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Title: Developing Improved Curricula and Instructional Methods based on Physics Education Research


1
Developing Improved Curricula and Instructional
Methods based on Physics Education Research
  • David E. Meltzer
  • Department of Physics and Astronomy
  • Iowa State University
  • Ames, Iowa
  • Supported by the U.S. National Science Foundation

2
Outline
  • Research-Based Curriculum Development
  • Overview
  • Investigation of Students Reasoning
  • Students reasoning in thermodynamics
  • Students reasoning in calorimetry
  • Diverse representational modes in student
    learning
  • Curriculum Development
  • Curricular materials for thermodynamics
  • Curricular materials for calorimetry

3
Outline
  • Research-Based Curriculum Development
  • Overview
  • Investigation of Students Reasoning
  • Students reasoning in thermodynamics
  • Students reasoning in calorimetry
  • Diverse representational modes in student
    learning
  • Curriculum Development
  • Curricular materials for thermodynamics
  • Curricular materials for calorimetry

4
Outline
  • Research-Based Curriculum Development
  • Overview
  • Investigation of Students Reasoning
  • Students reasoning in thermodynamics
  • Students reasoning in calorimetry
  • Diverse representational modes in student
    learning
  • Curriculum Development
  • Curricular materials for thermodynamics
  • Curricular materials for calorimetry

5
Outline
  • Research-Based Curriculum Development
  • Overview
  • Investigation of Students Reasoning
  • Students reasoning in thermodynamics
  • Students reasoning in calorimetry
  • Diverse representational modes in student
    learning
  • Curriculum Development
  • Curricular materials for thermodynamics
  • Curricular materials for calorimetry

6
Outline
  • Research-Based Curriculum Development
  • Overview
  • Investigation of Students Reasoning
  • Students reasoning in thermodynamics
  • Students reasoning in calorimetry
  • Diverse representational modes in student
    learning
  • Curriculum Development
  • Curricular materials for thermodynamics
  • Curricular materials for calorimetry

7
Outline
  • Research-Based Curriculum Development
  • Overview
  • Investigation of Students Reasoning
  • Students reasoning in thermodynamics
  • Students reasoning in calorimetry
  • Diverse representational modes in student
    learning
  • Curriculum Development
  • Curricular materials for thermodynamics
  • Curricular materials for calorimetry

8
Outline
  • Research-Based Curriculum Development
  • Overview
  • Investigation of Students Reasoning
  • Students reasoning in thermodynamics
  • Students reasoning in calorimetry
  • Diverse representational modes in student
    learning
  • Curriculum Development
  • Curricular materials for thermodynamics
  • Curricular materials for calorimetry

9
Outline
  • Research-Based Curriculum Development
  • Overview
  • Investigation of Students Reasoning
  • Students reasoning in thermodynamics
  • Students reasoning in calorimetry
  • Diverse representational modes in student
    learning
  • Curriculum Development
  • Curricular materials for thermodynamics
  • Curricular materials for calorimetry

10
Outline
  • Research-Based Curriculum Development
  • Overview
  • Investigation of Students Reasoning
  • Students reasoning in thermodynamics
  • Students reasoning in calorimetry
  • Diverse representational modes in student
    learning
  • Curriculum Development
  • Curricular materials for thermodynamics
  • Curricular materials for calorimetry

11
Outline
  • Research-Based Curriculum Development
  • Overview
  • Investigation of Students Reasoning
  • Students reasoning in thermodynamics
  • Students reasoning in calorimetry
  • Diverse representational modes in student
    learning
  • Curriculum Development
  • Curricular materials for thermodynamics
  • Curricular materials for calorimetry

12
Curriculum-Development Process
  • Carefully investigate students reasoning when
    learning with standard instruction
  • Identify principal learning difficulties
  • due to preconceptions, or that arise during
    instruction
  • Develop instructional strategies
  • Test, assess, and revise new instructional
    materials

13
Curriculum-Development Process
  • Carefully investigate students reasoning when
    learning with standard instruction
  • Identify principal learning difficulties
  • due to preconceptions, or that arise during
    instruction
  • Develop instructional strategies
  • Test, assess, and revise new instructional
    materials

14
Curriculum-Development Process
  • Carefully investigate students reasoning when
    learning with standard instruction
  • Identify principal learning difficulties
  • due to preconceptions, or that arise during
    instruction
  • Develop instructional strategies
  • Test, assess, and revise new instructional
    materials

