Author: Brokk Toggerson

Perceptions of interdisciplinary critical thinking among biology and physics undergraduates – Review and thoughts

This is a collection of my thoughts from reading:

A. B. Heim, G. Lawrence, R. Agarwal, M. K. Smith, and N. G. Holmes, Perceptions of interdisciplinary critical thinking among biology and physics undergraduates, Phys. Rev. Phys. Educ. Res. 21, 010138 (2025).

The paper is available on the PaperCast at https://open.spotify.com/episode/394yVw46zKSA8gPYLKLaGh?si=7bb3c2173d9545aa

Structure

This post is a series of thoughts on different topics that arose as I read the paper.

Tasks as the basis of research as well as curricular design and sharing

Listening to this paper on interdisciplinary curricular design, one justification they mention for focusing on learning tasks is that tasks are a manageable level for curricular design research. Tasks are simpler than entire courses, and once designed, they can be sequenced into a full course. An additional argument is that approaching a course holistically is simply too complex. While I agree that designing a course by first defining overarching goals and objectives, then breaking those down by unit, and only then developing tasks to meet the established goals, is more complex, I believe it produces a much stronger result. My initial experience designing 131 is an example wherein I designed tasks first and then strung them together did not produce an effective course. Thus, while I recognize the value of research on tasks and understand why they serve as a convenient focal point for curricular design research, I struggle with the idea that tasks should be the starting point. This perspective connects with ideas I’ve been developing for my new graduate TA training system. Graduate TAs often focus on designing lectures and other tasks, but I want to encourage a more holistic perspective—thinking critically about course goals and objectives first. In summary, while I agree that tasks are a critical part of curricular design and a convenient unit of research, I do not believe they are an appropriate starting point. That approach feels backward to me. It’s like designing the perfect brick before knowing what you’re going to build. If you’re building a house, that brick might be useful. But if you’re building a boat, that perfect brick may not help—and trying to use it could result in a boat made of bricks, which is ineffective at best.

Physics education, especially for biology students and even engineers, is at a point where curriculum reconsideration may not be absolutely necessary, but is certainly warranted. We need to ask: what are we teaching, and why? This line of thinking is influenced by the Hake paper1, which emphasizes that active learning is where learning happens. However, active learning takes time. This means that designing a course requires hard decisions: what do you teach, and—more importantly—what do you drop? I would encourage others, as Redish2 does in his reconsideration of introductory physics for biologists, to start by digging into what you want students to learn and why—then move on to the tasks.

The “Earthworm Problem” as a Level-2 Problem

This is referring to

Alice Churukian, David Smith, Colin Wallace, Duane Deardorff, Daniel Young, and Laurie McNeil, Living Physics Portal: PALS Breathing Worms, https://www.livingphysicsportal.org/details/d7a0eea7-e6a5-4fb9-a644-c276ee0968bf.

Later in the same paper, they discuss the Nexus Physics curriculum’s well-known earthworm problem. This involves comparing oxygen absorption through the skin with oxygen usage in the body—a scaling law problem. Surface area scales with R², and volume with R³. For cylinders, surface area scales linearly with radius, and volume (or cross-sectional area) scales with R². This relationship is relevant here.

While the problem is solid in concept, I still find it somewhat lacking. Perhaps not inauthentic, but not as engaging as it could be. The main issue is that students are told exactly what to do: create this equation, graph that one, identify where the lines intersect. While this applies physics problem-solving techniques to a biological context—which the paper classifies as “level two”—I don’t like that the path is laid out so explicitly.

In my IPLS course, I want students to figure out how to approach problems. They may need some guidance, but ultimately, I want them to be able to look at a biological or chemical situation and apply physics tools independently. The goal is for them to encounter something in a biology or chemistry course and think, “I’ve seen something like this before in physics. I know how to use physics to better understand this phenomenon.”

