Inquiry: A research-based approach to
preparing K-12 teachers of physics and physical science
Lillian C. McDermott, Paula R.L. Heron and Peter S.
Shaffer, Department of Physics, University of Washington, Seattle, WA
Physics Education Group at the University of Washington (UW) has been conducting special
courses for K-12 teachers for more than 30 years. We
have developed a sequence of academic-year courses for prospective elementary and middle
school teachers and another sequence for prospective high school teachers.[i] We also conduct an intensive NSF-funded six-week
Summer Institute for Inservice Teachers that has similar goals. The materials used in both our preservice and
inservice courses are drawn from Physics by Inquiry
(PbI), a self-contained, laboratory-based curriculum that we have developed for use in
university courses to prepare K-12 teachers to teach physics and physical science.[ii] The emphasis in this paper is on elementary and
middle school. However, most of the
discussion is applicable to the preparation of high school teachers.
of research-based instructional approach
have selected electric circuits as a context in which to illustrate the instructional
approach that has guided our development of PbI
and our special courses for teachers. This
topic is included in all K-12 standards-based science curricula. In particular, activities based on batteries and
bulbs are common in elementary school. The
equipment is inexpensive. There is a solid
research base and a documented record of effectiveness.[iii] An additional motivation for this choice of topic
is the availability of several published articles that should be helpful to faculty who
may want to use the curriculum.3
A. Investigation of
by our group on student understanding of electric circuits has extended over a period of
many years. Since the results are well known
by now, only a brief discussion of one question is presented here. In Fig. 1 are three circuits containing identical
bulbs and identical ideal batteries. The
question asks for a ranking by brightness of the five bulbs and an explanation of
reasoning. The correct response is
Figure 1: The five bulbs are identical and the batteries are
identical and ideal. Rank the five bulbs from
brightest to dimmest. Explain your reasoning.
question was administered to more than 1000 students in introductory calculus-based
physics. Before or after standard instruction
in lecture and laboratory, student performance was essentially the same. Only about 15% of the students have responded
correctly. The same question produced similar
results when administered to high school physics teachers and to university faculty in
other sciences and mathematics, all of whom had studied introductory physics. Analysis of the responses enabled us to identify
specific difficulties. Two common mistaken
beliefs were that the battery is a constant current source and that current is "used
up" in a circuit. Most responses
indicated lack of a conceptual model for a simple circuit.
Reliance on rote use of inappropriate formulas was common. When the same question was posed to graduate
students in the UW Physics Ph.D. program (many of whom are TA's in introductory physics),
about 70% answered correctly. These findings
motivated the development of the Electric Circuits
module in PbI and the corresponding tutorial in Tutorials in Introductory Physics.[iv]
B. Instruction by guided
prepare teachers to teach the topic of electric circuits by inquiry, we engage them in the
step-by-step process of constructing a qualitative model that they can use to predict and
explain the behavior of circuits consisting of batteries and bulbs.[v] The students are guided through carefully
sequenced activities and questions to make observations that they can use as the basis for
their model. They begin by trying to light a
small bulb with a battery and a single wire. They
develop an operational definition for a complete circuit. Exploring the effect of adding more bulbs and wires to the circuit, they
find that their observations are consistent with the assumptions that a current exists in
a complete circuit and that the relative brightness of identical bulbs indicates the
relative magnitude of the current. In other
experiments - some suggested, some of their own devising - they find that the brightness
of individual bulbs depends both on how many are in the circuit and on how they are
connected to the battery and to one another. They
construct the concept of electrical resistance and find that they can predict the behavior
of many, but not all, circuits of identical bulbs. They
recognize the need to extend their model beyond current and resistance to include the
concept of voltage (later refined to potential difference).
bulbs of different resistance and additional batteries are added, the students find that
they need additional concepts to account for the behavior of more complicated circuits. They are guided in developing more complex
concepts, such as electrical power and energy. Through
deductive and inductive reasoning, the students construct a model that can account for
relative brightness in any circuit consisting of batteries and bulbs. Throughout the entire process of model
development, the curriculum addresses specific difficulties that have been identified
need to synthesize what they have learned, to reflect on how their understanding has
evolved, and to try to identify critical issues that need to be addressed for meaningful
learning to occur. As they progress in their
investigation of electric circuits, the students are given many opportunities to express
their ideas in writing.
