AN ACTION RESEARCH PROJECT

RESULTS and APPENDIXES

The National Science Education Standards (NSES) Physical Science Content Standard B (Grades 9 – 12) states that every student should develop and understanding that:

The action research project that follows includes:

• alternative conceptions held by my high school physics students regarding aspects of the above key science concepts
• strategies (learning cycles) for overcoming those alternative conceptions
• the results of having implemented those strategies
• an analysis of the results in terms of how effective the strategies were in helping students overcome their alternative conceptions

[Back to Table of Contents]

INTERVIEW FORMAT. Ten seniors – six boys and four girls – of varying academic levels were interviewed individually to identify their alternative conceptions (a strategy suggested in Sunal, 2000). They were asked five questions orally, three of which included prompts. I (the instructor) recorded the answers they gave. Below are the questions asked and sample student responses (see Appendix A for sample student responses)

(QUESTION 1) If a student touches ice with her finger, why does she feel cold?

SECOND SCENARIO. Students were given the following prompt: A student holds an iron bar to a fire. After a little while his hand feels hot.

(QUESTION 2) How come his hand feels hot when he touches the fire?

THIRD SCENARIO. Students were given the following prompt: A student holds an identical iron bar to a piece of ice. After a little while his hand feels cold.

(QUESTION 3) How come his hand feels cold when he touches the ice?

FIFTH SCENARIO. Students were given the following prompt: Air conditioners have a part/unit on the outside of a room and a part/unit on the inside of a room.

As a result of the interviews (see Appendix A for sample student responses), I discovered two alternative conceptions that my seniors had regarding heat:

When I asked them why their finger feels cold when they touch a piece of ice, all but one responded "by the book"; they said that heat leaves their finger and goes to the ice (and not that the ice transfers cold to their finger). Several students even explained that their fingers felt cold because objects at a higher temperature release heat until they reach equilibrium with their surroundings. One explained that as the heat transferred, the finger's temperature went down and hence the finger got cold. I asked one of these students where they learned all this and they said last year in Chemistry. The one student that answered incorrectly assumed that the ice transferred cold energy to his finger.

As I expanded my inquiry a little though, I discovered that the "by the book" answers students gave were a little too canned. This became evident in the responses given by students to the THIRD SCENARIO: A student holds an identical iron bar to a piece of ice. After a little while his hand feels cold. How come he feels cold?

As expected, all ten students knew that the heat transfer process was from the fire to the hand through the bar in the SECOND SCENARIO: A student holds an iron bar to a fire. After a little while his hand feels hot. How come his hand feels hot when he touches the fire? Only five, however, were not deceived by the deceptively similar prompt of the THIRD SCENARIO and answered QUESTION 3 correctly. These students realized that the heat transfer process when a student holds an iron bar to a piece of ice is the same as when he touches the ice directly (as in the FIRST SCENARIO) and correctly said that the bar transfers heat from the hand to the ice. The other five gave essentially two kinds of responses: three said that the ice transferred cold/heat energy/its temperature to the bar and then to the hand (regressing to a pre-chemistry conception of heat), and two said that no energy is transferred at all. *

It seems that the prompt given in the THIRD SCENARIO was enough to send a "ripple" through students’ smug conceptions of heat transfer. Instead of adapting their schemas to handle the new situation, many opted to regress back to a "safe place", a primitive notion of heat transfer.

Then I raised the difficulty level up a notch and asked the seniors a related question: how does an air conditioner or refrigerator work to cool the air in a room or a freezer compartment. One student gave a clinical explanation of how the air conditioner

• As a side note, one of the students that answered incorrectly suspected his explanation was erroneous but that nevertheless he would find out the "right way of thinking about it" soon since we were about "to study this stuff in class." This kind of response reflects the all too common tendency among my students to wait to be told how to think instead of grappling with the idea themselves and coming to their own conclusions.

contains a fluid that extracts heat from the air in the room/compartment. Another mentioned that the AC/refrigerator contains a gas that cools the air. Four students said

that the AC/refrigerator absorbs/filters the air, thereby taking away the heat from it. The others gave various erroneous versions of the "magic box" explanation: the AC/refrigerator magically "cools" the air; three said that the AC produces/makes cool air (in the sense of manufacturing); one said that that the AC converts the electrical energy into thermal energy (no doubt deriving his explanation from our main theme in Physics this year: Conservation of Energy and energy transformations). Again, there was a notable confusion as to what cooling is: withdrawing heat or adding cold.

In the FOURTH SCENARIO, I prompted students with a reminder that air conditioners have two components: a part inside the room and a part outside regardless of whether they are wall mounted or split units. Seven students said that the air conditioner extracts the warm air from the room and brought new air in (two reasoned that this was true because if you stand outside next to an AC you feel hot air blown from the back; they failed to realize that the heat was being ejected from the room not the air). One student said that the air conditioner just takes the warm air out but doesn't bring new air in (not realizing that if this were true the room would become evacuated of air). One student said that it is the same air that is in the room before and after but did not justify why. Only one could justify why it was illogical that air be brought in from the outside since the air outside was even hotter than the air inside.

IMPLICATIONS FOR THE CLASSROOM

Student responses clearly show that they have a conceptual discrepancy about the nature of heat itself. They fail to realize that heat is energy in motion between two objects at different temperatures and that it always travels from the hotter object to the cooler one (unless external work is done). Many seem to think that the energy is indivisible from the object that contains the energy and therefore the objects (in the case of the AC or refrigerator, the air) must move physically from one place to another (from inside the room/compartment to outside) instead of the energy moving. Because of their misunderstanding of the nature of heat, they believe that cold flows and even that cold matter exists.