15
Curriculum-Development Process
  • Carefully investigate students reasoning when
    learning with standard instruction
  • Identify principal learning difficulties
  • due to preconceptions, or that arise during
    instruction
  • Develop instructional strategies
  • Test, assess, and revise new instructional
    materials

16
Curriculum-Development Process
  • Carefully investigate students reasoning when
    learning with standard instruction
  • Identify principal learning difficulties
  • due to preconceptions, or that arise during
    instruction
  • Develop instructional strategies
  • Test, assess, and revise new instructional
    materials

17
Curriculum-Development Process
  • Carefully investigate students reasoning when
    learning with standard instruction
  • Identify principal learning difficulties
  • due to preconceptions, or that arise during
    instruction
  • Develop instructional strategies
  • Test, assess, and revise new instructional
    materials

18
Outline
  • Research-Based Curriculum Development
  • Overview
  • Investigation of Students Reasoning
  • Students reasoning in thermodynamics
  • Students reasoning in calorimetry
  • Diverse representational modes in student
    learning
  • Curriculum Development
  • Curricular materials for thermodynamics
  • Curricular materials for calorimetry

19
Outline
  • Research-Based Curriculum Development
  • Overview
  • Investigation of Students Reasoning
  • Students reasoning in thermodynamics
  • Students reasoning in calorimetry
  • Diverse representational modes in student
    learning
  • Curriculum Development
  • Curricular materials for thermodynamics
  • Curricular materials for calorimetry

20
Previous Work
  • There have been more than 200 investigations of
    pre-college students learning of thermodynamics
    concepts, all showing serious conceptual
    difficulties.
  • Recently published study of university students
    showed substantial difficulty with work concept
    and with the first law of thermodynamics. M.E.
    Loverude, C.H. Kautz, and P.R.L. Heron, Am. J.
    Phys. 70, 137 (2002).
  • Until now there has been no detailed study of
    thermodynamics knowledge of students in
    introductory (first-year) calculus-based general
    physics course.

21
Previous Work
  • There have been more than 200 investigations of
    pre-college students learning of thermodynamics
    concepts, all showing serious conceptual
    difficulties.
  • Recently published study of university students
    showed substantial difficulty with work concept
    and with the first law of thermodynamics. M.E.
    Loverude, C.H. Kautz, and P.R.L. Heron, Am. J.
    Phys. 70, 137 (2002).
  • Until now there has been no detailed study of
    thermodynamics knowledge of students in
    introductory (first-year) calculus-based general
    physics course.

22
Previous Work
  • There have been more than 200 investigations of
    pre-college students learning of thermodynamics
    concepts, all showing serious conceptual
    difficulties.
  • Recently published study of university students
    showed substantial difficulty with work concept
    and with the first law of thermodynamics. M.E.
    Loverude, C.H. Kautz, and P.R.L. Heron, Am. J.
    Phys. 70, 137 (2002).
  • Until now there has been no detailed study of
    thermodynamics knowledge of students in
    introductory (first-year) calculus-based general
    physics course.

23
Previous Work
  • There have been more than 200 investigations of
    pre-college students learning of thermodynamics
    concepts, all showing serious conceptual
    difficulties.
  • Recently published study of university students
    showed substantial difficulty with work concept
    and with the first law of thermodynamics. M.E.
    Loverude, C.H. Kautz, and P.R.L. Heron, Am. J.
    Phys. 70, 137 (2002).
  • Until now there has been only limited study of
    thermodynamics knowledge of students in
    introductory (first-year) calculus-based general
    physics course.

24
Research Basis for Curriculum Development (NSF
CCLI Project with T. Greenbowe)
  • Investigation of second-semester calculus-based
    physics course (mostly engineering students).
  • Written diagnostic questions administered last
    week of class in 1999, 2000, and 2001 (Ntotal
    653).
  • Detailed interviews (avg. duration ? one hour)
    carried out with 32 volunteers during 2002 (total
    class enrollment 424).
  • interviews carried out after all thermodynamics
    instruction completed