C. Assessment of
many of the elementary teachers in our courses have had considerably less preparation in
physics than students in the standard introductory courses, their performance on
qualitative questions has been consistently better. The
circuit in Fig. 2 provides a good example of what teachers without a strong mathematical
background, but with good conceptual understanding, can do. The students are asked to rank the bulbs according to brightness. Reasoning on the basis of a model based on the
concepts of current and resistance, almost all elementary teachers who have taken our
courses predict correctly that E>A=B>C=D. This
question is beyond the capability of most college and university students who have had
standard instruction in introductory physics.
Figure 2: The five bulbs are identical and the battery is
ideal. Rank the five bulbs from brightest to
dimmest. Explain your reasoning.
evidence for the effectiveness of this approach comes from the University of Cyprus, where
the performance of two groups of prospective elementary school teachers was compared. (Fig. 3.) Both
groups were taught by instructors who understood the material well and who taught in a
manner consistent with constructivist pedagogy (i.e.,
the students were engaged in constructing their own understanding). One of the groups had studied electric circuits in
PbI. [vi] This group consisted of two classes: one had just completed study of the material; the
other class had done so the previous year. The
second group had just completed the topic. They
had been given "hands-on" experience with batteries and bulbs but the
instruction they had received had not been guided by findings from research. Specific difficulties had not been explicitly
addressed nor had the same emphasis been placed on the development of a coherent
3: Student performance on free response and
on multiple-choice questions on a post-instruction survey on electric circuits. The survey was administered to preservice
elementary school teachers at the University of Cyprus.
Two main groups of students were included in the survey: those who had used Physics by Inquiry (PbI) and those who
had not. Some of the students had studied PbI
one year before taking the test (Past PbI). All the others (Present PbI and Other)
had just completed their study of this topic.
groups were given two types of post-tests: one consisted of free-response questions that
asked for explanations of reasoning; the other contained multiple-choice questions taken
from a multiple-choice test that has since been published.[vii] Both classes of students who had studied the
material in Physics by Inquiry had mean scores
greater than 80% on both tests. In the other
group, mean scores were slightly above 40% on the multiple-choice test and less than 20%
on the free-response test.[viii] Courses in which educational methodology is
emphasized without sufficient emphasis on concept development seem to be no more effective
than standard physics instruction.
II. Courses in physics and physical science for
from research convinced us of the need to offer special physics courses for teachers. In all of these courses, all instruction takes
place in the laboratory. There is no
lecturing and only simple equipment is used.
course for elementary school teachers does not proceed through the traditional physics
sequence (kinematics, dynamics, electricity and magnetism, waves and optics). Instead,
the topics have been selected to provide a firm foundation for teaching elementary school
physical science. The module Electric Circuits discussed above is one example. In Properties
of Matter, which probably is the best module with which to begin a course for
elementary school teachers, students begin by constructing operational definitions for
mass, volume, and density. They apply these
concepts in predicting and explaining outcomes in situations of gradually increasing
complexity, culminating with sinking and floating. PbI also includes modules on heat and temperature,
magnetism, light and color, the sun and moon, and other phenomena encountered in daily
course for high school teachers, the students revisit many of the main topics in the
introductory physics course (which is a prerequisite).