Students need to be confronted with carefully concocted discrepant events that throw pebbles into their otherwise placid pictures of the world. These tailor–made discrepant events will specifically show students the inadequacy of the concept that things are inherently hot or cold, and that cold is a substance in and of its own, separate from heat. A variety of instructional activities including analogies, classification, and directed classroom discussion will be used to make conceptual bridges (Sunal, 2000) between students’ experiences and explanations of those experiences.

Key Question (to introduce Discrepant Event): Why do Eskimos build houses out of ice to keep warm. Since heat goes from hot to cold, don’t the ice walls take away the warmth inside the house?

OBJECTIVES: Students will be able to:

MATERIALS:

1. Pose key question to class; put up OVERHEAD

2. Group students in dyads. Have them take one sample each of the different materials and develop a simple test for conductivity. A simple test could be to close the eyes and feel each of the items at room temperature. If the item feels cold, it is a good conductor; if it feels normal, it is not. Good conductors rob the heat away from our body leaving a heat vacuum (a.k.a. cold).

3. Have dyads rank the items in order of conductivity.

4. Have dyads compare results in the classroom scientific community to see if they agreed upon the ranking and to share the variety of tests (if any) they devised to test conductivity.

          14. Evaluation: Cooperative work observed and recorded in rubric (see Appendix B), Written explanations of the double-paned                     window turned in by groups.

LEARNING CYCLE 2: SECOND LAW OF THERMODYNAMICS

Key Question (to introduce Discrepant Event): How could you build a heat engine that is 100% efficient if you manage to get rid of the friction and insulate it perfectly from the outside environment?

11. Uncover Second Clue: Take a look at a magnification of the turbine part of the steam turbine. What would have to be different in order for this to be a 100% efficient heat engine? Ans. There couldn’t be any gas (even if it is low–pressure gas), on the back sides of the turbine blades. This gas impedes the turbine, even if it is frictionless, from turning. In addition, the high pressure steam entering is not discriminatory. Design can improve the amount of steam that pushes the leading turbine blade forward, but there will still be some steam that pushes on the front of the next blade, counteracting the turbine’s forward progress.

OVERHEAD: disguised formula and formula for Carnot efficiencyCooperative Work Rubric

OVERHEAD: Student explanation

16. Put up OVERHEAD: show disguised formula for Carnot efficiency (cover up real formula):



17. Ask dyads the following question: looking at the formula from a mathematical standpoint, how could you modify your value for x to make E increase? How could you modify your value for y to make E increase? Ans. increase value of x or decrease the value of y.

18. OVERHEAD: now uncover the second half of the OVERHEAD and reveal the formula for Carnot efficiency:



Ask dyads the following three questions:

a. Would the efficiency of a car increase or decrease on a cold day? Explain. Ans. A variety of answers might result but the important point that students must grasp is that differences in ambient temperature primarily affect the exhaust system (heat sink), not the engine itself. The heat reservoir runs very hot on hot or cold days (it is insulated by thick metal and a water jacket, the cooling system). The exhaust system is not insulated from the environment except by the thin metal of the exhaust pipe. If the heat sink is cooled, the efficiency increases and if the heat sink is heated, the efficiency decreases, assuming that the temperature of the heat reservoir is more or less constant.

b. Would the efficiency of a car increase or decrease on a hot day? Explain. Ans. Ditto the above.

19. After they answer, have dyads put down their writing utensils and share their conclusions orally. Then they will pass their conclusions in and the answers will be critiqued orally.

20. Launch final question to dyads: Which increases the efficiency more, heat the heat reservoir by T degrees or cooling the heat sink by T degrees, or is the increase in efficiency the same? Ans. it turns out that lowering the heat sink’s temperature by T degrees is more effective than raising the heat reservoir’s temperature by T degrees.

EX: Assume the initial conditions are as follows: heat reservoir = 400 K, heat sink = 300 K

Eff. = (400 – 300)/400 = 0.25 = 25%

If we change the heat reservoir’s temperature to 500 (add 100 degrees):

Eff. = (500 – 300)/500 = 0.40 = 40% …the efficiency goes up 15%

If we change the heat sink’s temperature to 200 (subtract 100 degrees)

Eff. = (400 – 200)/400 = 0.50 = 50% …the efficiency goes up 25%

Bonus question: Why? Ans. Mathematically speaking, adding a hundred more and then dividing by 100 more is not the same as subtracting a hundred and dividing by the same divisor. Dividing by a hundred more has a large impact on the resulting quotient than subtracting 100 from the dividend.

21. Evaluation: Cooperative work observed and recorded in rubric, debunk completed and turned in.

[Back to Table of Contents]

LEARNING CYCLE 3: APPLYING THE FIRST LAW OF THERMODYNAMICS

Key Question (to introduce Discrepant Event): A refrigerator is running in the middle of a classroom at room temperature. What would happen to the temperature in the room if the door of the refrigerator were left open?

•                 explain correctly that heat is transferred away from substances to cool them and that it must be accounted for as with all forms of energy
•              explain correctly that heat naturally transfers from hot to cold unless external work is done.

familiarity with the concepts of WORK and ENERGY

working knowledge of the LAW of CONSERVATION OF ENERGY

knowledge of how to write a correct hypothesis

familiarity with basic design of HEAT ENGINES (HEAT PUMPS)

OBJECTIVES: Students will be able to:

• predict what will happen to the temperature in a room when the door of a refrigerator in the room is left open
• form testable hypotheses about why the temperature changes/stays the same in a room in which a refrigerator is running with the door open
• work effectively in a dyad
• dissect a cooler into its main components by function

MATERIALS:

1. Pose key question to class; put up OVERHEAD

2. Have students individually predict the result and then hypothesize why (in writing). Ans. the temperature of the room will go up slightly due to the overheating of the refrigerator motor. The refrigerator motor is built to cool the insulated compartment inside the refrigerator (heat sink) by removing the heat from it and putting it into the heat reservoir (the outside world). If the refrigerator door is left over, it is a much greater feat to remove the heat since the entire room becomes the compartment. This feat is made especially difficult since the heat sink is now the entire room and the heat reservoir, the entire house or outside environment.