two course instructors, ? 20 recitation
instructors
25
Research Basis for Curriculum Development (NSF
CCLI Project with T. Greenbowe)
  • Investigation of second-semester calculus-based
    physics course (mostly engineering students).
  • Written diagnostic questions administered last
    week of class in 1999, 2000, and 2001 (Ntotal
    653).
  • Detailed interviews (avg. duration ? one hour)
    carried out with 32 volunteers during 2002 (total
    class enrollment 424).
  • interviews carried out after all thermodynamics
    instruction completed

two course instructors, ? 20 recitation
instructors
26
Research Basis for Curriculum Development (NSF
CCLI Project with T. Greenbowe)
  • Investigation of second-semester calculus-based
    physics course (mostly engineering students).
  • Written diagnostic questions administered last
    week of class in 1999, 2000, and 2001 (Ntotal
    653).
  • Detailed interviews (avg. duration ? one hour)
    carried out with 32 volunteers during 2002 (total
    class enrollment 424).
  • interviews carried out after all thermodynamics
    instruction completed

two course instructors, ? 20 recitation
instructors
27
Research Basis for Curriculum Development (NSF
CCLI Project with T. Greenbowe)
  • Investigation of second-semester calculus-based
    physics course (mostly engineering students).
  • Written diagnostic questions administered last
    week of class in 1999, 2000, and 2001 (Ntotal
    653).
  • Detailed interviews (avg. duration ? one hour)
    carried out with 32 volunteers during 2002 (total
    class enrollment 424).
  • interviews carried out after all thermodynamics
    instruction completed

two course instructors, ? 20 recitation
instructors
28
Research Basis for Curriculum Development (NSF
CCLI Project with T. Greenbowe)
  • Investigation of second-semester calculus-based
    physics course (mostly engineering students).
  • Written diagnostic questions administered last
    week of class in 1999, 2000, and 2001 (Ntotal
    653).
  • Detailed interviews (avg. duration ? one hour)
    carried out with 32 volunteers during 2002 (total
    class enrollment 424).
  • interviews carried out after all thermodynamics
    instruction completed

two course instructors, ? 20 recitation
instructors
29
Research Basis for Curriculum Development (NSF
CCLI Project with T. Greenbowe)
  • Investigation of second-semester calculus-based
    physics course (mostly engineering students).
  • Written diagnostic questions administered last
    week of class in 1999, 2000, and 2001 (Ntotal
    653).
  • Detailed interviews (avg. duration ? one hour)
    carried out with 32 volunteers during 2002 (total
    class enrollment 424).
  • interviews carried out after all thermodynamics
    instruction completed
  • final grades of interview sample far above class
    average

two course instructors, ? 20 recitation
instructors
30
Research Basis for Curriculum Development (NSF
CCLI Project with T. Greenbowe)
  • Investigation of second-semester calculus-based
    physics course (mostly engineering students).
  • Written diagnostic questions administered last
    week of class in 1999, 2000, and 2001 (Ntotal
    653).
  • Detailed interviews (avg. duration ? one hour)
    carried out with 32 volunteers during 2002 (total
    class enrollment 424).
  • interviews carried out after all thermodynamics
    instruction completed
  • final grades of interview sample far above class
    average

two course instructors, ? 20 recitation
instructors
31
Grade Distributions Interview Sample vs. Full
Class
32
Grade Distributions Interview Sample vs. Full
Class
Interview Sample 34 above 91st percentile 50
above 81st percentile
33
Predominant Themes of Students Reasoning
  1. Understanding of concept of state function in the
    context of energy.
  2. Belief that work is a state function.
  3. Belief that heat is a state function.
  4. Failure to recognize work as a mechanism of
    energy transfer.
  5. Confusion regarding isothermal processes and the
    thermal reservoir.
  6. Belief that net work done and net heat
    transferred during a cyclic process are zero.
  7. Inability to apply the first law of
    thermodynamics.

34
Predominant Themes of Students Reasoning
  1. Understanding of concept of state function in the
    context of energy.
  2. Belief that work is a state function.
  3. Belief that heat is a state function.
  4. Belief that net work done and net heat
    transferred during a cyclic process are zero.
  5. Inability to apply the first law of
    thermodynamics.

35
Predominant Themes of Students Reasoning
  1. Understanding of concept of state function in the
    context of energy.
  2. Belief that work is a state function.
  3. Belief that heat is a state function.
  4. Belief that net work done and net heat
    transferred during a cyclic process are zero.
  5. Inability to apply the first law of
    thermodynamics.