Importantly, I want them to apply this reasoning to new contexts—not just replicate what we’ve done in class. That’s why my exams use novel scenarios. If they can look at something like bird vs. bumblebee flight and think about the role of Reynolds number, or apply physics when studying blood flow in chemistry or biology, then they’re doing what I hope they’ll do. If an instructor mentions the electrical properties of blood, they should be able to draw on physics problem-solving to deepen their understanding—not just memorize the concept.

So, while the earthworm problem has value, I believe it would be stronger as a more open-ended task. For example: “Why do earthworms have limited cross-sectional area per unit length?” Something that invites critical thinking, not just procedural execution.

Presumed Uniformity of Introductory Biology Curricula

I also want to mention another critique of the paper: its assumption about the universality of biology curricula. In adapting Nexus materials at UMass Amherst, I’ve found that our students arrive in IPLS with different backgrounds than those at the University of Maryland. This makes me wonder whether biology curricula vary more than physics curricula across the country.

My conversations with biology colleagues suggest that variation exists even within UMass. For example, Laura Francis emphasizes a mechanistic and quantitative approach, while Caleb Rounds focuses on data literacy and graph interpretation. Others still follow a more traditional memorization-based approach. These differences suggest limitations in the universal applicability of the paper’s ideas.

For this reason, I believe authentic IPLS development requires close collaboration with local biology and chemistry faculty. These partnerships help align course design with the actual experiences of students. A good example is how my focus on HOMO-LUMO transitions in organic chemistry—used to motivate quantum mechanics—emerged from conversations with Laura. Using shared language and figures, and teaching this content simultaneously in chemistry and physics, reinforces its authenticity for students.

In short, one must be cautious when trying to generalize IPLS implementations from one institution to another. Biology prerequisites and emphasis vary, and effective course design must reflect this.

The Importance of Language in Problem Authorship

Another interesting example from the paper involves two different prompts for protein unfolding. The first is essentially a physics problem imposed on a biological context—no more authentic than a cheetah chasing an antelope. While it might be fun, it doesn’t feel authentic to many students, and in my experience, some even resent such forced pairings.

The second prompt, involving the energy landscape, feels much more authentic. In addition to structural differences, a key factor is the use of biologically native language. This aligns with ideas from my mutual mentoring work: authenticity is enhanced when you speak the language of the students.

This is something that I find missing in many IPLS discussions. Language and conventions matter. For example, I used to describe HOMO-LUMO transitions as “excitation from ground to first excited state”—the physicist’s language. Calling it a HOMO-LUMO transition, though, immediately felt more authentic to students. I don’t have hard data to support this, but my classroom experience strongly suggests it helps.

The Value of Level-One Tasks

One final point: what the paper calls “level one” tasks can actually be counterproductive. Many students are perceptive. They recognize when a problem is a forced attempt to make physics seem relevant. When it feels fake, they may conclude that physics has nothing to offer biology. In fact, the paper eventually makes this same point.

What I’ve found effective are tasks where students can draw relevant biological, chemical, or medical conclusions. For example, calculating eyeglass prescriptions based on eyeball size, predicting absorption lines of organic molecules, or solving for a 70 mV membrane potential. These are meaningful, relevant facts, but students often don’t know their origins. When they see physics helping them understand such concepts, engagement increases.

  1. R. R. Hake, Interactive-engagement versus traditional methods: A six-thousand-student survey of mechanics test data for introductory physics courses, American Journal of Physics 66, 64 (1998). ↩︎
  2. E. F. Redish et al., NEXUS/Physics: An interdisciplinary repurposing of physics for biologists, American Journal of Physics 82, 368 (2014). ↩︎

Structuring groups for gender equitable equipment usage in labs – Review

These are my thoughts on

M. Dew, E. M. Stump, and N. G. Holmes, Structuring groups for gender equitable equipment usage in labs, Phys. Rev. Phys. Educ. Res. 21, 010162 (2025).

