics experiments in groups of six under supervision. The time required is the same as for a regular work placement, but students also acquire valuable skills in project planning, exploratory problem solving and critical evaluation of measurement results.
The concept was successfully tested in a pilot project in the spring semester of 2023 with 18 students who were supervised by three assistants (doctoral students or postdocs in D-PHYS). The Innovedum project now aimed to establish the P+ in the D-PHYS curriculum in the long term. In order to meet the high demand, the number of participants was increased to 36 students, with the direct supervision of the groups now being covered by six student assistants (HTAs), who were recruited from the pool of former P+ participants and supervised and accompanied by two experienced assistants. The funding from Innovedum enabled this transition from a pilot project to a sustainable course. The D-PHYS has agreed to cover the recurring costs for the HTAs in the long term, so that P+ will remain a permanent part of the course programme.

After a successful pilot phase in which students were supervised by regular assistants (PhDs, postdocs), the aim was to establish P+ as a permanent, sustainable alternative to the conventional physics lab course.
Even during the pilot phase and in the second round, the demand for P+ far exceeded the available places by a factor of two, despite doubling the capacity. An additional supervision layer was therefore introduced in order to offer P+ on a long-term and sustainable basis: The 36 students were each supervised in groups of six by a student assistant (HTA), and 3 student assistants were each supported by a regular assistant (TA).
In the tutorials, the student assistants continuously accompanied their groups, while the TAs were available as discussion partners or for support when needed. When carrying out the experiments, the assistants were able to use their extensive experience to intervene in a targeted manner and support the groups. The students› final reports were first corrected by the HTAs and then checked and approved by the TAs for quality assurance purposes.
The HTAs were specifically recruited from among P+ graduates. As a result, they not only brought valuable prior knowledge with them, but also a high level of motivation to actively help shape and further develop the P+ due to their connection with the P+.
The collaboration in this new structure proved to be extremely successful, both between the students and the HTAs as well as between the HTAs and the TAs. The evaluation at the end of the semester confirmed that the HTAs played an invaluable role within P+. They formed the bridge between students and lecturers, but because they themselves had recently taken the place of the students, this otherwise large gap in the university context was bridged. In addition, all assistants themselves benefited enormously from their teaching activities by gaining skills and experience that went far beyond the regular subject matter. Group leadership and project planning are just two of the many skills mentioned by the teaching assistants when listing valuable learning experiences.
By introducing this additional supervision layer, we have been able to show that P+ can be designed to be sustainable and future-proof. The comparatively low financial costs are offset by the great learning gain for the student assistants on the one hand and the saving of several regular assistants on the other. The successful realisation of the Innovedum project has made it possible to integrate the P+ into the curriculum as a permanent and sustainable alternative to the traditional physics lab course.

The implementation of the Innovedum project has confirmed that the P+ project-based physics lab efficiently conveys central learning objectives of practical training – objectives that are often not addressed in traditional lab courses. The exceptionally high motivation of the students, which led to enormous learning success, should be emphasised in particular. A quote from the student feedback, which also serves as the title of our publication on the P+ concept, sums this up perfectly: ‘Everything I love about physics.’ This expresses that physics should be experienced and taught in the same way as was possible in P+.
In order to measure learning gains, two self-assessment surveys were conducted before and after the P+, covering 23 different competences. The comparison with students who completed the regular lab course due to limited capacity showed that the learning objectives defined in the P+ were successfully achieved and that the graduates experienced a significantly greater learning gain. However, due to the limited number of participants, no comprehensive quantitative statements are possible.
We were particularly surprised by the intensity of the positive feedback from the HTAs. They benefited enormously from the change in role from students to assistants: many learning objectives were deepened once again, and accompanying the students felt like a refresher course with additional responsibility.
With the introduction of an additional level of supervision by the HTAs, P+ has been successfully transformed into a sustainable, scalable teaching concept. The additional financial outlay is more than compensated for – on the one hand by the considerable additional learning effect of the HTAs, and on the other hand by the reduction in regular assistants, whose costs are often less transparent, but not lower.
A key learning was the importance of effective knowledge transfer between the P+ cohorts. To ensure this in the long term, a wiki platform was set up at the end of the project, supervised by a specially recruited assistant. This platform enables future students to access knowledge that has already been acquired and serves as a publicly accessible resource that creates additional motivation to produce written work of a high standard.
Experience with P+ shows that multi-level support not only deepens students› learning, but also offers assistants great added value. The model can therefore be easily transferred to other subjects and larger student groups.

• Wiki zum PPLUS