36
Predominant Themes of Students Reasoning
  1. Understanding of concept of state function in the
    context of energy.
  2. Belief that work is a state function.
  3. Belief that heat is a state function.
  4. Belief that net work done and net heat
    transferred during a cyclic process are zero.
  5. Inability to apply the first law of
    thermodynamics.

37
Predominant Themes of Students Reasoning
  1. Understanding of concept of state function in the
    context of energy.
  2. Belief that work is a state function.
  3. Belief that heat is a state function.
  4. Belief that net work done and net heat
    transferred during a cyclic process are zero.
  5. Inability to apply the first law of
    thermodynamics.

38
Predominant Themes of Students Reasoning
  1. Understanding of concept of state function in the
    context of energy.
  2. Belief that work is a state function.
  3. Belief that heat is a state function.
  4. Belief that net work done and net heat
    transferred during a cyclic process are zero.
  5. Inability to apply the first law of
    thermodynamics.

39
Predominant Themes of Students Reasoning
  1. Understanding of concept of state function in the
    context of energy.
  2. Belief that work is a state function.
  3. Belief that heat is a state function.
  4. Belief that net work done and net heat
    transferred during a cyclic process are zero.
  5. Inability to apply the first law of
    thermodynamics.

40
Understanding of Concept of State Function in the
Context of Energy
  • Diagnostic question two different processes
    connecting identical initial and final states.
  • Do students realize that only initial and final
    states determine change in a state function?

41
Understanding of Concept of State Function in the
Context of Energy
  • Diagnostic question two different processes
    connecting identical initial and final states.
  • Do students realize that only initial and final
    states determine change in a state function?

42
Understanding of Concept of State Function in the
Context of Energy
  • Diagnostic question two different processes
    connecting identical initial and final states.
  • Do students realize that only initial and final
    states determine change in a state function?

43
This P-V diagram represents a system consisting
of a fixed amount of ideal gas that undergoes two
different processes in going from state A to
state B
In these questions, W represents the work done
by the system during a process Q represents the
heat absorbed by the system during a process.
  1. Is W for Process 1 greater than, less
than, or equal to that for Process 2?
Explain.   2. Is Q for Process 1 greater than,
less than, or equal to that for Process 2?   3.
Which would produce the largest change in the
total energy of all the atoms in the system
Process 1, Process 2, or both processes produce
the same change?
44
This P-V diagram represents a system consisting
of a fixed amount of ideal gas that undergoes two
different processes in going from state A to
state B
In these questions, W represents the work done
by the system during a process Q represents the
heat absorbed by the system during a process.
  1. Is W for Process 1 greater than, less
than, or equal to that for Process 2?
Explain.   2. Is Q for Process 1 greater than,
less than, or equal to that for Process 2?   3.
Which would produce the largest change in the
total energy of all the atoms in the system
Process 1, Process 2, or both processes produce
the same change?
45
This P-V diagram represents a system consisting
of a fixed amount of ideal gas that undergoes two
different processes in going from state A to
state B
In these questions, W represents the work done
by the system during a process Q represents the
heat absorbed by the system during a process.
  1. Is W for Process 1 greater than, less
than, or equal to that for Process 2?
Explain.   2. Is Q for Process 1 greater than,
less than, or equal to that for Process 2?   3.
Which would produce the largest change in the
total energy of all the atoms in the system
Process 1, Process 2, or both processes produce
the same change?
46
This P-V diagram represents a system consisting
of a fixed amount of ideal gas that undergoes two
different processes in going from state A to
state B
In these questions, W represents the work done
by the system during a process Q represents the
heat absorbed by the system during a process.
  1. Is W for Process 1 greater than, less
than, or equal to that for Process 2?
Explain.   2. Is Q for Process 1 greater than,
less than, or equal to that for Process 2?   3.
Which would produce the largest change in the
total energy of all the atoms in the system
Process 1, Process 2, or both processes produce
the same change?
47
This P-V diagram represents a system consisting
of a fixed amount of ideal gas that undergoes two
different processes in going from state A to
state B
?U1 ?U2
In these questions, W represents the work done
by the system during a process Q represents the
heat absorbed by the system during a process.
  1. Is W for Process 1 greater than, less
than, or equal to that for Process 2?
Explain.   2. Is Q for Process 1 greater than,
less than, or equal to that for Process 2?   3.
Which would produce the largest change in the
total energy of all the atoms in the system
Process 1, Process 2, or both processes produce
the same change?
48
This P-V diagram represents a system consisting
of a fixed amount of ideal gas that undergoes two
different processes in going from state A to
state B
?U1 ?U2
In these questions, W represents the work done
by the system during a process Q represents the
heat absorbed by the system during a process.
  1. Is W for Process 1 greater than, less
than, or equal to that for Process 2?
Explain.   2. Is Q for Process 1 greater than,
less than, or equal to that for Process 2?   3.
Which would produce the largest change in the
total energy of all the atoms in the system
Process 1, Process 2, or both processes produce
the same change?
49
Students seem to have adequate grasp of
state-function concept
  • Consistently high percentage (70-90) of correct
    responses on relevant questions.
  • Large proportion of correct explanations.
  • Interview subjects displayed good understanding
    of state-function idea.
  • Students major conceptual difficulties stemmed
    from overgeneralization of state-function
    concept.