3. Divide students into groups of three or four. Have them share their individual conclusions and then come up with at least two testable hypotheses and write them on their poster paper in large readable type (posters should be legible from any chair in the classroom).

4. Have groups draw a cross section of a cooler with every component part it needs to do its job properly and the function of each part. Give students a minimum number of parts (say five) to force them to stretch their schemas.

5. Put up OVERHEAD: Ask groups to compare and contrast a cooler with a refrigerator. How are they alike and how are they different (again, have them list at least five similarities and differences to stretch their schemas). Ans. the cooler and the refrigerator both have isolated insulated compartments. Both cool the temperature inside the compartments. 

EVALUATION: Cooperative work observed and recorded using rubric, drawings completed and turned in, comparison/contrast completed and turned in.

INVENTION PHASE

OBJECTIVES: Students will be able to:

• recognize a refrigerator as a heat pump in reverse
• describe the operation of a simple manual heat pump working in reverse
• define the process of heat transfer from a heat sink to a heat reservoir as another manifestation of WORK
• share their results orally and in written form with a scientific communities

MATERIALS: copies of unlabeled heat pump diagram

Cooperative Work Rubric

7. Have groups explain on their posters what would have to be done to keep the contents of a cooler cool if the cooler's lid were open. Assume that you have only a finite amount of ice. Ans. Ice would have to be added periodically. The melted ice would have to be extracted and refrozen. A cycle would have to occur.

8. Define the action of keeping the cooler's contents cool as WORK.

9. Give students a drawing of a simple heat pump diagram with no labeled parts and have students label the parts and show the direction of heat flow in the refrigerator.

10. Articulate for students that a cooler/refrigerator is a simple HEAT PUMP in reverse (removing heat from the heat sink and transferring it to the heat reservoir (the environment).

11. Have groups revisit their hypotheses and decide if any changes should be made. If they will change their hypothesis, they should not cross out their old hypotheses. They should just write their new hypotheses below.

12. Closure: Collect and hang up the posters around the room. Open up the class for discussion about the results and the hypotheses and debrief about how the hypotheses evolved as new information was presented.

13. Evaluation: Labeled Heat Pumps completed and turned in, Cooperative work observed and recorded using rubric.

OBJECTIVES: Students will be able to

• Class set of envelopes with cut outs of refrigerator (or cooler) parts, Cooperative Work Rubric

OVERHEAD: Student explanation

14. Have students, in their dyads, explain what would happen to room temperature if the refrigerator were placed in a cold room and the door was left open. Ans.

15. Put up OVERHEAD: Have students, in their dyads, debunk the following student explanation: An air conditioner throws the warm air in a room outside. That is why the air conditioner feels warm outside and that’s why air conditioners have a part inside the room and a part outside (like a split unit). I can’t understand where a cooler throws the heat if it is perfectly insulated from the outside environment? Ans. First of all, an air conditioner does not throw the air outside; it throws out the heat the air contains. The reason the outside of an air conditioner feels warm is because the heat is being released in the condensation process. A cooler does not throw the heat out as the refrigerator does. This is one of the main differences between the cooler and the refrigerator. The refrigerator extracts the heat from the objects inside it and throws it out. The cooler uses ice to extract the heat from the objects but since the ice is inside the insulated cooler, the final temperature of the objects will warm than the ice.

16. Evaluation: Cooperative work observed and recorded in rubric, debunk completed and turned in.

Key Question: If I am sweating, why do I feel cool when a fan blows on my skin?

EXPLORATION PHASE:

OBJECTIVES: Students will be able to:

cologne/perfume

rubbing alcohol or ether

piece of cardboard (for fan)

source of water

block of cork

piece of tinfoil shaped into a small dish

1. ACTIVITY: Pour some cologne/perfume onto the back of each student's hand. Students' hands will feel cold.

2. Pose key question to class; put up OVERHEAD

3. Have students individually form and write hypotheses as to why their hands feel cold when cologne/perfume is put on them. A possible misconception students might have (from a prior learning cycle in this class, actually) is that since good conductors quickly rob heat away from objects they are in contact with, then alcohol must be a good heat conductor and robs the heat away from your hand leaving a "heat vacuum". Teacher should walk around the room and get a feel for the individual prior knowledge before grouping students.

4. . Pass out grading rubrics and go over so students know what they will be evaluated on before going any further. This is also a way of repeating the directions of the tasks (for ESL) reasons: once going over the rubric orally, once when the activity is introduced, and of course, the students will have the rubric present at all times to refer to.

5. DRAMATIC DEMO: Put some water on a large cork and set a watch crystal or a piece of tinfoil shaped into a small dish on it. Into this dish pour a little alcohol or ether (keep away from open flames) and make it evaporate rapidly by vigorous fanning. Enough heat will be carried away to turn the water into snow, or even to freeze the dish firmly to the cork (Freeman, 1965).

6. Group students into triads and have them share their hypotheses. Students will critique each others' hypotheses and their own after having seen the demo (especially the fanning part) to see what modifications should be made based on this new information gathered. Require triads to record the reasons why modifications were made to the hypotheses and whether it was based on what they saw in the demo or was a product of their discussion. The triads will then write two conditional statements each to verify the hypotheses they have left.

