SCEN 102 - 2000 Discussion Section Activities

Discussion Sections for May

May 9 - May 14: The Planet Walk

Objectives:

• Students should gain an appreciation for the immense scale of the Universe.
• Students should understand how this scale affects future solar system exploration endeavors such as sending human beings to Mars.

Assignment: (Novak's and Gillis's sections may do this as an in-class activity; do whatever they tell you). Suppose that you are standing on Mars and looking back at the earth and moon. Draw a picture, or provide some words, which describe what you think the earth and moon will look like. You should describe this in terms of angular scale. If you hold your fist out at arm's length, your fist spans ten degrees on the sky. How big will the earth and the moon be, in comparison with what your fist looks like?

Activities in Discussion Section:

• Students should work in their groups with their drawings or descriptions of the earth and moon as seen from Mars. Students should share their individual drawings with their groups. Depending on the comfort level of the TA and the students, these drawings could be shared with the class as a whole. One possible tactic is to post the drawings anonymously.
• Students should then go outside onto the University campus and walk the planet walk, starting from Jupiter in front of Sharp Lab and then going through the inner solar system. When students are at earth, they should be aware of how big the moon's orbit is in comparison with the earth. Students should then walk to the touchstone for Mars (north of Brown Hall), look back at earth, and visualize how big it is. Consider how much effort it took to send human beings from the surface of the earth to the surface of the Moon, and think about the trip to Mars.

May 2 - May 7: Explaining the Phases of the Moon

Objectives:

• Explore yet another pattern in nature - the pattern of lunar phases
• Use your observations of this pattern to test various possible explanations of why the lunar phases occur
• understand how the process of science works.

Activities in discussion section: Your group will participate in the following scenario.

Your principal has been approached by representatives of the Flat Earth Society who wish you to teach an alternative explanation of the phases of the moon. They believe that the moon is shaped like a flat white disc, and that the phases of the moon result when the white disc rotates. We will call their explanation the flat-moon model. When word gets out of the flat-earthers' claims, another group approaches your principal with their explanation of lunar phases. The contend that the phases of the moon are produced when the moon moves into the earth's shadow. This explanation can be called the eclipse model. These models are both in contrast with the standard textbook explanation, in which the moon's motion around the earth is responsible for the lunar phases. We'll call this the orbiting moon model.

Your principal has asked you, the science curriculum supervisor (or, if you cannot visualize yourself as a school teacher, as a member of the school's parent-teacher association) to respond to the Flat Earthers. Because the flat earthers do not believe in the authority of the Federal Government, your principal insists that your arguments be based on actual observations that anyone can obtain for themselves, such as your lunar log. Your job is to demonstrate, on the basis of your observations, which model is correct.

In discussion section you will:

• first hand in either your lunar log or a record of the moon's phases for the previous month obtained from the internet or any other reliable source. If you are in Shipman's sections you will previously have handed in the lunar log in the big class.
• Assemble in groups and develop a comprehensive set of observations of lunar phases as they depend on time.
• Use white discs, tennis balls, and light sources to demonstrate the various models which explain the moon's motion.
• Each group should develop several arguments which support the orbiting-moon model. These arguments will then be shared with the class as a whole.

Discussion Sections for April

April 19 - April 24: Preparing for the second hour exam

April 25 - May 1: No discussion sections because of the scheduling of the second hour exam on April 27.

April 12 - April 17: Sensible Shopping for Pain Relievers

Overall goal of this assignment: A large part of chemistry is determining what things are made of. This discussion section assignment will apply your ability to determine what things are made of to a task which you will face during your life - determining what pain reliever to buy at the drugstore, when your head hurts and the person who used to make that decision for you (for instance, one of your parents) is unavailable. You will see how your ability to identify the contents of a pain reliever will help you make more intelligent purchasing decisions.

Discussion Section Assignment: Bring in an advertisement for a pain reliever like aspirin, advil™, or tylenol™. It should be a print advertisement, which contains at least two claims about the product. These claims need not be claims which are testable. You should hand in a brief written assignment in which you verify the claims and state whether these claims are useful in providing information. You will discuss these claims in your group.

SAMPLE ASSIGNMENT AND ANSWERS: The April 18, 2000 issue of Woman's Day containd an ad for Motrin IB which provided the following information:

"Moms are 73% friendlier to alien invaders when they don't have a sinus headache. Motrin IB™ is combined with a powerful decongestant so you can get to your sinus pain and pressure before it gets to you. Good thing. This is no time to space out. For a free sample, call 1-877-224-6612. Life is too good to feel bad."

Claim #1: "Moms are 73% friendlier to alien invaders when they don't have a sinus headache." It would be hard to test this claim using real alien invaders since, even if you accept the idea that alien invaders exist (more about that later in the course), devising a controlled experiment where mothers face alien invaders would be hard. The picture shows a mother confronting a child who is dressed up as an alien invader. But in any event, the claim does not help you make a purchasing decision. Of course you feel lousy when you had a sinus headache.

Claim #2: While it is not stated directly in the ad, it is clearly implied that Motrin IB™ has some special ability to deal with sinus headaches. The active ingredient in Motrin™, found by looking at its label, is Ibuprofen, one of the three most common types of pain reliever. This ingredient can also be found in Advil™ as well as in generic products such as Happy Harry's Ibuprofen. (For non-Delawareans who have not explored our retail market, Happy Harry's is the name of a statewide drugstore chain, and the Harry referred to in the name is Harry Levin, the founder of the chain, not Harry Shipman, your course instructor.) As I write this I don't know what the decongestant in Motrin IB™ is, but I'm sure it is a decongestant which you can also buy separately. You can test this claim yourself by looking at the label of some other products. You can find that a generic ibuprofen-based pain reliever, combined with your choice of decongestant, can accomplish the same thing as Motrin IB™ can.

