Thomas A. Moore Introductory Calculus-Based Physics Conference November 1, 2003 Six Ideas That Shaped Physics: An Overview.

Thomas A. MooreIntroductory Calculus-Based Physics Conference

November 1, 2003

Six Ideas That Shaped Physics:

An Overview

A textbook, instructor’s manual, and website

A new approach to teaching introductory physics based on four fundamental principles:

1. New approaches can provide increased insight

2. Active learning solidifies understanding

3. Explicit instruction and practice with model-building provides flexibility

4. Contemporary physics provides excitement

What is Six Ideas That Shaped Physics?

To describe the structure and goals of a Six Ideas course

To discuss how the Six Ideas materials express the four principles mentioned

To present evidence that the approach works

My goals in this presentation

NSF-funded project (1987-1995) whose purpose was to develop and test alternatives to the standard course

Summative report: Am. J. Phys. 66, pp. 124-137 (February, 1998)

Principles articulated by the IUPP committee:

1. Less is more

2. Include 20th century physics

3. Use a storyline

The Introductory University Physics Project (IUPP)

The text is divided into six volumes, each focused on a single formative idea

1. Unit C: Interactions are Constrained by Conservation Laws

2. Unit N: The Laws of Physics are Universal

3. Unit R: The Laws of Physics are Frame-Independent

4. Unit E: Electric and Magnetic Fields are Unified

5. Unit Q: Matter Behaves Like Waves

6. Unit T: Some Processes are Irreversible

The structure of Six Ideas

Each idea provides a “story line” for the unit

They also motivate necessary cuts

Some large-scale cuts (geometric optics, fluids)

Mostly, the pace is cut by streamlining

The “chapter per day” format defines the pace

Contemporary physicsUnits on relativity and quantum physics

Contemporary perspective throughout

How this structure addresses the IUPP goals

Common student problems

Identifying forces linked by Newton’s 3rd law

Identifying fictitious forces

These problems are related

Students see forces as isolated entities that are not linked to any deeper conceptual structure

Standard presentations reinforce this

How new approaches can improve learning: an example

In Six Ideas, the interaction between two objects (not force) is the fundamental concept

How this addresses the problem

The forces that are linked by Newton’s 3rd law are always the two ends of a specific interaction

Fictitious forces do not reflect an interaction

How new approaches can improve learning: an example

Other payoffs for this approach:

Helps make the concept of potential energy clearer

Helps students better understand the similarities between force, power, and torque

Momentum-flow images help students qualitatively predict motion without calculus

How new approaches can improve learning: an example

The most robust result of physics educational research: Students learn by doing

We all know this, but our courses are not usually structured as if this were true

Six Ideas supports active learning in four ways:1. Support for reducing the need for lectures2. Support for activities during class3. Support for active learning outside of class4. Support for intelligent course design

Support for Active Learning

Text is written more like a conversation, less like an encyclopedia

Helps for active reading

Wide margins for student notes

In-chapter exercises help challenge students to think about what they are reading (and answers in the back provide instant feedback)

Overview/summary at the beginning of each chapter displays the big picture

Support for Reducing Lectures

Support for class activities

“Two-minute” problems

Active demonstrations

N2T.9 A car moving at a constant speed travels past a valley in the road, as shown below. Which of the arrows shown most closely approximates the direction of the car’s acceleration at the instant that it is at the position shown? (Hint: draw a motion diagram.)

A B C D E F T

zero

A B C D E F T

zero

“Rich-Context” problems support collabo-rative work in active recitation sections

Generally, problems cannot be solved by “plugging and chugging”

Active learning outside of class

C7R.2 You are prospecting for rare metals on a spherical asteroid composed mostly of iron (density ≈ 7800 kg/m3) and whose radius is 4.5 km. You’ve left your spaceship in a circular parking orbit 400 m above the asteroid's surface and gone down to the surface. However, one of your exploratory explosions knocks you against a rock, ruining your jet pack. (This is why you have a backup jet pack, which is, unfortunately, “back up” in the spaceship.) Is it possible for you to simply jump high enough to get back to the spaceship?

To be successful, course design must

Motivate students to read text before class

Help them focus on ideas instead of formulas

Encourage them to learn from difficult problems (instead of freaking out)

Details are important!

The instructor’s manual (available online) offers ideas about how to do this well

Support for good course design

Real applications always involve discerning a simple model in a complex situation

Building a model involves self-consciously making approximations and assumptions

Learning to do this well is an art that students learn by both instruction and practice

Instruction in Model-BuildingWhy is this important?

The text extensively discusses how to build models and make appropriate approximations

It teaches and uses a four-part problem-solving outline: Translate, Model, Solve, Evaluate

It explicitly teaches the value of tools such as unit analysis, symbolic algebra, the method of extremes, estimation

It extensively uses diagrams as thinking tools

Computer models help students explore consequences of physical models

Instruction in Model-Building

Why teach relativity and quantum physics?

Well, this is the 21st century…

32/33 will never take another physics course

One of the clearest signals from IUPP evaluation was the interest in these topics

Six Ideas uses contemporary ideas throughout

It addresses how topics fit into current physics

It explores contemporary applications

Its problems have a very practical orientation

Contemporary Physics

The FCI Exam (Physics Teacher, 30, 3, 1992)(a difficult but purely conceptual multiple-choice exam on Newtonian physics)

R. Hake, Am. J. Phys. 66(1) (January 1998)

The normalized gain g = (post - pre)/(100% - pre)] is a robust measure of course performance

Traditional courses: g = 0.23 ± 0.04

“Interactive engagment” (IE) courses: g = 0.48 ± 0.14

Not correlated with instructor, initial student state

Does Six Ideas work?

Results from Pomona College

1993: 0.46

1996: 0.48

1997: 0.45

1998: 0.55 (estimated)

2000: 0.63

2001: 0.58

Does Six Ideas Work?

Vic DeCarlo at DePauw University2000: 0.542001: 0.55

Ulrich Heinz at Ohio State (Columbus)2001: 0.72 (!)

Note that Six Ideas spends less time on mechanics than most IE courses

Good gains seem to happen even if the classes are not especially interactive

Does Six Ideas Work?

Six Ideas provides (without requiring costly staffing, scheduling, or infrastructure changes)

A contemporary and effective approach to physics

Support for active learning

Explicit instruction in model-building skills

It has been classroom-tested for > 10 years

It provides extensive support for instructors

For more: www.physics.pomona.edu/sixideas

Conclusions