EX: If Hypotheses A is true,

and – – – – – – – – – – – –

then such and such must occur or also be true.

7. EVALUATION: Degree of completion and quality of tasks and degree of cooperation in collaborative groups using rubric

8. Put up large-type posters on the board with ingredients of cologne/perfume, a table of volatility of liquids, and a definition of volatility. These are clues.

9. Break up the students into dyads now. Let them process the clues given for five to ten minutes. Circulate to assess group work and to ask convergent questions to inch groups along.

10. Use the following analogy and a question as a further clue into the causes of cooling: A riot occurs at a soccer stadium. The riot police are desperately trying to keep the fans from entering the soccer field.

What fans are more likely to get in? The more riotous fans and the fans that are at the front of the crowd. (molecules with higher avg. kinetic energy)

Are the more riotous fans, the ring leaders, the ones at the front? Yes.

What is a strategy that a riot police chief might try to cool off the crowd? Get rid of some of the more riotous elements. Oh, you mean make them vanish? Yes. (evaporation)

Make them vanish...OK. Now how is this analogy explain how the cooling occurs when cologne is put on your hand…or…when you walk in front of a fan all sweaty and you feel cold?

11. Students will grapple with the analogy at different levels. Some, already knowing that the cause of the phenomenon is evaporation, will be occupied trying to correlate each part of the analogy with evaporation. Others will simply be trying to make sense of the analogy clue given. Teacher will circulate to help each group out wherever they are. Groups will put in writing their final hypotheses and an explanation of the analogy. If a group finishes this part early, they can go on ahead to the EXPLORATION stage.

12. Once all groups or most of them get it, give out this info: Evaporation of perspiration from the skin is an effective way of cooling the body. Over two million joules of thermal energy are carried away for each liter of liquid evaporated (Freeman, 1965). This will be just interesting information for the groups that already figured it out and will be a final clue to the group(s) still grappling.

13. EVALUATION: Degree of completion and quality of tasks and degree of cooperation in collaborative groups using rubric

OBJECTIVES: Students will be able to

large poster paper for group designs

markers

OVERHEAD: Student conclusion about condensation

OVERHEAD: Design-your-own-cooling system

14. Have dyads react in writing to the following student conclusion: Since evaporation is a cooling process, condensation, the opposite of evaporation, must be a warming process. Ans. Actually, it is. When you emerge from a shower and step into a dry room, you are likely to feel chilly. This is because evaporation is taking place quickly. If you stay in the shower stall, even with the water off, you do not feel as chilly. This is because when you are in a moist environment, moisture from the air condenses on your skin. This produces a warming effect that counteracts the cooling effect of evaporation (Hewitt, 1992)

15. Put up OVERHEAD: ADVERTISEMENT: For $30,000 a business/warehouse in the U. S. can have their roof equipped with an effective energy-saving cooling system based on the principle of evaporation we have just discussed (give Internet site: www.sprinkool.com to lend legitimacy to this). One company claim that a temperature reduction of 10° is possible. Group dyads together (into fours) and have them come up with the basic design for such a system on poster paper.

EX:

16. Give a personal anecdote about Amir, my brother, who is trying to do just this in Panama to save businesses and other buildings with tin roofs money on their cooling bills (since they will be able to do without expensive AC on all but the hottest days). Draw his basic design on the board for students.

17. EVALUATION: Degree of completion and quality of tasks and degree of cooperation in collaborative groups using rubric

[Back to Table of Contents]

Key Question: Why is water used in automobile engines for cooling if water has a high specific heat and would therefore not take away heat from the engine as fast as a substance with low specific heat?

skill of how to write a correct and testable hypothesis

• knowledge of the concept of specific heat and the specific heat of water

• familiarity with the basic concepts of evaporation and condensation

• familiarity with the concept of thermal conductivity

OBJECTIVES: Students will be able to:

• form hypotheses about why water is a better cooling agent in car than alcohol even though water has a higher specific heat
• identify a common misconception that many people have about cooling
• revise a hypotheses based on new data obtained

MATERIALS: OVERHEAD: with Key Question

OVERHEAD: Rap sheet on alcohol and water

1. ORAL DISCUSSION: Ask students to individually hypothesize in writing between using alcohol and water as a cooling agent. Most will pick alcohol. Ask students to justify their reasoning. Some, from previous learning cycles, will correctly indicate that water has a high specific heat and will resist receiving heat from the object it is supposed to cool. Alcohol will quickly rob the heat away from the object being cooled.

2. Pose key question (discrepant event) to class; put up OVERHEAD: Why is water used in automobile engines for cooling if water has a high specific heat and would therefore not take away heat from the engine as fast as a substance with low specific heat? Ans. Water is used because it is plentiful, inexpensive, and doesn’t boil quickly due to its high specific heat. In order for a coolant to be effective in a re–circulating system, it needs to be in liquid form. The coolant takes the heat from the hot place and deposits it in a cooler place. The coolant can do this as long as it is in liquid form. Even during the change of state from liquid to gas, the coolant can take away a lot of heat from the engine for its vaporization, but once it is a gas, it is almost useless as a coolant for two reasons: it doesn’t circulate, it has an even higher specific heat than when it was in liquid form.

3. Put up OVERHEAD: Rap sheet about alcohol and water. The following information will be included: freezing and boiling points of alcohol and water, specific heat of water in liquid and gas state, specific heat of alcohol in liquid and gas states, thermal conductivities of water and alcohol in liquid and gas states, densities of water and alcohol in liquid and gas states, heat of vaporization of water and alcohol, volatility of water and alcohol, cost per liter of commercial water and alcohol, and some other but irrelevant info about water and alcohol (all data obtainable from the CRC Handbook of Chemistry and Physics with the exception of the cost which can be obtained locally).