50
Students seem to have adequate grasp of
state-function concept
  • Consistently high percentage (70-90) of correct
    responses on relevant questions, with good
    explanations.
  • Interview subjects displayed good understanding
    of state-function idea.
  • Students major conceptual difficulties stemmed
    from overgeneralization of state-function
    concept.

51
Students seem to have adequate grasp of
state-function concept
  • Consistently high percentage (70-90) of correct
    responses on relevant questions, with good
    explanations.
  • Interview subjects displayed good understanding
    of state-function idea.
  • Students major conceptual difficulties stemmed
    from overgeneralization of state-function
    concept.

52
Students seem to have adequate grasp of
state-function concept
  • Consistently high percentage (70-90) of correct
    responses on relevant questions with good
    explanations.
  • Interview subjects displayed good understanding
    of state-function idea.
  • Students major conceptual difficulties stemmed
    from overgeneralization of state-function
    concept.

53
Students seem to have adequate grasp of
state-function concept
  • Consistently high percentage (70-90) of correct
    responses on relevant questions, with good
    explanations.
  • Interview subjects displayed good understanding
    of state-function idea.
  • Students major conceptual difficulties stemmed
    from overgeneralization of state-function
    concept. Details to follow . . .

54
Predominant Themes of Students Reasoning
  1. Understanding of concept of state function in the
    context of energy.
  2. Belief that work is a state function.
  3. Belief that heat is a state function.
  4. Belief that net work done and net heat
    transferred during a cyclic process are zero.
  5. Inability to apply the first law of
    thermodynamics.

55
Predominant Themes of Students Reasoning
  1. Understanding of concept of state function in the
    context of energy.
  2. Belief that work is a state function.
  3. Belief that heat is a state function.
  4. Belief that net work done and net heat
    transferred during a cyclic process are zero.
  5. Inability to apply the first law of
    thermodynamics.

