Models and Modeling in the High School Physics Classroom

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Models and Modelingin the High SchoolPhysics
Classroom

Larry Dukerich Modeling Instruction
Program Arizona State University Dobson HS -
Mesa, AZ
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The Problem with Traditional Instruction

• It presumes two kinds of knowledge facts and
  knowhow.
• 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.

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Teaching by Telling is Ineffective

• 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.

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Memorization vs Understanding

• What does it mean when students can readily solve
  the quantitative problem at left, yet not answer
  the conceptual question at right?

For the circuit above, determine the current in
the 4 W resistor and the potential difference
between P and Q.
Bulbs A, B and C are identical. What happens to
the brightness of bulbs A and B when switch S is
closed?
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Instructional Objectives

• 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.

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Why modeling?!

• 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.

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Models vs Problems

• The problem with problem-solving
• 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
• 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.

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What Do We Mean by Model?

• with explicit statements of the relationships
  between these representations

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Multiple Representations

• with explicit statements describing relationships

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How to Teach it?
constructivist vs transmissionist
cooperative inquiry vs lecture/demonstration
student-centered vs
teacher-centered active engagement vs
passive reception student activity
vs teacher demonstration student
articulation vs teacher presentation
lab-based vs textbook-based
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I - Model Development

• Students in cooperative groups
• design and perform experiments.
• use computers to collect and analyze data.
• formulate functional relationship between
  variables.
• evaluate fit to data.

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I - Model Development

• Post-lab analysis
• whiteboard presentation of student findings
• multiple representations
• verbal
• diagrammatic
• graphical
• algebraic
• justification of conclusions

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Preparing Whiteboard
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Making Presentation
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II - Model Deployment

• In post-lab extension, the instructor
• 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.

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II - Model Deployment

• In deployment activities, students

• learn to apply model to variety of related
  situations.
• identify system composition
• accurately represent its structure

• articulate their understanding in oral
  presentations.

• are guided by instructor's questions
• Why did you do that?
• How do you know that?

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II - Model Deployment

• Objectives
• 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
• autonomous scientific thinkers fluent in all
  aspects of conceptual and mathematical modeling.