An Energy Concept Inventory

1. An Energy Concept Inventory The FITW Physics Study Group Gregg Swackhamer Glenbrook North High School Modeling Instruction Project

2. Designing the assessment • FIRST IN THE WORLD Physics Team • ASU graduate students • Dwayne Desbien, Eric Brewe • ASU faculty: David Hestenes, Larry Dukerich • Literature review (1970’s to now) • Textbook review (1900 to now) • Seminal papers (Mayer, Joule, Maxwell, etc.)

3. Designing the assessment • All energy is stored in some physical system. • Energy can be transferred from one thing to another. This causes changes. • The amount of energy in the universe is constant. Energy cannot be made, nor can it be destroyed. • Energy tends to disperse to more and more objects. Entropy can be made, but it cannot be destroyed.

4. Results 5. You have a can of soda that you would like to keep cold and a sandwich to keep warm. You have woolen blankets and some aluminum foil. What combination of materials would work best? a. Aluminum foil wrapped around the soda and a woolen blanket wrapped around the sandwich. b. A woolen blanket wrapped around the soda and aluminum foil wrapped around the sandwich c. Aluminum foil wrapped around each. d. A woolen blanket wrapped around each. e. Wrapping with either material would work equally well. 52% 56% 11% 6% 26% 27% 4% 3% 7% 5%

5. Results • 30. Which of the following statements describe the difference between a strong chemical bond and a weak chemical bond between two atoms? • i. The strong chemical bond stores more energy than the weak chemical bond. • ii. More energy is needed to separate strongly bonded atoms than weakly bonded atoms. • iii. More energy is released to the environment when two atoms become strongly bonded than when two atoms become weakly bonded. • a. i only • b. ii only • c. iii only • d. ii and iii only • e. i, ii, and iii 33% 30% 4% 28% 5%

6. Results • 21. A steel ball rolls along a smooth, hard, level surface with a certain speed. It then smoothly rolls up and over the hill shown below. How does its speed after it rolls over the hill compare to its speed before it rolls over the hill? • a. Its speed is significantly less after it rolls over the hill than before it rolls over it. • b. Its speed is very nearly the same after it rolls over the hill as before it rolls over it. • c. Its speed is slightly greater after it rolls over the hill than before it rolls over it. • d. Its speed is much greater after it rolls over the hill than before it rolls over it. • e. The information is insufficient to answer the question. 5% 11% 17% 17% 22% 20% 54% 48% 3% 4%

7. Results 24. A small ice cube is placed in a refrigerator that maintains a temperature of 5˚C. At that moment the ice cube is observed to have a temperature of 0˚C. What will happen to the temperature of the ice? a. It will decrease until the ice is completely melted. b. It will remain 0˚C until the ice is completely melted. c. It gradually increases to as much as 5˚C as it melts. d. It increases to 5˚C, then the ice begins to melt. e. It will fluctuate between 0˚C and 5˚C as ice is melting. 23% 17% 22% 15% 30% 48% 12% 11% 13% 7%

8. Results 26. A living tree in its environment a. does not contain energy. b. contains energy that it has received from the sun. c. contains energy that it has made as well as energy that it has received from the sun. d. contains only energy that it has made. e. contains energy from the sun and the energy of its life force. 2% 9% 30% 28% 43% 57% 5% 2% 18% 4%

9. Results 27. A dead tree in its environment a. does not contain energy. b. contains energy that it has received from the sun. c. contains energy that it has made as well as energy that it has received from the sun. d. contains only energy that it has made. e. contains energy from the sun and the energy of its life force. 58% 35% 14% 24% 6% 17% 9% 11% 9% 13%

10. Results 29. When a candle burns the energy released a. comes mainly from the wax and air. b. comes mainly from the burning wick. c. is produced mainly by the fire. d. comes from the match that lighted the candle. e. comes mainly from the wax. 19% 11% 30% 26% 32% 52% 9% 7% 8% 4%

11. Results 35. A balloon is inflated with a mixture of natural gas and air. A burning match is touched to the balloon, and the mixture explodes. The energy released by the explosion a. was originally in the natural gas and air. b. came from the match. c. was not originally in the natural gas and air but was produced in the reaction between the natural gas and air. d. was originally in only the natural gas. e. was originally in only the air. 17% 20% 18% 22% 42% 37% 15% 13% 5% 7%

12. Findings • Students have an incoherent view of energy. • Potential energy is often ignored. • “Just a number” • “An invented quantity” • Potential energy is not actual energy. • It often is thought to have nowhere to exist, so it cannot really exist.

13. Findings • Students have an incoherent view of energy. • Energy can be “produced.” • Energy conservation only weakly constrains student thinking. It does not force inferences. • Energy is not useful to students in describing and explaining natural phenomena. • They often have to be prompted even to invoke it!

14. Findings • Textbooks present a fragmented and sometimes misleading view of energy. • Energy is said to be “invented,” and “abstract.” • Energy can be “converted” to different “forms.”

15. Findings • National science standards present a problematic view of energy. The opening sentence of the energy section in the AAAS/Project 2061 Standards: “Energy is a mysterious concept….”

16. Findings Energetik: Energy is the fundamental reality. Changes in nature are transformations of energy. “Advantage” of Energetik: No need for matter in general, nor especially for atoms!

17. Findings “In speaking of the Energy of the field, however, I wish to be understood literally. All energy is the same as mechanical energy, whether it exists in the form of motion or in that of elasticity, or in any other form. The energy in electromagnetic phenomena is mechanical energy. The only question is, Where does it reside?”

18. Findings Understanding of energy concept =UE Understanding of particle models for matter =UPM [UPM]= gPM,E[UE] gPM,Eis a very strong coupling constant in need of investigation.

19. Findings • After four years of energy instruction, students do not find energy to be very useful, even for prototypical school science phenomena.

20. Recommendations • Energy must be presented as a single concept. • Energy does not come in different “forms.” It is only stored in different things. • There is only one kind of energy: Energy

21. Recommendations • The energy concept must be associated with appropriate intuitions. The substance metaphor is the central cognitive resource for conserved, extensive quantities.

22. Recommendations • Physics first: Enormous opportunity to serve chemistry and biology… Revamped content…à la Karplus A coherent energy concept first Bound systems

23. Recommendations • Students need to use better representational tools for systems, energy, and energy transfers. • See Larry Dukerich tomorrow at 9:00 am, Session CL For more information: http://modeling.asu.edu pswackhamer@glenbrook.k12.il.us