56
This P-V diagram represents a system consisting
of a fixed amount of ideal gas that undergoes two
different processes in going from state A to
state B
In these questions, W represents the work done
by the system during a process Q represents the
heat absorbed by the system during a process.
  1. Is W for Process 1 greater than, less
than, or equal to that for Process 2?
Explain.   2. Is Q for Process 1 greater than,
less than, or equal to that for Process 2?   3.
Which would produce the largest change in the
total energy of all the atoms in the system
Process 1, Process 2, or both processes produce
the same change?
57
This P-V diagram represents a system consisting
of a fixed amount of ideal gas that undergoes two
different processes in going from state A to
state B
In these questions, W represents the work done
by the system during a process Q represents the
heat absorbed by the system during a process.
  1. Is W for Process 1 greater than, less
than, or equal to that for Process 2?
Explain.   2. Is Q for Process 1 greater than,
less than, or equal to that for Process 2?   3.
Which would produce the largest change in the
total energy of all the atoms in the system
Process 1, Process 2, or both processes produce
the same change?
58
This P-V diagram represents a system consisting
of a fixed amount of ideal gas that undergoes two
different processes in going from state A to
state B
In these questions, W represents the work done
by the system during a process Q represents the
heat absorbed by the system during a process.
  1. Is W for Process 1 greater than, less
than, or equal to that for Process 2?
Explain.   2. Is Q for Process 1 greater than,
less than, or equal to that for Process 2?   3.
Which would produce the largest change in the
total energy of all the atoms in the system
Process 1, Process 2, or both processes produce
the same change?
59
This P-V diagram represents a system consisting
of a fixed amount of ideal gas that undergoes two
different processes in going from state A to
state B
W1 gt W2
In these questions, W represents the work done
by the system during a process Q represents the
heat absorbed by the system during a process.
  1. Is W for Process 1 greater than, less
than, or equal to that for Process 2?
Explain.   2. Is Q for Process 1 greater than,
less than, or equal to that for Process 2?   3.
Which would produce the largest change in the
total energy of all the atoms in the system
Process 1, Process 2, or both processes produce
the same change?
60
This P-V diagram represents a system consisting
of a fixed amount of ideal gas that undergoes two
different processes in going from state A to
state B
W1 gt W2
In these questions, W represents the work done
by the system during a process Q represents the
heat absorbed by the system during a process.
  1. Is W for Process 1 greater than, less
than, or equal to that for Process 2?
Explain.   2. Is Q for Process 1 greater than,
less than, or equal to that for Process 2?   3.
Which would produce the largest change in the
total energy of all the atoms in the system
Process 1, Process 2, or both processes produce
the same change?
61
Responses to Diagnostic Question 1 (Work
question)
1999 (N186) 2000 (N188) 2001 (N279) 2002 Interview Sample (N32)
W1 gt W2
W1 W2
W1 lt W2
62
Responses to Diagnostic Question 1 (Work
question)
1999 (N186) 2000 (N188) 2001 (N279) 2002 Interview Sample (N32)
W1 gt W2
W1 W2
W1 lt W2
63
Responses to Diagnostic Question 1 (Work
question)
1999 (N186) 2000 (N188) 2001 (N279) 2002 Interview Sample (N32)
W1 W2 25 26 35


64
Responses to Diagnostic Question 1 (Work
question)
1999 (N186) 2000 (N188) 2001 (N279) 2002 Interview Sample (N32)
W1 W2 25 26 35
Because work is independent of path 14 23

explanations not required in 1999
65
Responses to Diagnostic Question 1 (Work
question)
1999 (N186) 2000 (N188) 2001 (N279) 2002 Interview Sample (N32)
W1 W2 25 26 35 22
Because work is independent of path 14 23 22

explanations not required in 1999
66
Responses to Diagnostic Question 1 (Work
question)
1999 (N186) 2000 (N188) 2001 (N279) 2002 Interview Sample (N32)
W1 W2 25 26 35 22
Because work is independent of path 14 23 22
Other reason, or none 12 13 0
explanations not required in 1999
67
Explanations Given by Interview Subjects to
Justify W1 W2
  • Work is a state function.
  • No matter what route you take to get to state B
    from A, its still the same amount of work.
  • For work done take state A minus state B the
    process to get there doesnt matter.
  • Many students come to associate work with
    properties (and descriptive phrases) only used by
    instructors in connection with state functions.

68
Explanations Given by Interview Subjects to
Justify W1 W2
  • Work is a state function.
  • No matter what route you take to get to state B
    from A, its still the same amount of work.
  • For work done take state A minus state B the
    process to get there doesnt matter.
  • Many students come to associate work with
    properties (and descriptive phrases) only used by
    instructors in connection with state functions.

69
Explanations Given by Interview Subjects to
Justify W1 W2
  • Work is a state function.
  • No matter what route you take to get to state B
    from A, its still the same amount of work.
  • For work done take state A minus state B the
    process to get there doesnt matter.
  • Many students come to associate work with
    properties (and descriptive phrases) only used by
    instructors in connection with state functions.

70
Explanations Given by Interview Subjects to
Justify W1 W2
  • Work is a state function.
  • No matter what route you take to get to state B
    from A, its still the same amount of work.
  • For work done take state A minus state B the
    process to get there doesnt matter.
  • Many students come to associate work with
    properties (and descriptive phrases) only used by
    instructors in connection with state functions.

71
Explanations Given by Interview Subjects to
Justify W1 W2
  • Work is a state function.
  • No matter what route you take to get to state B
    from A, its still the same amount of work.
  • For work done take state A minus state B the
    process to get there doesnt matter.
  • Many students come to associate work with
    properties (and descriptive phrases) only used by
    instructors in connection with state functions.