Listenable on the PaperCast at https://open.spotify.com/episode/6ZG4lZH9dXpUHODtij31Bo?si=bbb689ca533640f4

I would like to examine some of the citations within the introduction. Also, the paper does not discuss the alternative educational goal for a first-semester mechanics lab: cohort formation, which is why we rotate groups. I would be curious to see the impact of semester-long groups on this cohort formation process. However, I am already starting to think that, first, forming our own groups as we currently do is the best approach, and second, that some sort of final exam at the end is almost certainly beneficial. The authors indicate that even in some other studies with group formation that resulted in equitable equipment usage, there was still inequitable computer usage. This phenomenon of inequitable computer usage is definitely something I have observed in the Physics 181 lab. Therefore, some sort of lab practical involving computer usage along with other basic skills seems helpful in establishing equitable use.

Following up, I think there is value in asking students to list people with whom they would like to work, as well as those with whom they would prefer not to be partnered. Finally, I do like the question of whether they would prefer to be in a majority-woman group, a majority-man group, or have no preference. The self-described category will be difficult to manage because of the numbers. We will need to think about an effective way to address that.

The paper seems to suggest that rotating groups is generally detrimental to equitable equipment usage. However, they cite a prior paper by the same author that shows this effect can be mitigated by using partner agreements in conjunction with a lab practical exam. I have already considered implementing a lab practical exam for the 181 lab this coming semester. I also see some value, particularly in the first semester, in rotating groups to facilitate cohort cohesion. Moreover, my groups remain the same for three weeks, as opposed to the two-week duration used in this study. It seems to me that the most optimal system for my particular course and goals would be to rotate groups every experiment—that is, every three weeks—and to include some time at the beginning for a partner agreement. Teaching students how to create and use partner agreements also has value beyond the 181 lab. These students will be working in pairs and groups throughout their undergraduate curriculum, so teaching them how to facilitate those interactions is, in itself, a valuable skill.

In short, I believe the best solution is fixed groups, which I was already planning to implement, combined with partner agreements. I should look up that earlier paper and see exactly how those partner agreements were structured, along with incorporating the lab practical I was already considering.

The Structure of Scientific Revolutions – Review and Application to 13X

I have been reading The Structure of Scientific Revolutions1, and, while dated, I found it quite interesting. I would love to hear the thoughts of a colleague from psychology or sociology. I feel that many of his thoughts and conclusions suffered from, essentially, selection bias as a former practicing physicist: many of his examples are drawn from the history of physics and the adjacent sciences of chemistry and astronomy with few from biology and even fewer from further afield.

However, I did find one thought potentially relevant for my interdisciplinary work with 131 and 132: the question of “Is helium a molecule?” In the text, the author asserts that physicists and chemists gave different answers to this question. A chemist says yes because it behaves like a molecule on the kinetic theory of gases. A physicist, on the other hand, may not say that it is a molecule because it does not possess the interatomic bonds necessary for molecular Construction. This is a cool example and citation for our discussion on different ways of knowing between the different Sciences.

  1. T. S. Kuhn and I. Hacking, The Structure of Scientific Revolutions: 50th Anniversary Edition (University of Chicago Press, Chicago ; London, 2012). ↩︎

Alternative Assessment in Upper-Division Quantum Mechanics

Replacing Midterm Exams with Multi-Attempt Quizzes

This past semester forced me to implement two changes to my Quantum Mechanics II class that I had debating implementing back in January, but decided against to minimize the number of changes. However, midway through the semester, some UMass international students at began to have their visas and statuses revoked. The first student to fall victim to this abuse of government power was a physics undergraduate. This information broke on a Wednesday, and my sole midterm examination was scheduled for the following Tuesday.

I felt that going ahead with the midterm under such circumstances was neither fair nor appropriate without a conversation with the students. Moreover, I felt that I could not delay the midterm by another week because of holidays and snow days had already resulted in the midterm being later than I would have liked. After a discussion with the 12 students in the class, one of the students, who had taken a class from Bill Leonard in our engineering department, proposed the very “mastery model” that I had already considered implementing semester.

