How We Restructured Intro Physics Program

Interpreted by Yuichi

Where We StartedThe Introductory Physics

Courses4 lectures/week 50 minutes 200 students

Disconnected lab 2 hours/week 16 students

No recitation sections

Not a popular course to teach or take!

To restructure

• Goals of Physics Classes were re-evaluated.– Survey with “clients” such as engineering

departments which require Physics for their students, and potential employers – industries, government agencies, …

• Pedagogies were also re-evaluated.

What Do Other Faculty Want?

• Goals:Goals: Calculus-based Course (88% engineering majors) 19934.5 Basic principles behind all physics4.5 General qualitative problem solving skills4.4 General quantitative problem solving skills4.2 Apply physics topics covered to new situations4.2 Use with confidence

Goals:Goals: Algebra-based Course (24 different majors) 19874.7 Basic principles behind all physics (e.g., Newton’s Laws)4.2 General qualitative problem solving skills4.2 Overcome misconceptions about physical world4.0 General quantitative problem solving skills4.0 Apply physics topics covered to new situations

Goals:Goals: Biology Majors Course 20034.8 Basic principles behind all physics4.3 General qualitative problem solving skills4.2 Use biological examples of physical principles4.1 General quantitative problem solving skills4.0 Overcome misconceptions about physical world4.0 Apply physics topics covered to real world situations4.0 Know range of applicability of physics principles3.9 Analyze data from physical measurements

Modified survey in response to CBS Curriculum Committee

Employment Private Sector

Gov’t Labs

High Schools

Problem Solving

Interpersonal Skills

Technical Writing

Management Skills

Adv. Computer Skills

Spec. Equip. & Proc.

Business Principles

Statistical Concepts

Knowledge of Physics

Advanced Mathematics

Percent Reporting Frequent Use0 50 0 50 0 50

Survey of Physics Bachelors, 1994-AIP

What we chose to focus

• Problem solving

• Conceptual understanding of Physics– Good goal in its own right– Should help in solving physics problems

Goals we gave up

Be familiar with a wide range of physics topics.

Understand and appreciate “modern physics”(e.g., solid state, quantum mechanics, nuclei, etc.).

Understand and appreciate the historical development and intellectual organization of physics.

Formulate and carry out experiments.

Analyze data from physical measurements.

Use modern measurement tools for physical measurements (e.g., oscilloscopes, etc.).

Program computers to solve physics problems.

Problem Solving a la Martinez

M. Martinez, Phi Delta Kappan, April, 1998

• If you know how to do it, it’s not a problem.

“Process of Moving Toward a Goal When Path is Uncertain.”

“Problem Solving Involves Error and Uncertainty”

A problem for your students is not a problem for you.

(Exercise vs Problem)

How can we teach problem solving?

• By its nature, problems cannot be solved following recipe. In other words, we cannot teach algorithm to solve problems.

• Then what should be the tools to solve problems?– Heuristics– Effective use of algebra

• Equations don’t have to be solvable individually.• Assigning variables to anything you are interested in, and

relating them to your target/known quantities is a good thing to do.

– Metacognitive Skills

What did you learn about Heuristics from Martinez?

• Means - Ends Analysis– identifying goals, – breaking down problem into smaller parts – identifying their sub-goals

• Working Backwards– step by step planning backward from desired result

• Successive Approximations– Rough draft to final manuscript.– In physics, levels of approximation and evaluation

• External Representations– pictures, diagrams, equations, re-statement

Physics-specific Heuristics• Try to apply General Principles of Physics

based on Conceptual understanding

• Students need to learn to judge– Applicability of principle– Relevance of principle– What part of the “system” or whole

• Geometric relations (a2+b2=c2, sinθ=b/c, …)

• “common sense” relations (ω=2π/T, …)

Algebra – its effective use

• Multiple equations can be used together and solved.

• Importance of finding enough equations, disregarding if they can be solved individually to find intermediate solutions

• Importance of defining variables (intermediate goals) which are not the target or unknown variables in the problem.– With them, often equations can be found using physics

principles.

Metacognitive Skills:

Managing time and direction

Determining next step

Monitoring understanding

Asking skeptical questions

Reflecting on own learning process

Discussion session

• This can be on Friday before or after demo

• Preparation before class

• Opening move

• Coaching

• Closure

Preparation before class

• Create appropriately complex problem so that– Heuristic and metacognitive skills are important for

success– Plug-and-chug approach will not work– Good students cannot solve it individually

• Arithmetic (exercise for most students) is not too complex

• Whoever write the problem, it would be ideal if the team discuss pros and cons of the problem based on the above criteria.

Opening move

• Brief: less than 5 minutes.• Establish rapport – small talk before start,

greetings, etc.• Emphasize the focus of the day

– Newton’s Law, Energy conservation, Ampere’s Law, etc.

– Real focus is how to apply them in problems• Choosing the system where the law applies – an object or

system of objects• Confusion between, for example, time intervals and times

Coaching

1. Choose the most urgent group needing coaching (monitoring/diagnosing)

2. Deal with the group (< 5 minutes)

3. Deal with the next urgent group

4. …

5. When 1 is needed, go back to 1

• If common problem is found during 1, may address to the whole class.

End closure

• Reserve at least 5-10 minutes for this.• Decide what part of the solution (focus on

qualitative features) each group present on board.

• Based on your observation during the coaching– Summarize qualitative features of successful

solution(s).– Summarize typical unsuccessful paths and what the

results were, how they fell short of the final goal.– Summarize typical misconceptions (confusion

between velocity and acceleration, vector and scalar,

Lab sessions

1. Before lab2. Opening3. Small group discussion to produce final

solutions4. Closure of problem solving5. Experiment6. Closure of whole process• Another lab problem: return to 2.

Before lab

• Team chooses lab problems to cover and decide the focus of the lab.

• Ask senior TA about possible pitfalls.• If there is pre-lab quiz, analyze the results which

can be used for opening move.• Solve Warm-up Questions and pre-lab quiz

questions.• Go over all the lab, taking data, noting any

computer problems you encounter and tricky points.

Opening move / Group solution

• Very similar to discussion sessions

Solution closure

• Decide what part of solutions groups present on board.

• No need to discuss what is right and what is wrong. Describe qualitative features of various solutions

During experiments

• Watch out for – dysfunctional groups.– Lack of exploration, which leads to

• Too few data points,• Data outside the plotting range

– lousy data (careless measurements), data without any qualitative checks

– Lack of understanding of fitting parameters both to describe data and predictions

– Program/equipment malfunctioning

Final closure

• Re-iterate what physics concept/its application the lab was about.

• If some students did not get where their predictions went wrong, if any, they understand where they went wrong.

• Make sure students know what their experiments should have shown them.