72
Explanations Given by Interview Subjects to
Justify W1 W2
  • Work is a state function.
  • No matter what route you take to get to state B
    from A, its still the same amount of work.
  • For work done take state A minus state B the
    process to get there doesnt matter.
  • Many students come to associate work with
    properties (and descriptive phrases) only used by
    instructors in connection with state functions.

Confusion with mechanical work done by
conservative forces?
73
Predominant Themes of Students Reasoning
  1. Understanding of concept of state function in the
    context of energy.
  2. Belief that work is a state function.
  3. Belief that heat is a state function.
  4. Belief that net work done and net heat
    transferred during a cyclic process are zero.
  5. Inability to apply the first law of
    thermodynamics.

74
Predominant Themes of Students Reasoning
  1. Understanding of concept of state function in the
    context of energy.
  2. Belief that work is a state function.
  3. Belief that heat is a state function.
  4. Belief that net work done and net heat
    transferred during a cyclic process are zero.
  5. Inability to apply the first law of
    thermodynamics.

75
This P-V diagram represents a system consisting
of a fixed amount of ideal gas that undergoes two
different processes in going from state A to
state B
In these questions, W represents the work done
by the system during a process Q represents the
heat absorbed by the system during a process.
  1. Is W for Process 1 greater than, less
than, or equal to that for Process 2?
Explain.   2. Is Q for Process 1 greater than,
less than, or equal to that for Process 2?   3.
Which would produce the largest change in the
total energy of all the atoms in the system
Process 1, Process 2, or both processes produce
the same change?
76
This P-V diagram represents a system consisting
of a fixed amount of ideal gas that undergoes two
different processes in going from state A to
state B
In these questions, W represents the work done
by the system during a process Q represents the
heat absorbed by the system during a process.
  1. Is W for Process 1 greater than, less
than, or equal to that for Process 2?
Explain.   2. Is Q for Process 1 greater than,
less than, or equal to that for Process 2?   3.
Which would produce the largest change in the
total energy of all the atoms in the system
Process 1, Process 2, or both processes produce
the same change?
77
This P-V diagram represents a system consisting
of a fixed amount of ideal gas that undergoes two
different processes in going from state A to
state B
Change in internal energy is the same for
Process 1 and Process 2.
In these questions, W represents the work done
by the system during a process Q represents the
heat absorbed by the system during a process.
  1. Is W for Process 1 greater than, less
than, or equal to that for Process 2?
Explain.   2. Is Q for Process 1 greater than,
less than, or equal to that for Process 2?   3.
Which would produce the largest change in the
total energy of all the atoms in the system
Process 1, Process 2, or both processes produce
the same change?
78
This P-V diagram represents a system consisting
of a fixed amount of ideal gas that undergoes two
different processes in going from state A to
state B
The system does more work in Process 1, so it
must absorb more heat to reach same final value
of internal energy Q1 gt Q2
Change in internal energy is the same for
Process 1 and Process 2.
In these questions, W represents the work done
by the system during a process Q represents the
heat absorbed by the system during a process.
  1. Is W for Process 1 greater than, less
than, or equal to that for Process 2?
Explain.   2. Is Q for Process 1 greater than,
less than, or equal to that for Process 2?   3.
Which would produce the largest change in the
total energy of all the atoms in the system
Process 1, Process 2, or both processes produce
the same change?
79
This P-V diagram represents a system consisting
of a fixed amount of ideal gas that undergoes two
different processes in going from state A to
state B
The system does more work in Process 1, so it
must absorb more heat to reach same final value
of internal energy Q1 gt Q2
Change in internal energy is the same for
Process 1 and Process 2.
In these questions, W represents the work done
by the system during a process Q represents the
heat absorbed by the system during a process.
  1. Is W for Process 1 greater than, less
than, or equal to that for Process 2?
Explain.   2. Is Q for Process 1 greater than,
less than, or equal to that for Process 2?   3.
Which would produce the largest change in the