4. Have students write down revise (in writing now) their hypotheses as to why water might be used instead of alcohol based on the new rap sheet information. Require students to cite why their hypotheses changed or were confirmed.

5. EVALUATION: Written hypotheses completed and revised successfully

INVENTION PHASE

OBJECTIVES: Students will be able to:

OVERHEAD: with Key Question

OVERHEAD: simple radiator with ice, water, and steam

6. Group students into triads and have them share their hypotheses. Students will critique each others' hypotheses and their own. Triads will revise and decide upon one common hypothesis.

7. Triads will share their hypotheses with the class (scientific community).

8. Put up OVERHEAD: Simple radiator with ice, water, steam in it.

• Ask the question: If this is a closed system, which is the more effective cooler and why? Ans. The ice won’t circulate so it is not the best. The steam won’t circulate as well as the water and will not take away as much heat as the water will (thermal conductivity).

9. Put up OVERHEAD with Key Question again. Have students individually answer the Key Question now with their new information.

10. EVALUATION: Degree of completion and quality of tasks and degree of cooperation in collaborative groups using rubric

EXPANSION PHASE:

OBJECTIVES: Students will be able to

OVERHEAD: Multiple–choice question on coolant

11. Dyads will answer the following multiple–choice question and explain what specifically could (and does) happen to an engine if the coolant is not added, in writing:

In places where there are extremes of temperature, hot and/or cold, a chemical coolant (sometimes called Anti–freeze) is often added to the water in the radiator. The purpose of this coolant is to:

a. lower the boiling point and raise the freezing point of the cooling solution

b. raise the boiling point and lower the freezing point of the cooling solution

c. lower the boiling point and lower the freezing point of the cooling solution

d. raise the boiling point and raise the freezing point of the cooling solution

12. Teacher collects all the answers and reads them out loud to the class one at a time with no "color" commentary (names of authors omitted). Students listen and take notes.

13. Dyads will get their explanations back and revise their explanations as they see fit after hearing the hypotheses of the scientific community. The revisions should be written after the original explanations. The originals should be left intact and not be erased or modified. Ans. Anti–freeze raises the boiling point to prevent evaporation and lowers the freezing point to prevent freezing. Freezing (partial or complete) would prevent the free flow of coolant through the various parts of the engine and could obstruct the transfer of heat to the outside environment. Some parts of the engine might get hotter than others. But more importantly, the reduction of the freezing point is important since water expands when it freezes and could crack the engine block or exert undue pressure on it as it expands.

14. Collect work.

15. EVALUATION: Degree of completion and quality of written tasks turned in.

[Back to Table of Contents]

1– Freeman, I. M. (1965). Physics Made Simple. Garden City: Doubleday & Company, Inc., p. 76–79

2– Halliday, D., Resnick, R., & Walker, J. (1993). Fundamentals of Physics. New York: John Wiley & Sons, Inc., p.

3– Hewitt, P. (1992). Conceptual Physics. Menlo Park: Addison–Wesley, p. 330–334, 353–355.

4– National Science Education Standards (1996). Washington D. C.: National Academy Press, p. 180.

5– Sunal, D. M. & Sunal, C. S. Science in the Elementary and Middle School (2000). Tuscaloosa: the University of Alabama, p. 12–6 – p. 12–12.

6– Thermal Conductivity of Common Materials (1974). CRC Handbook of Chemistry & Physics. Cleveland: CRC Press, Inc.

RESULTS and APPENDIXES

Following are samples of answers given in the student interviews conducted before the implementation of the science module on Thermodynamics.

• SECOND SCENARIO. Students were given the following prompt: A student holds an iron bar to a fire. After a little while his hand feels hot.

…and then were asked the following question:

(QUESTION 2) How come his hand feels hot when he touches the fire?

• THIRD SCENARIO. Students were given the following prompt: A student holds an identical iron bar to a piece of ice. After a little while his hand feels cold.

...and then were asked the following question:

(QUESTION 3) How come his hand feels cold when he touches the ice?

Sample student answers to QUESTION 3

FOURTH SCENARIO. Students were asked the following question:

(QUESTION 4) How does an AC/refrigerator work to cool a room/compartment?

Sample student answers

FIFTH SCENARIO. Students were given the following prompt: Air conditioners have a part/unit on the outside of a room and a part/unit on the inside of a room.

Following are the grading rubrics used for work in cooperative groups/dyads.

Following are all correspondence sent and received concerning the action research project.

TOPIC APPROVAL

Dennis Sunal
Alabama Science Teaching and Learning Center
The University of Alabama, Tuscaloosa AL 35487 USA
Fax 205-348-6782
Roll Tide


The conceptual discrepancy that students have that I would like to do my action research project on is:

Cold is a quantity much as heat is a quantity Students don’t realize that cold is simply the absence of heat and that cold objects simply have low internal energy because heat has been removed from them and a "heat vacuum," so to speak, has resulted. A common manifestation of this conceptual discrepancy is a student’s explanation that upon touching a piece of ice, his finger gets cold because the ice transfers "cold" to his finger when, in fact, his finger is transferring heat to the ice, thereby leaving a "heat-free" zone on his fingertip. If students are asked to explain why their hand gets hot when they hold a bar of iron to a flame, they will correctly respond that the fire heats the bar and the bar heats their hand. And if asked to explain why their hand gets cold if they hold an iron bar to a piece of ice, they will also assert that the ice cools the bar and the bar cools our hand. But when asked to identify what is flowing and when asked to draw an arrow showing the direction of flow they will identify "cold" and will draw the arrow going from the ice to the hand and not from the hand to the ice.

