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Models and Modeling
in the High School
Physics Classroom
Larry Dukerich
Modeling Instruction Program
Arizona State University
Dobson HS - Mesa, AZ
The Problem with Traditional
Instruction
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It presumes two kinds of knowledge: facts and
knowhow.
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Facts and ideas are things that can be packaged into
words and distributed to students.
Knowhow can be packaged as rules or procedures.
We come to understand the structure and
behavior of real objects only by constructing
models.
“Teaching by Telling” is
Ineffective
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Students usually miss the point of what we tell
them.
Key words or concepts do not elicit the same
“schema” for students as they do for us.
Watching the teacher solve problems does not
improve student problem-solving skills.
Memorization vs Understanding
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What does it mean when students can readily
solve the quantitative problem at left, yet not
answer the conceptual question at right?
B
A
S
For the circuit above, determine the
current in the 4 W resistor and the
potential difference between P and Q.
C
Bulbs A, B and C are identical.
What happens to the brightness of
bulbs A and B when switch S is
closed?
Instructional Objectives
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Construct and use scientific models to describe,
to explain, to predict and to control physical
phenomena.
Model physical objects and processes using
diagrammatic, graphical and algebraic
representations.
Small set of basic models as the content core of
physics.
Evaluate scientific models through comparison
with empirical data.
Modeling as the procedural core of scientific
knowledge.
Why modeling?!
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To make students’ classroom experience closer to the
scientific practice of physicists.
To make the coherence of scientific knowledge more
evident to students by making it more explicit.
Construction and testing of math models is a central
activity of research physicists.
Models and Systems are explicitly recognized as major
unifying ideas for all the sciences by the AAAS Project
2061 for the reform of US science education.
Robert Karplus made systems and models central to
the SCIS elementary school science curriculum.
Models vs Problems
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The problem with problem-solving
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Students come to see problems and their answers as the
units of knowledge.
Students fail to see common elements in novel
problems.
“But we never did a problem like this!”
Models as basic units of knowledge
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A few basic models are used again and again with only
minor modifications.
Students identify or create a model and make
inferences from the model to produce a solution.
What Do We Mean by Model?
Symbolic Representations
Verbal
Physical
System
Algebraic
Mental
Model
Diagrammatic
Graphical
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with explicit statements of the relationships
between these representations
Multiple Representations
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with explicit statements describing relationships
How to Teach it?
constructivist
vs
cooperative inquiry
vs
student-centered vs
active engagement
vs
student activity vs
transmissionist
lecture/demonstration
teacher-centered
passive reception
teacher demonstration
student articulation vs teacher presentation
lab-based vs
textbook-based
I - Model Development
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Students in cooperative groups
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design and perform experiments.
use computers to collect and analyze data.
formulate functional relationship between
variables.
evaluate “fit” to data.
I - Model Development
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Post-lab analysis
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whiteboard presentation of student findings
multiple representations
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verbal
diagrammatic
graphical
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algebraic
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justification of conclusions
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Preparing Whiteboard
Making Presentation
II - Model Deployment
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In post-lab extension, the instructor
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brings closure to the experiment.
fleshes out details of the model, relating common
features of various representations.
helps students to abstract the model from the
context in which it was developed.
II - Model Deployment
In deployment activities, students
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learn to apply model to variety of related situations.
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identify system composition
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accurately represent its structure
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articulate their understanding in oral presentations.
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are guided by instructor's questions:
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Why did you do that?
How do you know that?
II - Model Deployment
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Objectives:
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to improve the quality of scientific discourse.
move toward progressive deepening of student
understanding of models and modeling with each
pass through the modeling cycle.
get students to see models everywhere!
Ultimate Objective:
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autonomous scientific thinkers fluent in all aspects
of conceptual and mathematical modeling.