Volume IV: What works, what matters, what lasts
Student learning in undergraduate physics: The role of discipline-based research on learning & teaching
21st Century Pedagogies
Discipline-based research on learning and teaching differs from traditional education research in that the emphasis is not on educational theory or methodology in the general sense but rather on student understanding of science content. For both intellectual and practical reasons, such research must be conducted by science faculty within science departments. Results from systematic investigations of student understanding indicate that most students encounter similar conceptual and reasoning difficulties when studying a given topic. These can be identified, analyzed and addressed through an iterative process of research, curriculum development and instruction. Moreover, specific difficulties - and effective strategies for addressing them - can often be generalized beyond a particular course, instructor or institution. When documented and reported in professional meetings and publications, this information becomes publicly shared knowledge and forms a basis for further investigation.1 Thus, discipline-based education research shares many characteristics of an empirical applied science.
Curriculum development by the Physics Education Group at the University of Washington illustrates how these findings can guide the development of instructional materials that improve student learning.2 Although the context is physics, analogies can be made to other disciplines.
Results from research on the learning and teaching of physics
Our group has conducted research on student learning of many topics before, during and after university instruction in physics. From interviews with students and from the analysis of responses to quiz and examination questions, we have found that on many qualitative questions students perform no better after a traditional physics course than before. The level of mathematical sophistication of the students does not make a significant difference, nor does the use of typical lecture demonstrations and laboratory experiments. The outcome is essentially the same no matter how large the class or how popular the instructor.3
From these observations we have drawn several generalizations about learning and teaching.4 First, the ability of students to solve standard quantitative problems is often not an adequate criterion for functional understanding. As course grades attest, many students who complete a typical introductory course can solve such problems satisfactorily. However, students are often dependent on formulas and are unable to apply concepts learned in a particular context to different situations. Questions that require qualitative reasoning and verbal explanations provide a better indication of understanding.
Second, we have found that certain conceptual difficulties are not overcome by traditional instruction. Although some difficulties are gradually resolved during instruction, others persist, often through advanced study. If sufficiently serious, they may preclude meaningful learning, even though problem-solving performance may be unaffected.
Another generalization is that students often do not develop a coherent conceptual framework from traditional instruction. In order to apply a concept in a variety of contexts, students must be able to define the concept, distinguish it from other concepts, and recognize its relevance to a physical situation. Unless they have gone through the steps needed to construct the concept, they are unlikely to develop this skill.
Perhaps the most important generalization that has emerged from our work is that traditional instruction does not usually improve the reasoning ability of students. Most traditional courses tend to reinforce a perception of physics as a collection of facts and formula. They do not recognize the critical role of reasoning in physics nor understand what is meant by a physical explanation. Our experience indicates that reasoning skills can be developed if students are required to give careful explanations.
Finally, we conclude that teaching by telling is ineffective for most students. In recalling how they were inspired to pursue physics, instructors often view students as younger versions of themselves. This description fits only the relatively small number of highly motivated students. Most listen passively to lectures without becoming intellectually engaged.
Research-based curriculum development
Research on the learning and teaching of physics has guided two major curriculum development projects by the Physics Education Group: Tutorials in Introductory Physics and Physics by Inquiry. The first is intended to supplement traditional instruction in the introductory course. The second is intended to prepare prospective and practicing teachers to teach science as a process of inquiry.
Tutorials in Introductory Physics: A research-based approach to improving student learning in introductory physics courses
Tutorials in Introductory Physics provides a structure that promotes the active mental engagement of students in the process of learning physics.5 The tutorials are intended to supplement the lectures and textbook of a standard introductory physics course. The emphasis is not on solving the standard quantitative problems found in traditional textbooks, but on the development of important concepts and scientific reasoning skills. The tutorials also provide practice in interpreting various representations (e.g., formulas, graphs, diagrams, verbal descriptions) and in translating back and forth between them. Specific difficulties identified through research are expressly addressed.
At the core of the tutorials are worksheets that consist of carefully structured tasks and questions. These guide students as they work in small groups through the reasoning that is needed to develop and apply important concepts and principles. Answers to the questions are not given. Instead, students are expected to construct answers for themselves through discussions with their classmates and with tutorial instructors, usually graduate teaching assistants or undergraduate peer instructors. The tutorial homework reinforces and extends what is covered in the worksheets. For the tutorials to be most effective, it is important that course examinations include qualitative questions that emphasize the concepts and reasoning skills developed in the tutorials. Preparation of the tutorial instructors, in both the content and instructional approach, is also critical.