At a more sophisticated level, the conceptual discrepancy that cold is a quantity much like heat appears in students’ explanations of how air conditioners and refrigerators work; they falsely presume that air conditioners and refrigerators add cold to the air inside them instead of extracting the heat from the air.

A discrepant event that could provide students with an experience that confronts their conceptual discrepancy would be the difference they would feel (on their face, for example) between:

1. opening the door of an automobile that has been sitting in the sun the whole day (burst of hot air)

2. opening the door of a car in the shade that has had the air conditioner running the whole time (no burst)

Or, better yet, the difference between what the student feels when he opens the car door of the vehicle that has been in the hot sun (burst of hot air coming towards him) and what he feels when is sitting in an air-conditioned car and the car door is opened to the hot ambient temperature (also, a burst of hot air coming towards him).

Or they can grab a flask with boiling water in it and compare it to grabbing the glass bulb that contains a liquid with an extremely low boiling point, etc., etc.

From:	"Dennis Sunal Sunal" <dwsunal@hotmail.com> Save Address - Block Sender
To:	russbecca@hotmail.com Save Address
Subject:	Re: idea for conceptual discrepancy
Date:	Wed, 22 Mar 2000 16:21:37 CST

Reply

Reply All

Forward

Delete

Previous

Next

Close

There is a problem here in students thinking. So, a good area to explore. This topic, heat, will be covered in your class in April? There are othe rconfusing aspects for students. Heat and cold are two seperate ideas is built into English and all European languages. Also, heat is confused in heat transfer. Take, touching metal and touching wool in the same room.


See you Staurday!


Dennis Sunal

FIRST CONTACT WITH MENTOR

rom:	kardenas@att.net Save Address - Block Sender
To:	russbecca@hotmail.com Save Address
Subject:	CSE 564
Date:	Mon, 06 Mar 2000 16:52:01 +0000

Reply

Reply All

Forward

Delete

Previous

Next

Close

Hello Russell:

I just wanted to say hello and let you know that I am going to enjoy working with you on the Action Research Project this semester.  Please think about your needs and we will communicate soon.  Feel free to contact me anytime.  Thank you.

 

SECOND CONTACT WITH MENTOR

Hello Kimberly:

My name is Russell Krummell and I am your lowly and humble disciple (or something like that) for Dr. Dennis Sunal's CSE 565 course here in Asunción, Paraguay. Just wanted to say Hi, let you know where I am in cyberspace, and share some info with you regarding the action research project I (or we've) been assigned. Contact me either at:

Krummell@mmail.com.py or russbecca@hotmail.com

I've been thinking about what material I will be covering in my senior level Physics class come April (that is the time period during which we are supposed to conduct our splendid little project). I will be heavy into thermodynamics by then and recall a classic conceptual discrepancy students have regarding cold. Many people think that cold is a quantity in much the same way that heat is (when in fact it is the absence of heat).

to investigate, I was thinking of several questions I could pose to students in the interviews I will conduct such as why does your finger get cold when you touch metal or how an icebox (or refrigerator) works, how ice cools a drink, or why you feel cold when a fan blows on your sweaty skin after you exercise.

Anyhoo. I hope that is a bite–ful to chew on for a little while.

Talk to you later,

Russell

THIRD CONTACT WITH MENTOR

Hi Kimberley:

I haven't had time to read your e-mail that you sent to my krummell@mmail.com.py address. I'm going to ask that you send all correspondence to my russbecca@hotmail.com so that I can access it from wherever I am. Thanks!

I will read your last message ASAP and hope that what I am sending now is not redundant or irrelevant because of YOUR message. This is supposed to be a conversation after all!

 did the interviews with my kids and found out that the kids aren't as ignorant about the topic as I thought (somewhat to my chagrin initially, I thought that I had found a MAJOR conceptual discrepancy…I know I should be happy that my students are more advanced than I expect).

I interviewed ten students. When I asked them why their finger feels cold when they touch a piece of ice, all but one responded "by the book"; they said that heat leaves their finger and goes to the ice (and not that the ice transfers cold to their finger, as I expected them to think). Several students even explained that their fingers feel cold because objects at a higher temperature release heat until they reach equilibrium with their surroundings. One explained that as the heat transferred, the finger's temperature went down and hence the finger got cold. I asked one of these students where they learned all this and they said last year in Chemistry. The one student that answered incorrectly assumed that the ice transferred cold energy to his finger.

ut I expanded my inquiry a little and discovered that the "by the book" answer students gave was a little too canned. I increased the level of difficulty by a factor and gave the same ten students the following scenario: I hold an iron bar with my hand. I put the iron bar to a fire. After a while, my hand feels hot. Why? All students correctly answered that the fire transferred heat to the bar and the bar transferred heat to their hands. Now, start over. I hold an iron bar with my hand. I put the iron bar to ice. My hand feels cold. Why? Only five students realized that it was the same situation as with the finger directly touching the ice. They said that the bar transfers heat from the hand to the ice. The other five gave essentially two kinds of responses: three said that the ice transferred cold/heat energy/its temperature to the bar and then to the hand (regressing to a pre-chemistry conceptual discrepancy that most people have), and two said that no energy is transferred at all. One of the students suspected his explanation was not right but that nevertheless he would find out why in a couple of weeks when we study this stuff in class.

It is almost as if the bar was an unexpected "interference" in their conceptual schema that they could not cope with and then regressed back to their pre-chemistry notions of heat transfer. 