Knowing what's behind the two claims does not necessarily mean that purchasing Motrin IB™ is the wrong decision. You may prefer to take one pill instead of two. You may find that the appearance or feel of the pills in the generic products is not to your liking. (I have been told that it is very difficult to sell a pill in the Japanese market unless the pill really looks perfect.) You may accept the arguments of the drug manufacturers that generic products are somehow "inferior." I've never understood these arguments against generics - two tablets which list the same active ingredient should have the same effect on you, unless you have some unusual problem with one of the inactive ingredients.

Learning Objectives:

• Students should be able to distinguish between claims that provide useful information about a product and useless claims - claims that do not help you make an intelligent purchasing decision. and unverifiable claims in advertisements. Some useless claims -- like Claim #1 in the Motrin ad -- are simply baloney, puffery, or BS. (If I were to spell out what BS means in this webpage, it might not get past some screening programs which are designed to keep inappropriate web pages from some places.) Other useless claims may be verifiable - 9 out of 10 doctors may prescribe aspirin for something - but that does not tell you to buy one brand of aspirin instead of another.
• Students should know the difference between active and inactive ingredients on a label, and be able to identify the more commonly used active ingredients in pain relievers.
• Students should know how they can use publicly available information on pain reliever bottles in order to make a rationally informed decision about which pain reliever they should buy. (Note that there is no one best answer to the question, "what pain reliever should I buy?)
• Students should be able to calculate the cost-effectiveness of different brands of pain relievers.

Student Activities in Discussion Section:

• Identifying Claims: Students should share the advertisements that they have brought into class as a group. Each group should come up with a list of claims which are useful or useless. These claims should be shared with the class as a whole, and the class should assemble a list of claims which can be investigated by reading labels on pain reliever bottles.
• Analyzing labels: Each group will be given a list of labels for various pain relievers. Groups should identify active ingredients and inactive ingredients. If there are claims which can be investigated using the information which is available to you, investigate those claims and determine whether they are helpful or not helpful to making a purchasing decision.
• Cost analysis: Each label not only lists the active ingredient, but also shows how much of the ingredient is in each tablet, how many tablets are in the bottle, and what the cost of the bottle is. Each group should determine the cost per gram of the pain relievers for the bottles that they have.
• Sharing of the cost analysis: Different groups are analyzing different pain relievers. The groups should post the cost per gram on the blackboard and then make appropriate conclusions about sensible shopping decisions.

This activity was adapted from similar activities found in commercially available texts (see, for example, Parker, McLoughlin, and Tanenbaum, Strong Medicine: Chemistry at the Pharmacy, Middletown, Ohio: Terrific Science Press, 1995, pp. 83-86; S. Tocci, Chemistry Around You: Experiments and Projects with Everyday Products, New York: Arco, 1985, pp. 75-82). The adaptation was presented to the 14^th Biennial Conference on Chemical Education, Clemson, SC by Valerie Bergeron (Delaware Technical and Community College) and Harry Shipman, in an effort supported by the National Science Foundation and the Partners for Terrific Science Programs of Miami University, Middletown, Ohio.

April 5 - April 10: The Patterns, Rules, and "Laws" of Magnetism

Learning Objectives:

• Students should learn how to use evidence to formulate a scientific law.
• Students should be able to explain the relationship between the law and the evidence that supports it.
• Students should understand that scientific laws are different from laws in the legal process.
• Students should understand what objects are attracted to magnets and what objects are not attracted to magnets.

Student Activities in Discussion Section:

• Experimenting: Students, working in groups, will explore their surroundings in the room, using their magnets to test various substances in the room, in their pockets, and in other places. (As long as one can test jewelry without invading someone else's personal space, testing jewelry, glasses frames, and other objects is certainly OK.) The only objects which should not be tested are credit cards, UD#1 cards, and other such objects.
• Recording and reporting:Groups of students should record their data in a table, and put the table on a form which is suitable for display. At the options of the TA (and depending on the characteristics of the classroom) this could be on a large piece of butcher paper, overhead transparencies, or the blackboard.
• Explaining and classifying: Students, first working as individuals and then in their groups, should examine the publicly available data and attempt to think inductively to develop a "law of magnetism." This law, like most other scientific laws, should describe the patterns which are seen in the data, or information, which is determined from experiment or observation. A law which simply comes from a textbook is not what is wanted from this classroom activity.
• Communicating (sharing explanations): Groups should report out to the class as a whole, posting their laws in a publicly available place.
• Comparing explanations: If there is time, all groups should report their laws and then individual groups should determine the ways in which the publicly available data support the laws. If there is not time to do this, each group, when it describes its law, should mention one piece of evidence which supports their law.
• Extensions of this activity: Also if there is time, the TA may point out that a different sort of exercise, one where the chemical elements which are present in the materials being tested are known, could be used to formulate a more specific law of magnetism.

This activity has been around for quite a long time, but there are different ways of teaching it. For it to be successful, it has to be taught in an inquiry mode, where students develop the patterns themselves, where students devise their own ways of organizing the data, and where students are given supportive, constructive criticisms of incorrect answers. I was exposed to this activity, and this kind of pedagogy, when I visited a class taught by Professor Tom Koballa of the Science Education Department of the University of Georgia.