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Summary of  “A modeling method for high school physics instruction,” 
Malcolm Wells, David Hestenes, and Gregg Swackhamer, pp. 162–175.
OVERVIEW:
This paper describes the creation, development, initial test-
ing, and preliminary dissemination of a physics instructional 
approach that has come to be called Modeling Instruction. 
The instructional design is centered on models, defi ned as 
conceptual representations of physical systems and proc-
esses; these representations may be both mathematical and 
non-mathematical. There is a particularly strong emphasis on 
the use of qualitative reasoning aided by a diverse array of 
representational tools such as motion graphs, motion maps, 
force diagrams, etc. Such representational tools are consid-
ered essential for competent modeling and problem solving. 
The modeling approach organizes the course content 
around a small number of basic models, such as the “harmonic 
oscillator” and the “particle subject to a constant force.” 
These models describe basic patterns that appear ubiquitously 
in physical phenomena. Students become familiar with the 
structure and versatility of the models by employing them in 
a variety of situations. This includes applications to explain or 
predict physical phenomena as well as to design and interpret 
experiments. Explicit emphasis on basic models focuses stu-
dent attention on the structure of scientifi c knowledge as the 
basis for scientifi c understanding. Reduction of the essential 
course content to a small number of models greatly reduces 
the apparent complexity of the subject. In modeling instruc-
tion, physics problems are solved by creating a model or, 
more often, by adapting a known and explicitly stated model 
to the specifi cations of the problem. 
Students begin each laboratory activity by specifying the 
physical system being investigated, and then identify quan-
titatively measurable parameters that might be expected to 
exhibit some cause/effect relationship, some under direct 
control by the experimenters, others corresponding to the 
effect. The central task is to develop a functional relation-
ship between the specifi ed variables. A brief class discussion 
of the essential elements of the experimental design (which 
parameters will be held constant and which will be varied) 
is pursued, following which the class divides into teams of 
two or three to devise and perform experiments of their own. 
Computer tools are frequently employed for data acquisi-
tion and analysis. Students are guided in their activities and 
discussion through Socratic questioning and remarks by the 
instructor. For a post-lab presentation to the class, the instruc-
tor selects a group which is likely to raise signifi cant issues 
for class discussion—often a group that has taken an inap-
propriate approach. At that time, the group will outline their 
model and supporting argument for public comment and dis-
cussion by the other students.
Modeling instruction is strongly guided by research on stu-
dents’ ideas and misconceptions in physics. These research 
fi ndings are used for course planning, both to improve 
the coherence of the overall course structure and to ensure 
that class activities provide repeated opportunities for stu-
dents to confront all serious misconceptions associated with 
each major topic. Specifi c misconceptions are targeted and 
addressed in connection with each activity in a way that fl ows 
naturally from the manner in which the activities themselves 
are structured. In both problem-solving and laboratory activi-
ties, students are required to articulate their plans and assump-
tions, explain their procedures, and justify their conclusions. 
The modeling method requires students to present and defend 
an explicit model as justifi cation for their conclusions in every 
case; verbal, mathematical, and graphical representations are 
all employed in this analysis. As students are led to articulate 
their reasoning in the course of solving a problem or analyz-
ing an experiment, their naïve beliefs about the physical world 
surface naturally. Rather than dismiss these beliefs as incor-
rect, instructors encourage students to elaborate them and 
evaluate their relevance to the issue at hand in collaborative 
discourse with other students. In pursuit of this goal, substan-
tial amounts of class time are allotted to oral presentations by 
students, including “postmortems” in which students analyze 
and consolidate what they have learned from the laboratory 
activities. In these presentations student groups outline their 
models and their supporting arguments for joint examination 
and public discussion.
This paper outlines how initial testing of the effectiveness 
of the modeling instruction methods was done in high-school 
classes by author Wells and in college classes by a collabo-
rator of the authors. Wells’s students increased their scores 
on research-based mechanics diagnostic tests by about 35% 
in comparison to their pre-instruction scores. This is far 
higher than the 13-21% observed in comparable high-school 
classes taught with traditional methods by other instructors, 
and higher even than Wells’s own students in classes he had 
previously taught using other methods. Similarly, students in 
the college classes taught with the modeling methods showed 
pre- to post-instruction improvements of about 25%, well 
above the 11% observed in comparable classes taught with 
traditional methods.
To develop a practical means for training teachers in the 
modeling method, a series of NSF-supported summer work-
shops for in-service teachers was designed and conducted. The 
fi rst fi ve-week summer workshop was held in 1990, followed 
by similar workshops in 1991 and 1992 which incorporated 
increasing amounts of teacher-developed written curriculum 
materials and greater focus on the pedagogical methods. After 
the fi rst year, scores on the “Force Concept Inventory” diag-
nostic test by the students of the participating teachers were 
greater than they had been before the workshop, but only by 
4%. After the improvements incorporated in the second year, 
these gains had risen substantially to 22%.
During more than two decades following the initial activi-
ties reported in this paper, several thousand high-school phys-
ics teachers throughout the U.S. have participated in Modeling 
Instruction workshops. Data refl ecting learning gains by these 
teachers’ students have been very consistent with the initial 
observations reported in this paper. Further details and docu-
mentation are available on the Modeling Instruction website 
at http://modeling.asu.edu.