Then I "upped the ante" and asked them a related question: how does an air conditioner or refrigerator work to cool the air in a room or a freezer compartment. One student gave a clinical explanation of how the air conditioner contains a fluid that extracts heat from the air in the room/compartment. Another mentioned that the AC/refrigerator contains a gas that cools the air. Four students said that the AC/refrigerator absorbs/filters the air, thereby taking away the heat from it. The others gave various erroneous versions of the "magic box" explanation: the AC/refrigerator magically "cools" the air; three said that the AC produces/makes cool air (in the sense of manufacturing); one said that that the AC converts the electrical energy into thermal energy (no doubt capitalizing on our main theme in Physics this year: Conservation of Energy and energy transformations).

Again, there was a notable confusion as to what cooling is: withdrawing heat or adding cold.

A side note: I also asked students if the same air that was inside the room was being cooled or whether the air was taken out and new air pumped in. I may have asked a leading question though since I reminded students before they answered that air conditioners have two components: a part inside the room and a part outside regardless of whether they are wall mounted or split units. Seven students said that the air conditioner extracts the warm air from the room and brought new air in (two reasoned that this was true because if you stand outside next to an AC you feel hot air blown from the back. They failed to realize that the heat was being ejected from the room not the air). One student said that the air conditioner just takes the warm air out but doesn't bring new air in (not realizing that if this were true the room would become evacuated of air). One student said that it is the same air that is in the room before and after but did not justify why. Only one could justify why it was illogical that air be brought in from outside since the air outside was even hotter than the air inside.

My general conclusion about these results is that students have a conceptual discrepancy about the nature of heat itself. They fail to realize that heat is energy in motion between two objects at different temperatures and that it always travels from the hotter object to the cooler one (unless external work is done). They seem to think that the energy is indivisible from the object that contains the energy and therefore the objects (in the case of the AC or refrigerator, the air) must move physically from one place to another (from inside the room/compartment to outside) instead of the energy moving. Because of their misunderstanding of the nature of heat, and that it can exist to a greater or lesser degree, they believe that cold also exists and flows. It is almost as if the existence of a purposeful God (heat) necessitated the existence of the Devil (cold).

What do you think? Any extra ideas or questions I might ask them? It was really interesting doing this active research on-the-job. I'm really beginning to see how finding out what students' prior knowledge is can be helpful in teaching a new unit.

Russell

 

 

FOURTH CONTACT WITH MENTOR

From:	kardenas@att.net Save Address - Block Sender
To:	"Russbecca Krummell" <russbecca@hotmail.com> Save Address
Subject:	Action Research/Prior Knowledge
Date:	Fri, 31 Mar 2000 15:31:49 +0000

Reply

Reply All

Forward

Delete

Previous

Next

Close

Good Morning Russell:

I really liked your method of probing for energy misconceptions.  The gradual increase in level of difficulty allows you to obtain concrete evidence for your assumptions about your students.  Now I would like to present an outline for you to create and document discrepant events.  Discrepant events allow students to work with a problem and use their prior knowledge to solve problem as successfully as possible with very minimal teacher instruction/guidance.

The basic difference in what you are doing and the discrepant event(DE) is that DE allows you to probe more to reveal the underlying nature of your students alternative conceptions.

Here is an outline for preparing "mini" lessons for a discrepant event (DE).  Following the outline, I will give you some guidelines. Please take a look at them also.
1.  Title of you event......
2.  Purpose of the lesson (Objective).....
3.  Questions you will ask to arouse curiosity......
4.  Procedure you will follow in presenting the evcent (teacher activity and student activity).......
5.  Closure of the lesson (include application and elaboration)
6.  Equipment and/or materials (be specific)

Here are some guidlines:
1.  State an opening questions arousing curiosity about the event (energy related in your case).
2.  Set the event.  As students are comleting the activity, try to begin  by asking open-ended questions, then move to higher level questions (open-ended), then intermix them to lead the students towards a well thought-out solution.
3.  Ask leading questions, but do not give the students the answers (similar to what you have done).
4.  if the students answers are not correct >> You should respond with probing questions such as "You have an interestin approach, please explain your reasoning behind it? Or why do think "it" occurred that way?
5.  Now relatet the DE to your curriculum (concept you are teaching).
6.  Have your students design questions about the DE that are based on what they have learned.  This will give you insight into the student's understanding of the event.  This goes a step beyond identifying their alternative conception(AC).  Now you understand why they thing the way they do.  This will enable you to change their AC.
7.  Have your students develop some hypothesis that they can test in order to explain the DE.
8.  Provide examples of how the underlying concetps and other related concepts of the DE are used in everyday life.

Now you may use and modify this information to "best" suit your needs.  I know that you are focusing on the concept of energy (tranfer, forms, etc. Here are some possible activities to develop for prio knowledge

1.  An electric circuit (light source, battery)
2.  Pose the question: Would it take more energy to change a gram of solid to liquid or a gram of the same liquid to a gas.  (You could easily demonstrate this one with ice).
3.  Is Alka Selzter in water an example of an endothermic or exothermic reaction.  Explain, why or why not based on temperature change. you could really do alot with this one.  

There are several concepts you could explore. I could give you more examples, if you tell me specifically the unit of chemistry you are covering or what topic you are on.  Thanks.  I will talk with you tonight.  I hope this has helped.  Discrepant events are good because you will use them during the explaration phase of the learning cycle.  They challenge your students prior knowledge.  They cause disequlibrium - a prerequisite for learning.  Also please tell me once again the grade level.  I hope that I have not bombarded you with too many "atoms".  Let's talk soon.  Is this what you need from me?  Good Luck.  Please tell Dr. Sunal I said Hello him.