These include kinematics, dynamics, waves, optics, electric circuits, and a few
topics from modern physics. Graduate students
in physics, mathematics, and other sciences often participate in this course, either as
enrolled students or TA's. The course has
provided a very positive environment for the preparation of future faculty to work
productively with K-12 teachers.
of the modules in Physics by Inquiry, there is
a strong emphasis on the development of important scientific skills, such as
distinguishing between observations and inferences, controlling variables, proportional
reasoning, deductive and inductive reasoning, etc. PbI
fosters the simultaneous development of physical concepts, reasoning ability, and
representational skills within a coherent body of content. The teachers go through the reasoning in depth and are guided in
synthesizing what they have learned into a coherent conceptual framework. Since effective use of a particular instructional
strategy is often content-specific, instructional methods are taught by example. If teaching methods are not studied in the context
in which they are to be implemented, teachers may be unable to identify the elements that
are critical. Thus they may not be able to
adapt an instructional strategy that has been presented in general terms to specific
subject matter or to new situations.
addition to the courses described above, we offer a weekly Continuation Course that is
open to all teachers within commuting distance of the UW who have participated in any of
our preservice and inservice courses. The
Continuation Course provides an opportunity for teachers to learn more physics and to
consult on how best to apply what they have learned to K-12 classrooms. More importantly, the teachers develop a sense of
community and mutual support. Teaching K-12
physics and physical science is often a professionally isolated activity. The Continuation Course has proved to be a major
contributor to the long-term sustainability of our teacher preparation program.
instructional approach, which has been illustrated in the context of electric circuits,
has proved effective with teachers at all levels from elementary through high school. The process of hypothesizing, testing, extending,
and refining a conceptual model to the point that it can be used to predict and explain a
range of phenomena is the heart of the scientific method. It is a process that must be experienced to be understood.
have been able to show that the demands in our courses for teachers match, or exceed,
those of other physics courses at comparable levels. We have found that the sense of empowerment that results when teachers have
developed a sound conceptual understanding of the science content that they are expected
to teach greatly increases their confidence in their ability to deal with unexpected
situations in the classroom.
paper draws on the cumulative experience of past and present members of the Physics
Education Group. Lezlie S. DeWater, and Donna
Messina, K-12 teachers with our group, have made major contributions. We appreciate the support provided by the
University of Washington Physics Department and the National Science Foundation.
[i] See L.C. McDermott, "Combined
physics course for future elementary and secondary school teachers," Am. J. Phys. 42, 668-676 (1974) and L.C. McDermott,
"Improving high school physics teacher preparation," Phys. Teach. 13, 523-529 (1975).
[ii] L. C. McDermott and the Physics Education
Group at the University of Washington, Physics by
Inquiry, Vols. I and II, (John Wiley & Sons Inc., New York NY, 1996).
[iii] 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, 994-1003 (1992); Printer's Erratum to Part I,
81 (1993); and P.S. Shaffer and L.C. McDermott, "Research as a guide for curriculum
development: an example from introductory electricity, Part II: Design of instructional strategies," ibid. 60,
1003-1013 (1992); L.C. McDermott, P.S. Shaffer, and C.P. Constantinou, "Preparing
teachers to teach physics and physical science by inquiry," Phys. Educ. 35 (6) 411-416 (2000).
[iv] L.C. McDermott, P.S.
Shaffer, and the Physics Education Group at the University of Washington, Tutorials in Introductory Physics, (Prentice Hall,
Upper Saddle River NJ, 2002).
[v] The instructional sequence can be found in
the Electric Circuits module in Volume II of Physics by Inquiry.
(See Ref. 2.)
[vi] A Greek edition of Physics by Inquiry was used.
[vii] P.V. Engelhardt and R.J. Beichner, "Students'
understanding of direct current resistive electrical circuits," Am. J. Phys. 72, 98-115 (2004).
[viii] This study is discussed in
greater detail in the last article in Ref. 3.
Lillian C. McDermott, Peter S.
Shaffer, and Paula R.L. Heron are faculty members in the Physics Education Group in the
Physics Department at the University of Washington. The
group consists of physics graduate students, postdocs, faculty and K-12 teachers who
conduct a coordinated program of research, curriculum development, and instruction to
improve student learning in physics (K-20). The
group is engaged in ongoing research on the learning and teaching of physics that has
resulted in more than 50 research articles. For
more than 30 years, they have been deeply involved in the preparation of prospective and
practicing teachers to teach physics and physical science by inquiry. The group has also published research-based
tutorials to improve the effectiveness of instruction in introductory university physics.