Tutorials in Introductory Physics has been developed and tested at the University of Washington over a period of more than ten years, and pilot-tested at other colleges and universities. To date, more than 75,000 copies have been distributed to instructors and students at more than 50 institutions, ranging from large research-oriented universities to community colleges. Pilot sites that have played an especially important role include Harvard University, Purdue University, Georgetown University, the University of Illinois at Urbana-Champaign, the University of Cincinnati, and Pierce County Community College. Translations into Spanish and Greek are complete; translation into German is underway.
Ongoing assessment of the effect on student learning has played a critical role in the development and revision of the tutorials. Results obtained at the UW have been published in articles in peer-reviewed journals, conference proceedings, and other professional publications.6 Accounts of their implementation and assessment at other institutions have also been published.7 In addition to helping improve student ability to solve qualitative problems, student ability to solve quantitative problems has also improved in many instances, often despite reduced course time available for practicing solving such problems.8 Retention of concepts has also been assessed. In one study, students performed at a very high level on a standard multiple-choice test of conceptual understanding in a course in which the tutorials were used; when tested again three years later, their scores were essentially unchanged.9
Implications of research for the preparation of K-12 teachers
Our experience in working with teachers over a period of more than 30 years has led to additional generalizations.10 Teachers should have a strong command of basic physics, be aware of common difficulties, and be able to draw on effective instructional strategies to help students learn. Results from research have shown that this level of competence is unlikely to develop from traditional university instruction in physics. Teachers need to have a deeper understanding than is customarily demanded of undergraduates.
Teachers tend to teach as they have been taught -- both in terms of what they teach and how. Instruction in traditional university courses is usually lecture-based. With or without a laboratory component, these courses are poor role models for teachers. Therefore teachers need the opportunity to learn (or relearn) appropriate content in a manner consistent with how they are expected to teach.
Physics by Inquiry: A research-based approach to preparing K-12 teachers to teach physics as a process of inquiry
Our group has developed instructional materials for special courses for prospective or practicing teachers. Physics by Inquiry consists of a set of laboratory-based modules, all of which require active participation by the learner.11 Experiments and observations provide the basis on which students construct physical concepts and develop analytical reasoning skills. The topics have been chosen to provide teachers with the background needed for teaching K-12 science competently and confidently. Depth is stressed rather than breadth of coverage.
Development of the modules has taken place at the UW in NSF Summer Institutes for Inservice Teachers and in academic-year courses for preservice teachers. Pilot-testing at other colleges and universities has played an important role. To date about 6000 copies have been used in the US and abroad. Translation into Greek and Polish has been completed; translation into Spanish is planned.
Evidence that teachers develop a strong understanding of important basic concepts has been published in a number of articles.12,13 The post-test performance, even of elementary school teachers, often exceeds that of undergraduate science and engineering majors.
1 For a comprehensive list of articles on physics education research, see L.C. McDermott and E.F. Redish, "Resource Letter: PER-1: Physics Education Research," Am. J. Phys. 67 (9) 755 (1999).
2 For recent overviews of research and curriculum development by the Physics Education Group, see: L.C. McDermott, Response for the 2001 Oersted Medal, "Physics education research: The key to student learning," Am. J. Phys. 69 (11) 1127-1137 (2001); and L.C. McDermott, "Physics education research: The key to student learning and teacher preparation," Physics World, January 2004, pp. 40-41.
3 For support for these statements, see Ref. 1 and L.C. McDermott, Millikan Award 1990, "What we teach and what is learned: Closing the gap," Am. J. Phys. 59 (4) 301 (1991).
4 These generalizations are discussed in more detail in L.C. McDermott, Guest Comment: "How we teach and what is learned: Closing the gap," Am. J. Phys. 61 (4) 295 (1993).
5 Tutorials in Introductory Physics, L.C. McDermott, P.S. Shaffer, and the Physics Education Group at the University of Washington (Prentice Hall, Upper Saddle River; Preliminary Edition 1998, First Edition, 2002).