FIFTH CONTACT WITH MENTOR

Dear Kimberly:Thanks for the guidance on how to do the Learning Cycle. I followed Dr. Sunal's Lesson Plan Format for Learning Cycles in a photocopied compilation that he gave those of us who are taking CSE 565 (he is teaching a combined class with both elementary and secondary students). The lesson plan is reproduced below: Key Question (to introduce Discrepant Event): A refrigerator is running in the middle of a classroom at room temperature. What would happen to the temperature in the room if the door of the refrigerator were left open?Goal: Students will be able to: correctly explain that heat is transferred away from substances to cool them and that it must be accounted for as with all forms of energy.  correctly explain that heat naturally transfers from hot to cold unless external work is done. Prerequisite skills and concepts: familiarity with the concepts of WORK and ENERGY working knowledge of the LAW of CONSERVATION OF ENERGYknowledge of how to write a correct hypothesisexposure to basic design of HEAT ENGINES (HEAT PUMPS)EXPLORATION PHASE:OBJECTIVES: Students will be able to: predict what will happen to the temperature in a room when the door of a refrigerator in the room is left open  form testable hypotheses about why the temperature changes/stays the same in a room in which a refrigerator is running with the door open work effectively in a dyad dissect a cooler into its main components by function MATERIALS: OVERHEAD: with Key QuestionOVERHEAD: Compare cooler with refrigeratorLarge sheets of white construction paperMarkers1. Pose key question to class; put up OVERHEAD2. Have students individually predict the result and then hypothesize why (in writing). 3. Divide students into groups of two. Have them share their individual conclusions and then come up with at least two testable hypotheses and write them on their poster paper in large readable type (posters should be legible from any chair in the classroom). 4. Have groups draw a cross section of a cooler with every component part it needs to do its job properly and the function of each part. Give students a minimum number of parts (say five) to force them to stretch their schemas. 5. Put up OVERHEAD: Ask groups to compare and contrast a COLEMAN cooler with a refrigerator. How are they alike and how are they different (again, have them list at least five similarities and differences to stretch their schemas). INVENTION PHASEOBJECTIVES: Students will be able to: recognize a refrigerator as a heat pump in reverse describe the operation of a simple manual heat pump working in reverse define the process of heat transfer from a heat sink to a heat reservoir as another manifestation of WORK share their results orally and in written form with a scientific communityMATERIALS: copies of unlabeled heat pump diagram 6. Have groups explain on their posters what would have to be done to keep the contents of a cooler cool if the cooler's lid were open. Ans. Ice would have to be added periodically.7. Define the action of keeping the cooler's contents cool as WORK. 8. Give students a drawing of a simple heat pump diagram with no labeled parts and have students label the parts and show the direction of heat flow in the refrigerator. ___________________ ________________ \ / \ / \______________________/ ______________________ / \ / \ __________________/ \________________9. Articulate for students that a cooler/refrigerator is a simple HEAT PUMP in reverse (removing heat from the heat sink and transferring it to the heat reservoir (the environment).10. Have groups revisit their hypotheses and decide if any changes should be made. If they will change their hypothesis, they should only cross their old hypotheses out with one line (so they are still legible) and write their new hypotheses below.11. Evaluation: Collect and hang up the posters around the room. Open up the class for discussion about the results and the hypotheses and especially about the evolution of thought and reasons that the hypotheses changed as new information was assimilated. EXPANSION PHASE:OBJECTIVES: Students will be able toapply their new concept to a situation that is a slight variation of the original situation (a refrigerator in a cold room)clarify the heat sink and heat reservoir concept in a heat pumpclarify what heat transfer really meansexplore language and meaning nuances that contribute and impair communicationMATERIALS: Class set of envelopes with cut outs of refrigerator (or cooler) partsOVERHEAD: Student explanation12. Have students, in their dyads, explain what would happen to room temperature if the refrigerator were placed in a cold room and the door was left open.13. Put up OVERHEAD: Have students, in their dyads, debunk the following student explanation: An air conditioner throws the warm air in a room outside. That is why the air conditioner feels warm outside and that’s why air conditioners have a part inside the room and a part outside (like a split unit). But where does a cooler throw the heat if it is perfectly insulated from the outside environment? NEXT KEY QUESTION for LEARNING CYCLE #2: If I am sweating, why do I feel cool when a fan blows on my skin? EXPLORATION ACTIVITY: Put some water on a large cork and set a watch crystal or a piece of tinfoil shaped into a small dish on it. Into this dish pour a little alcohol or ether (keep away from open flames) and make it evaporate rapidly by vigorous fanning. Enough heat will be carried away to turn the water into snow, or even to freeze the dish firmly to the cork.This will lead to an eventual EXPANSION PHASE in which students explain how a refrigerant works to cool the air in a refrigerator.Dr. Sunal accepted the above Learning Cycle #1 with a few suggestions. He suggested that the students be grouped in threes or fours instead of twos (in the Exploration Phase) to generate more discussion. He also pointed out that evaluation, the final component, was missing from each phase; he simply wrote that the evaluation in each phase could be "the degree of completion of tasks and degree of cooperative work in groups".For Learning Cycle #2, I will include the missing evaluation component and also the elements you said were missing, specifically1. Title of the lesson2. More of the teachers role as a wanderer and thought-provoker roving between groups and asking open-ended questions3. Have students design questions about the DE thatare based on what they have learned (we could play 20 Questions so students can get information from me and I will be getting info from them simultaneously about what they are thinking...A Nobel Prize Winner in Physics once said that it is by the quality of questions asked that one knows the thought processes). As an added incentive, I could give bonus points to the group that gets the "correct" hypothesis first. I'm teaching 12th grade physics by the way, not chemistry. Thanks for your help! My second learning cycle talks, as it says above, gets into the nitty gritty of how air conditioners and refrigerators really work (principle behind the coolant).Talk to you soon,Russell

[Back to Top]