The implementation I ultimately decided upon was one similar to one Jennifer Ross, now at Syracuse University, had implemented in her 500-level Optics course here at UMass Amherst several years ago: students have the opportunity to take multiple assessments on every given topic in the form of short two-or-three question quizzes. After seeing their results, students can then elect to take another quiz on the same topic. Only the highest score is kept. Due to the complexities of creating quizzes for QM II, I was forced to restrict the number of attempts to three on each set of topics:

  1. Fundamentals of Angular Momentum (Review from QM I).
  2. Group Theory.
  3. Parity and Translations.
  4. Angular Momentum Addition and Rotation Theory.
  5. Identical Particles and the Periodic Table.

We ended with perturbation theory at the end of the semester and, given the newness of this entire procedure and the limited time for retakes, I did not offer a quiz on this topic.

End-of-Semester Presentations

In addition to replacing the midterm exams with quizzes, I also replaced the end-of-semester final exam with a presentation. For those who may not be familiar, the textbook, Griffiths and Schroeter’s Quantum Mechanics 3rd Edition, follows a format where concepts such as parity are introduced and then applied to interesting physical systems such as crystals. For this final assignment, students worked in pairs and had 25 minutes to present one of these application topics. To make sure that everyone was prepared, and that the topic could be covered in such a small amount of time, there were reading expectations in advance. Students were also expected to ask questions during other students’ presentations. In addition, all teams were told to expect two questions from me that they must be able to answer.

Review

The changes represented a good first attempt. Unfortunately, few students completed the end-of-semester evaluation so I got little feedback from them. My summary of the pros and cons can be found in the table below:

ProsThings to change next time
1. Students have both the opportunity to learn from their mistakes and the incentive to do so.

2. Makeups are not an issue.

3. The end-of-semester presentations are AI proof: students are allowed to use it in preparation though told that AI sometimes gets this level material quite wrong. Moreover, as an instructor I can clearly identify when students rely on AI as they are unable to answer questions. 		1. Many students waited too long to complete the quizzes and thus did not have time to retake, after additional studying, as many times as they otherwise would have.

2. While I did have a rubric, it was clear that many students were unclear on exactly what was expected.

3. Having only a single presentation meant that the opportunity to learn and improve did not exist.

Things to do differently next time

  1. Do it from the beginning!
  2. Have two rounds of presentation: one about midway through and the other at the end so that students can improve their presentation skills too.
  3. Have a timeline for the quizzes so that students cannot get too far behind.
  4. Consult with Bill Leonard, Jennifer Ross, and other experts more deeply for a more considered approach.

A First Crack at Introductory Lab for Physics and Astronomy Majors (Physics 181 Lab)

This past semester saw my first attempt at teaching introductory lab for physics majors (Physics 181 Lab at UMass Amherst). I worked with Chris Ertl, leveraging his expertise in developing labs for Physics 131 inspired by Course-based Undergraduate Research Experiences (CUREs) common in biology1. In CURE lab courses, students explore authentic scientific questions and share their results with the broader scientific community. Development of such curricula is comparatively simple in biology as almost any soil sample will include microorganisms unknown to the literature.

While true CUREs are difficult to construct in physics, as most authentic physics research questions are beyond the reach of introductory students, we strove to incorporate the ideals of this approach as well as synthesize it with both the AAPT’s Recommendations for the Undergraduate Physics Laboratory Curriculum2 and the thoughts expressed in Introductory Labs: We can do Better3 article from Physics Today’s January 2018 edition. We also owe a lot to the prior instructor, Scott Hertel. The resulting course focused on the following goals with the aim to make the experience as close to that students will see in future lab work:

