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The Evolution of Physics Education:
The Evolution of Physics Education:
How Undergraduate Departments Are TransformingBy:
Laurie E. McNeil, Bernard Gray Distinguished Professor, Department of Physics and Astronomy, University of North Carolina at Chapel Hill
What do you remember about your physics education? Lectures on quantum mechanics? Long nights struggling with homework? Any mention of physics careers? Classmates who looked a lot like you? If you went back to your old physics department, you might find that everything is much the same as you remember. But depending on the department (and when you graduated), you might find the scene a bit different.
Who is studying physics now?
Things are looking up for our discipline. The number of physics bachelor’s degrees awarded each year has never been higher—9,193 in the class of 2019. 1 This is up from a modern-day low of 3,646 graduates in 1999, the nadir of a decade-long trend that, had it continued, would have led to zero physics graduates by about 2016. The “market share” for physics is up as well, with physics graduates representing 0.46 percent of all bachelor’s recipients, up from 0.3 percent in 1999.
The gender balance has changed too. In 2019, 24 percent of all physics graduates were female (about the same as in 1999), compared to 5 percent in 1966. Physics programs remain largely white, however—in 2019 only 4 percent of physics graduates were Black and 10 percent were Latinx, compared to 14 percent and 22 percent, respectively, of the college-age population. 2 The physics community as a whole has a lot of work yet to do on diversity and inclusion.
How has teaching changed?
If what you remember about your physics classes is lectures (stimulating or otherwise) and homework (impossible or otherwise), you have lots of company. Most of us were taught by pedagogical autodidacts who had no information other than their own experience about what works (and what does not) in the physics classroom. But that is changing (not fast enough!) with the rise of physics education research (PER) as a subdiscipline in the physics community. Physicists who do PER use rigorous scientific methods to study how people learn physics and how physics education can be improved.3
The findings from PER are many and varied, but if one had to draw a single conclusion from the body of research, it would be this: Interactive engagement works better than traditional lecture instruction. Students learn more by discussion and experimentation in the classroom than they do by listening to lectures, or in the words of the late Professor Lillian McDermott from the University of Washington, “Teaching by telling is an ineffective mode of instruction.”
One way to measure this is to compare students’ gain in understanding of physics ideas through a “concept inventory,” a set of multiple-choice questions that explore students’ understanding of basic concepts such as Newton’s third law. For example, a question might ask which vehicle exerts more force on the other when a large truck and small compact car collide. Students complete an inventory at the beginning and end of a physics course, and the degree to which their understanding has changed (expressed as a fraction of the possible shift toward the correct answers) is recorded as the “normalized gain.”
Before taking a first course in Newtonian mechanics, 75 to 80 percent of students say that the truck exerts more force on the car than the car does on the truck. After traditional lecture instruction, about 65 percent give the same answer! But interactive engagement makes a difference. Classes taught using these methods are much more likely to achieve large gains in understanding of Newtonian mechanics than are classes taught using traditional lectures (see Fig. 1).
These kinds of findings have convinced an increasing number of physics faculty members to change the way they teach. Some departments have undertaken large-scale transformations of introductory physics instruction. Gary Gladding, who led the effort at the University of Illinois at Urbana-Champaign, likened it to “parallel parking an aircraft carrier” because of its scale—over 3,000 students each semester. I led my own department’s similar effort, which at around 1,100 students per semester was more like parking a frigate. In other departments the changes have been more modest, instigated by one or two faculty members.4
What do these new physics classes look like?
There are many ways to implement interactive engagement, but I can give you a flavor by describing the introductory classes at my own institution.
Before coming to class, the students complete a warm-up assignment that may involve reading from the textbook or watching a video before answering questions online. They then attend a lecture in which a faculty member spends most of the time posing questions to the class. Students discuss each question with their neighbors (a technique sometimes called think-pair-share) and then use a personal response device (a “clicker”) to give their answers. If most answers are incorrect, the instructor goes over the idea in more detail and addresses the misconceptions that the students’ answers reveal before asking them to respond again. Once most of the students have grasped the concept, the instructor moves on.
The next meeting takes place in a classroom with round tables that seat nine students each. Here they work in groups of three on pencil-and-paper tutorial activities, guided-inquiry laboratory experiments, and cooperative group problem-solving, all designed based on findings from PER. The instructor circulates as the students work, answering questions and engaging in Socratic dialog. In this way students spend the vast majority of class time actively engaged in thinking about and discussing physics, challenging each other’s understanding and explaining things to each other. Afterward they cement their understanding individually by solving conventional homework problems.
Similar techniques are applied in upper-division classes for physics majors, which have smaller enrollments. Here, students learn about topics in advance, then spend most of the class time applying what they’ve learned by working through carefully designed activities and discussing ideas with each other rather than listening to the instructor. The information transfer takes place individually, but the information application (which is much more difficult) takes place with guidance and assistance from the instructor and from peers. This works just as well for learning about quantum-mechanical orbital momentum operators as it does for learning Newton’s second law.
How is content evolving?
The “standard curriculum” (classical mechanics, electricity and magnetism, quantum mechanics, and thermodynamics) is alive and well in virtually every undergraduate physics department, but increasingly departments seek to broaden physics education and attract more majors by providing interdisciplinary tracks within the major. Such tracks might focus on biophysics, astrophysics, computational physics, or even business and entrepreneurship (colloquially known as “phys/biz”).
