Teaching a Course to Non-Majors Dr. Johnny B. Holmes Dean of the School of Sciences, and Professor...

Teaching a Course to Non-Majors

Dr. Johnny B. Holmes

Dean of the School of Sciences, and Professor of Physics

Excellence in Teaching Workshop at CBU, August 15, 2002

Five Elements

I. Show Enthusiasm and Love of Subject

II. Provide a Framework for the Subject

III. Build on What Students Already Know about the Subject

IV. Provide (Graded) Practice

V. Remove Excuses for Failure


People like to associate with fun people.Show enthusiasmSuggest surprise (absurd) answersSprinkle in humor (positive, not negative humor)

People like to do fun things.Show demonstrations

Make sure you show that the subject is fun and not just the instructor!


Enthusiasm

When I teach, I get excited because I find the material is so interesting and fun. I think it is essential to try to show that enthusiasm to my students. Several have told me directly that they enjoy my class because they like to watch me be so energetic and enthusiastic!


EnthusiasmI have found it very useful to “talk” to the students

about the subject. I do this by asking a lot of questions - some rhetorical and some that I expect an answer. I seldom take the first answer as the answer for the whole class, though. I will ask others if they agree or disagree with it. If there is more than one answer suggested, I may ask the class to “vote” for their choice. After the vote, I will ask one of the voters to defend their vote, and then ask another from the other side as well.


Surprise AnswersSometimes, though, especially if the class is not

responding, I will suggest a “surprise” answer. Example: Question: How do you stop a car? Obvious Answer: Step on the brake. Surprise Answer: Why not just open the door and drag your foot? Follow-up question: How does the brake work - do you need the engine on to have the brake work?


Surprise answersAnother Example: Question: How does

gravity work? Surprise Answer: There are little devils on the floor that lasso you and pull you down when you jump up. A famous basketball player paid them off so he could jump high. He got tired of paying the extortion, so he quit. He earned enough making commercials, so he un-retired.


DemonstrationsPeople learn a lot by “seeing”. We even use the

expression “I see” to mean “I understand”.Computer are very good at calculations, but it is

extremely hard to program a computer to interpret a picture or diagram. People, on the other hand, are not very good at making lots of calculations accurately, but people are very good at interpreting pictures and diagrams - at getting information by sight. Demonstrations take advantage of this natural human ability.


DemonstrationsDepending on the subject, some

demonstrations take a lot of equipment and preparation.

Other demonstrations can be done with common things and little if any preparation.

Sometimes, you can even use the student’s own experiences as “demonstrations”.


DemonstrationsExample: Open versus closed universe. Can we have a

universe that has a finite amount of volume but no edges (a closed universe)? Demonstration: A line is one dimensional (needing one number to locate any point). Can you have a line with no edges but a finite length? Yes - if you curve the line into a circle. A surface is a two dimensional situation. Can you have a surface with no edge but a finite area? Yes - if you curve it into a sphere. Now - what about a three dimensional volume?


• Where is the course going?

• Identify major elements

• Distinguish major principles from details

How to show this to students?– Syllabus– Study Guides– Notes (powerpoint slides)


The next several slides show the goals for my PHYS 201 Introductory Physics I class this fall as contained in the syllabus:

GOALS: The course is designed to: 1. Teach the concepts of vectors, inertia, force,

energy, power, and heat; to introduce Newton's laws of motion & law of gravity; conservation laws of energy, momentum and angular momentum; 1st and 2nd laws of thermodynamics:


Goals for PHYS 201 - cont:1 a) To provide a fund of concepts, images, and

metaphors that can be utilized to imagine how other things in the world might work.

1 b) To give you an idea of the size of some quantities (e.g., size of the earth, power of a normal human heart, values for coefficients of friction of common substances).

1 c) For use in future courses.


Goals for PHYS 201 - cont:1 d) To aid you in your attempt to find your place in

the natural world as well as to aid you in your attempt to become an intelligent and responsible citizen.

2. Demonstrate how physical phenomena can be organized and described both qualitatively and quantitatively by theory.

3. Reinforce the application of analytical reasoning.


My complete syllabus, as well as my study guides and powerpoint slides (class notes) for the PHYS 201 course can be found on the web at:

http://www.cbu.edu/~jholmes/P201/intro.html

In this talk I am trying to model how I use powerpoint slides as notes in class.