  1. Physics-identity promotion and acculturation: The literature is very clear on the importance of the development of physics-identity, particularly with regards to students whose identities are not traditionally associated with physics4,5. We explore different careers physicists purse from the traditional academic/lab roles to comic-strip authors. Within the research sphere, we discuss the different modalities of theoretical, phenomenological, computational, and experimental along with a bit on what the day-to-day lab work is like for each group. Finally, we discuss some practical aspects of being a physics student including the concept of REUs, getting involved in research and TAing including the financial aspects (that you get paid for REUs and graduate school for example). This last point particularly important for first-generation and international students who may be less familiar with the structure of physics education at the university level in the U.S.
  2. Scientific philosophy and values: Students received explicit instruction into some of the fundamentals of scientific philosophy, such as the logical impossibility of proving things true and the differences between inductive and deductive reasoning. Moreover, helping students understand and appreciate that experiments almost never work the first time was baked into the course from the foundations. Students also engage with the fundamentals of modeling: what variables are important, what can be ignored, etc. as they build their own models from their data.
  3. No “cookie-cutter” labs: All the labs had minimal instructions with regards to procedure forcing students to design the procedures themselves.
  4. Construction of their own apparatus: Instructors of more advanced labs had commented that students in these courses were not comfortable with using equipment as basic as C-clamps. My hypothesis was that this discomfort arose from the structure of prior lab courses: historically, students have entered the lab to find the setup already established by the lab instructional team. Instead, we had, the more authentic, shelf of materials which students could use to construct their own apparatuses.
  5. Understanding uncertainties: Students were explicitly taught the difference between statistical and systematic uncertainties in an explicitly frequentist framework. Moreover, students were expected, by the end of the laboratory, to
  6. Refinement of Procedures: Dovetailing with goals 2-5 above, and inline with the recommendations for CUREs, students are always given time to refine their procedures and try again. Of course, refinement takes time. As a consequence, we only did five labs over thirteen weeks with each lab taking two or three weeks to complete.
  7. No “black boxes”: In order for students to achieve goals 4-6, students must fully understand and be able to calibrate their measurement tools. As such, only the most basic experimental tools are used: rulers, scales, protractors, timers, etc. This is in distinct contrast to prior iterations which used a lot of electronic measuring tools. My issue with these tools is that students can neither innovate nor really understand the uncertainties involved.
  8. Exposure to different subfields of physics: As described in Exploring subfield interest development in undergraduate physics students through social cognitive career theory6, many students are unfamiliar with most physics subfields beyond the “popular” upon entering higher education. Thus, we strove to include labs from multiple subfields including astronomy and granular materials etc. to both expose students to new fields and/or excite those who may already have such an interest.
  9. Exposure to python as a data analysis tool: This course is not designed to be an introduction to programming course – we have one of those which comes later. The programming goals of 181 Lab are simply to expose students to a python programming environment and to begin to get comfortable with manipulating data through text commands. I use the pandas python data analysis library due to is superficial similarities to spreadsheets which most students have at least opened and used in a superficial way.

The result of our collaboration was, I must say, one of the most successful first attempts at a course I have had in a long time. While there are, of course, things to change in the next iteration, I am excited to see how this course develops. Once it is more mature, I will create a dedicated page.

  1. Atreyee Bhattacharya, Pamela Harvey, and Perri Longley, CURE | Course-Based Undergraduate Research Experience (CURE) | University of Colorado Boulder, https://www.colorado.edu/research/cure/home. ↩︎
  2. D. MacIsaac, Report: AAPT Recommendations for the Undergraduate Physics Laboratory Curriculum, The Physics Teacher 53, 253 (2015). http://scitation.aip.org/content/aapt/journal/tpt/53/4/10.1119/1.4914580?ver=pdfcov. ↩︎
  3. N. G. Holmes and C. E. Wieman, Introductory physics labs: We can do better, Physics Today 71, 38 (2018). https://physicstoday.scitation.org/doi/10.1063/PT.3.3816. ↩︎
  4. E. W. Close, J. Conn, and H. G. Close, Becoming physics people: Development of integrated physics identity through the Learning Assistant experience, Phys. Rev. Phys. Educ. Res. 12, 010109 (2016). ↩︎
  5. S. Hyater-Adams, C. Fracchiolla, N. Finkelstein, and K. Hinko, Critical look at physics identity: An operationalized framework for examining race and physics identity, Phys. Rev. Phys. Educ. Res. 14, 010132 (2018). ↩︎
  6. D. Zohrabi Alaee and B. M. Zwickl, Exploring subfield interest development in undergraduate physics students through social cognitive career theory, Phys. Rev. Phys. Educ. Res. 21, 020109 (2025). ↩︎