The importance of acquiring computational skills is widely recognized, and in some departments this is woven throughout the curriculum by incorporating computational exercises in most or all classes. Groups such as the Partnership for the Integration of Computation into Undergraduate Physics5 (PICUP) foster this by holding workshops and sharing instructional materials and exercises. Physics laboratory skills (beyond that Milliken oil drop experiment that gave us all headaches) are also emphasized with the help of groups like the Advanced Laboratory Physics Association6 (ALPhA), which fosters communication and engagement among the instructors of advanced physics laboratories. There is even an APS prize for excellence in advanced laboratory instruction!7
These trends accord well with the recommendations from a report prepared by a team from APS and AAPT entitled “Phys21: Preparing Physics Students for 21st-Century Careers.”8 That group (which I co-led with Paula Heron of the University of Washington) assembled information about what knowledge and skills employers of physicists are seeking today and how physics departments can help their students acquire them. The report describes broad agreement among employers about the need for physics-specific knowledge (well covered in the traditional curriculum), scientific and technical skills (including coding, data analytics, and instrumentation, as well as the ability to solve ill-posed problems), communications skills (for all types of audiences), and professional and workplace skills (such as working in diverse teams, project management, and knowledge of career opportunities and job seeking). I suspect that this list includes many things needed to do a job effectively, but most of them have not been a part of the traditional physics curriculum. That’s changing now as physics departments increasingly recognize that not all of their graduates will become physics professors and instead must be well prepared for the careers they will actually pursue.
Many physics departments are also recognizing their role in preparing high school physics teachers. Physics is among the hardest disciplines to find teachers for—only 47 percent of high school physics classes are taught by someone with a physics degree. At the same time, enrollment in physics in US high schools is growing. Because today’s college physics students were yesterday’s high school physics students, many physics departments (including my own) have created programs to prepare their majors to become high school teachers, an effort to ensure that incoming students are taught by instructors who know physics well and have enthusiasm for the subject.9 A few states (such as New York and Utah) are producing enough new physics teachers to meet as much as 65 percent of their need each year, but over half of the states are still meeting 20 percent or less of their need. There is considerable room for improvement.
What can we expect in the future?
Certainly the trends of wider adoption of interactive engagement pedagogy, interdisciplinary education, intentional career training, and teacher preparation by physics departments are likely to continue. The next challenges will come from the need to prepare physics students for new kinds of careers that are only beginning to emerge. The current emphasis on quantum computing suggests the need for a “quantum workforce” with lab skills (particularly optics and photonics), as well as engineering and collaborative coding skills, which physics programs can certainly provide. Data science is another emerging area and includes not only dealing with “big data” in scientific contexts but also applying data analytics to business decision-making.
Physicists often work with big data sets that require sophisticated statistical analysis—think of the discovery of the Higgs boson at CERN. There is now even an APS Topical Group on Data Science that focuses on big data, machine learning, and artificial intelligence.
No doubt there will be other trends we can’t predict, and physicists will rise to those challenges as well. After all, as Rush Holt, physicist and former member of the US House of Representatives, is said to have remarked, “Physicists are omnicompetent.”
1. Statistics referenced in this article were obtained from the American Institute of Physics (AIP) Statistical Research Center, https://www.aip.org/statistics.
2. The American Physical Society (APS) and the American Association of Physics Teachers (AAPT), among others, support the STEP-UP project (https://engage.aps.org/stepup/about/overview) to enlist high school physics teachers to engage and inspire young women to study physics. AIP supports the TEAM-UP Project (Task Force to Elevate African American Representation in Undergraduate Physics & Astronomy, https://www.aip.org/diversity-initiatives/team-up-task-force) to address the persistent underrepresentation of Blacks in physics. Partial funding for TEAM-UP is provided by the Research Corporation for Science Advancement.
3. Both APS and AAPT have topical groups on PER, and in 1999 APS issued a statement (https://www.aps.org/policy/statements/99_2.cfm) that PER “has advanced our understanding of student learning in physics and has resulted in significant improvements in the methodology of teaching.” The prestigious Physical Review family of journals has one devoted to PER (https://journals.aps.org/prper/) that published 99 research articles in 2019.
4. In many cases those faculty members were inspired by attending the New Faculty Workshop (https://www.aapt.org/Conferences/newfaculty/nfw.cfm), sponsored by APS, AAPT, AIP, the American Astronomical Society (AAS), and the National Science Foundation (NSF). Faculty members in their first few years of teaching learn about findings from PER and how to use them in their classrooms. About 2,600 faculty members from 85 percent of US institutions that offer physics degrees have attended since the workshop began in 1996, and it now reaches about 35 percent of all new tenure-track physics and astronomy faculty members.
9. APS and AAPT have been especially active in this regard by organizing the Physics Teacher Education Coalition (PhysTEC) (https://www.phystec.org/) “to promote and improve the education of future physics teachers.” Over 300 institutions have joined PhysTEC, and if each college or university in the US were to produce one more teacher each year, the shortage would be eliminated.
10. Joshua Von Korff, Benjamin Archibeque, K. Alison Gomez, Tyrel Heckendorf, Sarah B. McKagan, Eleanor C. Sayer, Edward W. Schenk, Chase Shepherd, and Lane Sorell, “Secondary Analysis of Teaching Methods in Introductory Physics: A 50k-Student Study,” Am. J. Phys. 84 (2016): 969.