6 For articles by the Physics Education Group in peer-reviewed journals that document the effect on student learning of specific tutorials, see: P.R.L. Heron, M.E. Loverude, P.S. Shaffer, and L.C. McDermott, "Helping students develop an understanding of Archimedes' principle: Research on student understanding, Part II: Development of research-based instructional materials," Am. J. Phys. 71 (11) 1188 (2003); R.E. Scherr, P.S. Shaffer, and S. Vokos, "The challenge of changing deeply held student beliefs about the relativity of simultaneity," Am. J. Phys. 70 (12) 1238 (2002); K. Wosilait, P.R.L. Heron, P.S. Shaffer, and L.C. McDermott, "Addressing student difficulties in applying a wave model to the interference and diffraction of light," Phys. Educ. Res., Am. J. Phys. Suppl. 67 (7) S5 (1999); K. Wosilait, P.R.L. Heron, P.S. Shaffer, and L.C. McDermott, "Development and assessment of a research-based tutorial on light and shadow," Am. J. Phys. 66 (10) 906 (1998); T. O'Brien Pride, S. Vokos, and L.C. McDermott, "The challenge of matching learning assessments to teaching goals: An example from the work-energy and impulse-momentum theorems," Am. J. Phys. 66 (2) 147 (1998); R.N. Steinberg, G.E. Oberem and L.C. McDermott, "Development of a computer-based tutorial on the photoelectric effect," Am. J. Phys. 64 (11) 1370 (1996); L.C. McDermott, P.S. Shaffer and M.D. Somers, "Research as a guide for teaching introductory mechanics: An illustration in the context of the Atwood's machine," Am. J. Phys. 62 (1) 46 (1994), and 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; Part II: Design of instructional strategies," Am. J. Phys. 60 (11) 1003 (1992).
7 For articles in peer-reviewed journals that document the effect on student learning of tutorials at other institutions, see, for example, G.E. Francis, J.P. Adams, and E.J. Noonan, "Do they stay fixed?," The Phys. Teach., 36, 488 (1998) and E.F. Redish, J.M. Saul, and R.N. Steinberg, "On the effectiveness of active-engagement microcomputer-based laboratories," Am. J. Phys. 65, (1997).
8 See, for example, B.S. Ambrose, P.S. Shaffer, R.N. Steinberg, and L.C. McDermott, "An investigation of student understanding of single-slit diffraction and double-slit interference," Am. J. Phys. 67 (2) 146 (1999).
9 See the first article in Ref. 7.
10 The approach of the PEG to teacher education is discussed in more detail in: L.C. McDermott, "A perspective on teacher preparation in physics and other sciences: The need for special courses for teachers," Am. J. Phys. 58 (8) 734 (1990); L.C. McDermott, "A university-based physicist discusses concept formation in the laboratory," in Inquiry and the National Science Education Standards--A Guide for Teaching and Learning, (National Academy Press, Washington DC, 2000), pp. 93-94; L.C. McDermott and L.S. DeWater, "The need for special science courses for teachers: Two perspectives," in Inquiring into Inquiry Learning in Teaching and Science, J. Minstrell and E.H. van Zee, eds., (AAAS, Washington, DC, 2000), pp. 241-257; and L.C. McDermott and P.S. Shaffer, "Preparing teachers to teach physics and physical science by inquiry," in The Role of Physics Departments in Preparing K-12 Teachers, G. Buck, J. Hehn, D. Leslie-Pelecky, eds., (American Institute of Physics, College Park, MD, 2000) pp. 71-85.
11 Physics by Inquiry, L.C. McDermott and the Physics Education Group at the University of Washington (Wiley, New York, 1996). See also Physics by Inquiry: A Video Resource, (WGBH Educational Foundation, Boston, 2000).
12 For articles by the Physics Education Group in peer-reviewed journals that document the effect on student learning of courses based on Physics by Inquiry, see the first and last articles in Ref. 6 as well as L.C. McDermott, P.S. Shaffer, and C.P. Constantinou, "Preparing teachers to teach physics and physical science by inquiry," Physics Education 35 (6) 411 (2000).
13 For articles in peer-reviewed journals that document the effect on student learning of courses based on Physics by Inquiry at other institutions, see K.C. Trundle, R.K. Atwood, and J.E. Christopher, "Preservice elementary teachers' conceptions of moon phases before and after instruction," J. Res Sci. Teach. 39, 633 (2002) and B. Thacker, E. Kim, K. Trefz, and S.M. Lea, "Comparing problem solving performance of physics students in inquiry-based and traditional introductory physics courses," Am. J. Phys., 62, 627 (1994).