Lillian C. McDermott, University of Washington

Arnold B. Arons’ perspective on the teaching of physics is reflected in the instructional methods and intellectual criteria that have characterized the work of the Physics Education Group (PEG) at the University of Washington (UW). He had a major impact on my life that was both personal and professional. On being invited to contribute an article in his honor by Richard Steinberg, I realized that I could not completely separate these two aspects.

A. Relevant History Before 1973

In 1968 Ronald Geballe (UW Physics Department Chair) invited Arnold Arons (Physics Professor, Amherst College) to develop a course at UW to prepare prospective elementary school teachers to teach physical science. I offered to help (1969-1970). I could volunteer because I had lost my part-time teaching positions at UW and Seattle University due to the ‘Boeing bust,’ an economic downturn in the local economy.¹

My initial incentive to conduct research in physics education (PER) resulted from my experience as a volunteer instructor in Arnold’s course. Pat Heller (then a Master’s physics student), Jim Minstrell (a high school physics teacher and graduate student in the College of Education), and a few graduate physics TAs were also on the teaching staff. Instead of teaching by telling as most physics instructors do, I gradually started to teach by asking questions and listening to answers by students as I had seen Arnold do. Although I had been aware of the Socratic method from studying philosophy in college and ancient Greek history before then, I had not thought of applying this method to the teaching of physics. I found it challenging to listen carefully to responses by students, to try to determine how they were thinking, and then to ask a series of questions designed to lead them to a correct understanding of the physics involved.

In 1970 I helped Arnold write an NSF proposal for a series of summer programs in Physical Science and Biology for K-6 in-service teachers and some support to write a book. When it was funded, I became a part-time Lecturer in Physics. Our first NSF Summer Program took place in 1971.² Arnold began writing The Various Language.³ (This was the “ancestor” of Physics by Inquiry and Tutorials in Introductory Physics, our group’s two research-based and research- validated curriculum development projects).^4,5 Arnold, I, and our TAs gradually became known as the Physics Education Group. At his request, I began to develop an academic-year course for prospective high school physics teachers. I also admitted students from his course for pre-service elementary school teachers who wanted to continue learning physics.⁶ Both groups met in the same room and benefited from their interaction. The future high school teachers found that formulas would not satisfy their pre-service classmates who had taken Arnold’s course.

During 1972-1973, Arnold was offered a position at the Woods Hole Oceanographic Institute. He negotiated a retention offer from UW that included a new tenure-track faculty position in physics education either in the Provost’s Office or in the Physics Department. Because the physics faculty did not want physics taught outside of the Department, it was decided that the appointment would be there. The position was advertised. Since the anti-nepotism policy had been revoked as unconstitutional in 1972, I could apply. As one of the three finalists, I gave a Physics Department Colloquium and was offered the position of Assistant Professor.

B. Research and Curriculum Development by UW PEG after 1973

My first teaching assignment in my new position was the “combined course” that I had started to develop. I had begun by 1973 to write worksheets suggested by some activities in the Study Guides included in The Various Language. In 1977, I instituted a special preparatory course for students in the UW Equal Opportunity Program (EOP) and others underprepared to succeed in introductory physics, a gateway course for admission to a medical or engineering program. The emphasis in the new course was on reasoning, not formulas. Explanations were required on examinations. When similar qualitative questions were later asked in courses for science majors, many of the same difficulties surfaced. This observation helped motivate me to conduct research in physics education. Although he did not want to undertake such research himself, Arnold enthusiastically encouraged me to do so. The outcome has been the growth of the UW Physics Education Group and widespread adoption of our published curricula.

Perhaps the best way to illustrate Arnold Arons’ influence on our group’s development of curriculum is through illustrations. Three examples follow.

1. Development of the Concept of Density
   The Various Language and the PbI module, Properties of Matter, guide students in formulating operational definitions for mass, volume, and density. The statement that density equals the mass divided by the volume (D = M/V) is often a memorized formula that sometimes results in the query “Is it D = M/V or D = V/M?” Students measure the mass and volume of several objects of different shapes made of homogeneous substances. They find that for a given substance the result of dividing the mass by the volume is the same. When they plot corresponding values of mass and volume, they obtain a straight line with a slope equal to the density. They interpret the ratio as the number of grams for each cm³ of the substance and recognize density as a characteristic property of a substance that helps identify it. (For many students, “grams per cubic centimeter” often does not carry the Latin meaning of “for each.”)
2. Development of Ability in Proportional Reasoning: π = C/d
   A question that Arnold often posed as an example of the application of proportional reasoning is based on the relationship of π (~ 3.14) as the ratio of the circumference (C) to the diameter (d) of all circles. Students are told to imagine a rope wrapped tightly around the earth’s equator (~ 25,000 miles), then lengthened by about six feet and held at a uniform height. The question asked is:
   Which of the following (an amoeba, a bumble bee, a cat, or a camel) would fit under the rope? Explain your reasoning.
   Few people immefiately recognize that C = π d implies ΔC = πΔd. Therefore, if the circumference increases by 6 feet, the diameter increases by about 2 feet and the radius by 1 foot. Thus, a cat is the largest creature that would fit.
3. Development of a Conceptual Model for Electric Current
   The development of a model for electric current from concepts students construct as they investigate the behavior of batteries and bulbs was included in The Various Language. Development of a laboratory-based curriculum was expanded in Physics by Inquiry and Tutorials in Introductory Physics.⁷

C. Summary

Recognition of research in physics education as an important field for investigation in physics departments has grown greatly in recent years. Today, Peter Shaffer, Paula Heron, and I are Professors in the UW Physics Department. Suzanne Brahmia will join our faculty in 2017.

I am deeply grateful to Arnold B. Arons for his guidance when I first began teaching K-12 teachers and for his later support for my research in physics education. He planted the seeds that led to our group’s success. For me, his legacy continues to grow.

Lillian C. McDermott is a Professor of Physics at the University of Washington. A Fellow of APS, AAPT, and AAAS, she received her Ph.D. from Columbia University in 1959 for research in experimental nuclear physics. Since 1973 her research has been in physics education (PER). Under her leadership, the Physics Education Group has conducted research on the learning and teaching of physics and developed instructional materials that are both research-based and research-validated. Since 1979 more than 25 graduate students in the group have earned a physics Ph.D. for PER.

References

¹ My husband, Mark N. McDermott, was on the physics faculty. Strict anti-nepotism rules precluded a position for me.

² These have evolved since then into Summer Institutes in Physics and Physical Science for K-12 in-service teachers.

³ A. Arons, The Various Language: An Inquiry Approach to the Physical Sciences (Oxford U. Press, NY, 1977).

⁴ L.C. McDermott and the Physics Education Group at the U. of Washington, Physics by Inquiry (John Wiley & Sons, NY, 1996).

⁵ L.C. McDermott, P.S. Shaffer, and the Physics Education Group at the University of Washington, Tutorials in Introductory Physics, First Edition (Prentice Hall, Upper Saddle River, NJ, 2002) and Instructor’s Guide (2003). Prentice Hall was subsequently acquired by Pearson International, which will publish the Second Edition in 2016.

⁶ L.C. McDermott, “Combined physics course for future elementary and secondary school teachers”, Am. J. Phys. 42(8), 668 (1974).

⁷ See, for example, L.C. McDermott and P.S. Shaffer, “Research as a guide for curriculum development: An example from introductory electricity, Part I: Investigation of student understanding, Am. J. Phys. 60 (11). 994 (1992) and P.S. Shaffer and L.C. McDermott, ibid., Part II: Design of instructional strategies, ibid., 60 (11), 1003 (1992).

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