Modeling Instruction started in the high school physics classroom of Malcolm Wells at Marcos de Niza high school in Tempe, Arizona. Already a veteran high school physics teacher in the early 1980s, Wells was dissatisfied with his students’ performance on the Mechanics Diagnostic, a precursor of the now well-known Force Concept Inventory. Influenced by Hestenes’ work advocating for the use of models as a central theme in physics instruction, Wells created and refined instructional practices which guided his high school students to build their own scientific models and Modeling Instruction was born.
The learning process developed in Wells’ high school classroom was described by Hestenes and Wells as the Modeling Cycle, and is similar in structure to Karplus’ Learning Cycle.
Our storylines in Mechanics follow the Wells-Hestenes Modeling Cycle. During this cycle, students identify a testable idea, design experiments, collect data, and look for patterns in their results to construct a scientific model which they represent in multiple ways. Students then use their model to predict outcomes of similar situations. Finally, students are confronted with a novel situation not fully addressed by their model, so they are guided to re-model and begin the process again.
Modeling physics teachers work together to constantly refine the mechanics materials, and multiple storylines have been followed effectively in the classrooms of teachers nationwide. The most recent significant edit of materials available to our members is Mechanics v3, which was developed in 2013, and follows the order shown in the slideshow. In addition, our classroom activities include the following:
- Paradigm lab activities in each unit deliberately address common misconceptions
- Representational tools emphasize richness and connectedness of scientific principles
- Student-to-student discourse and guided inquiry are emphasized, leading learners in developing and then deploying their own scientific models
Follow this link for sample materials from Physics Unit 2 — Constant Velocity. Note that this sample unit does NOT contain any quizzes or tests, and addresses the following objectives:
- Forces (pushes and pulls) are interactions between two objects. Forces between objects are differentiated by the way in which two objects interact.
- Newton’s First Law, the law of inertia.Newton’s First Law: Objects at rest stay at rest, objects in motion stay in motion at constant speed in a straight line unless acted upon by unbalanced forces.
- Newton’s Third Law, forces are interactions (sometimes called the law of action and reaction)Newton’s Third Law: All forces come in pairs; paired forces are equal in magnitude, but opposite in direction. FAB = -FBA
- Quantitatively, forces are measured in Newtons (pounds in the English system). Mass is measured in kilograms.
- Earth’s gravitational field strength at its surface is ~ 10 Newtons of force on every kilogram of mass.
- When analyzing the forces acting on an object:
- draw and label a force diagram for the object
- choose the simplest coordinate axis for analysis: horizontal-vertical or parallel-perpendicular
- break forces not aligned with your coordinate axis into components using trigonometry.
- qualitatively use marks on the vectors to indicate equality and inequality
- write equations for the vector equality marks to quantitatively calculate force values
- recognize that balanced forces always result in constant velocity (including v = 0) and unbalanced forces always cause an acceleration in the same direction as the Fnet.