III. Build on What Students Already Know about the Subject • What do the students already know about the

subject?– common sense

• How do they know it?– verify their common sense

• How do you extend their knowledge?– extend their common sense into the uncommon

• Link the new knowledge to the old knowledge


In the example on the “closed universe” earlier, I used this procedure of building on what students already knew (circle and sphere) and extended those ideas into the universe.


Another Example: According to a law of physics, the force of friction does NOT depend on the area of the object. This is counter-intuitive to most students. The law says that the force of friction depends on the two types of surfaces (e.g., wood on wax, wood on wood, wood on concrete) and on the force pressing the two surfaces together (contact force).


Because this law is counter-intuitive, I bring up a case that seems to violate it: wide tires on sports cars. We then investigate the purpose of wide tires. Is it just to make the tire companies more money by allowing them to sell more expensive tires? (Note the humor in this question - part of Principle I.) What about dump trucks - they have wide tires (many tires). Do their wide tires help them go fast?


In this discussion about friction, I use an eraser on the board as a demonstration of friction. Is it “easy” to move the eraser on the board? Is it still “easy” if I press real hard on the eraser? (Is this the idea of a clamp?) Does it get easier or harder if I put the eraser on its side (reduce the area)? I then tell them they will see for themselves this effect in an upcoming lab. Recall that demonstrations were part of Principle I.


• Encouraging practice outside of class allows more time in class for talking to students

• Practice involves using specific algorithmsHow to do this:

– use computer assisted homework programs– use collected homework done with a 7-step

problem solving paradigm– use notes (powerpoint slides with examples)


Computer Assisted HomeworkThe computer assisted homework programs

have been a tremendous help. However, they have taken a lot of time for development.

One of the main advantages of this type of system is the immediate feedback that students get.


Computer Assisted HomeworkA second advantage is the assistance that the

programs provide to the student to aid them in figuring out what they did wrong and how to do the problem correctly.

A third advantage is the fact that the computer can change the problems each time they are run, so the student can continue to practice until the student obtains a perfect score.


Computer Assisted HomeworkA fourth advantage is the fact that the

computer can grade the work, so it saves the instructor grading time.

By giving practice outside of class, the instructor is free to spend more time in class “talking to students”. By removing some of the routine grading, the instructor has more time to further develop the class.


The computer assisted homework is designed to give the student practice and to test to see that the students can in fact do the problem accurately. But there is another important aspect of solving problems, and that is communication.

Collected HomeworkThe primary purpose of the collected

homework (now that the practice aspect has been reduced) is to teach the student how to communicate their solution to others.


Collected Homework

To both aid in the communication process, and to show how experts attack difficult (not trivial or obvious) problems, I ask the students to follow a seven-step problem solving paradigm when submitting their collected homework.


Seven Step Problem-Solving Paradigm1. Do I really want to solve the problem?2. Define the situation3. Define what I’m trying to solve for4. Brainstorm5. Plan the attack6. Execute the plan7. Check to see if the answer is reasonable


Collected Homework

The paradigm does not always proceed from step 1 through step 7 in one pass. Often, you find that in doing one step, you have a better idea about something in a previous step.


Collected HomeworkTwo of the steps deserve special mention here:

Step 2, define the situation, means draw a diagram. This helps the students “see” the situation (Principle I) and it connects with what the student already knows (Principle III).

Step 7, check your answer, also connects with Principle III - verify and extend what the student knows.


• Allow “redo” on homework• Drop a test score and/or allow “redo” on one

testPositives

– allows students to learn from their mistakes– takes away from ability to blame others

Negatives– allows students to procrastinate– adds to grading burden on instructor


Redo’s do take more instructor time. However, the question is this: is it better to have more graded homework problems, or have less graded homework problems but have to do them twice?

My fear, based on my experience, is that many students tend to ignore corrections if they have no immediate (graded) incentive to act on those corrections.

With the computer assisted homework doing the job of practice, I can then have fewer collected homework problems which allows me to implement the “redo” policy.

Five Elements

I hope this presentation has shown how I use the five elements in my courses:

I. Show Enthusiasm and Love of SubjectII. Provide a Framework for the Subject III. Build on What Students Already Know

about the SubjectIV. Provide (Graded) PracticeV. Remove Excuses for Failure

Teaching a Course to Non-Majors Dr. Johnny B. Holmes Dean of the School of Sciences, and Professor...

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