total energy of all the atoms in the system
Process 1, Process 2, or both processes produce
the same change?
80
This P-V diagram represents a system consisting
of a fixed amount of ideal gas that undergoes two
different processes in going from state A to
state B
In these questions, W represents the work done
by the system during a process Q represents the
heat absorbed by the system during a process.
  1. Is W for Process 1 greater than, less
than, or equal to that for Process 2?
Explain.   2. Is Q for Process 1 greater than,
less than, or equal to that for Process 2?   3.
Which would produce the largest change in the
total energy of all the atoms in the system
Process 1, Process 2, or both processes produce
the same change?
81
This P-V diagram represents a system consisting
of a fixed amount of ideal gas that undergoes two
different processes in going from state A to
state B
Algebraic Method ?U1 ?U2 Q1 W1 Q2
W2
In these questions, W represents the work done
by the system during a process Q represents the
heat absorbed by the system during a process.
  1. Is W for Process 1 greater than, less
than, or equal to that for Process 2?
Explain.   2. Is Q for Process 1 greater than,
less than, or equal to that for Process 2?   3.
Which would produce the largest change in the
total energy of all the atoms in the system
Process 1, Process 2, or both processes produce
the same change?
82
This P-V diagram represents a system consisting
of a fixed amount of ideal gas that undergoes two
different processes in going from state A to
state B
Algebraic Method ?U1 ?U2 Q1 W1 Q2
W2 W1 W2 Q1 Q2
In these questions, W represents the work done
by the system during a process Q represents the
heat absorbed by the system during a process.
  1. Is W for Process 1 greater than, less
than, or equal to that for Process 2?
Explain.   2. Is Q for Process 1 greater than,
less than, or equal to that for Process 2?   3.
Which would produce the largest change in the
total energy of all the atoms in the system
Process 1, Process 2, or both processes produce
the same change?
83
This P-V diagram represents a system consisting
of a fixed amount of ideal gas that undergoes two
different processes in going from state A to
state B
Algebraic Method ?U1 ?U2 Q1 W1 Q2
W2 W1 W2 Q1 Q2
W1 gt W2 ? Q1 gt Q2
In these questions, W represents the work done
by the system during a process Q represents the
heat absorbed by the system during a process.
  1. Is W for Process 1 greater than, less
than, or equal to that for Process 2?
Explain.   2. Is Q for Process 1 greater than,
less than, or equal to that for Process 2?   3.
Which would produce the largest change in the
total energy of all the atoms in the system
Process 1, Process 2, or both processes produce
the same change?
84
This P-V diagram represents a system consisting
of a fixed amount of ideal gas that undergoes two
different processes in going from state A to
state B
Algebraic Method ?U1 ?U2 Q1 W1 Q2
W2 W1 W2 Q1 Q2
W1 gt W2 ? Q1 gt Q2
In these questions, W represents the work done
by the system during a process Q represents the
heat absorbed by the system during a process.
  1. Is W for Process 1 greater than, less
than, or equal to that for Process 2?
Explain.   2. Is Q for Process 1 greater than,
less than, or equal to that for Process 2?   3.
Which would produce the largest change in the
total energy of all the atoms in the system
Process 1, Process 2, or both processes produce
the same change?
85
Responses to Diagnostic Question 2 (Heat
question)
1999 (N186) 2000 (N188) 2001 (N279) 2002 Interview Sample (N32)
Q1 gt Q2
Q1 Q2
Q1 lt Q2
86
Responses to Diagnostic Question 2 (Heat
question)
1999 (N186) 2000 (N188) 2001 (N279) 2002 Interview Sample (N32)
Q1 gt Q2
Q1 Q2
Q1 lt Q2
87
Responses to Diagnostic Question 2 (Heat
question)
1999 (N186) 2000 (N188) 2001 (N279) 2002 Interview Sample (N32)
Q1 Q2


88
Responses to Diagnostic Question 2 (Heat
question)
1999 (N186) 2000 (N188) 2001 (N279) 2002 Interview Sample (N32)
Q1 Q2 31 43 41 47


89
Responses to Diagnostic Question 2 (Heat
question)
1999 (N186) 2000 (N188) 2001 (N279) 2002 Interview Sample (N32)
Q1 Q2 31 43 41 47
Because heat is independent of path 21 23 20

90
Responses to Diagnostic Question 2 (Heat
question)
1999 (N186) 2000 (N188) 2001 (N279) 2002 Interview Sample (N32)
Q1 Q2 31 43 41 47
Because heat is independent of path 21 23 20 44

91
Responses to Diagnostic Question 2 (Heat
question)
1999 (N186) 2000 (N188) 2001 (N279) 2002 Interview Sample (N32)
Q1 Q2 31 43 41 47
Because heat is independent of path 21 23 20 44
Other explanation, or none 10 18 20 3
92
Explanations Given by Interview Subjects to
Justify Q1 Q2
  • I believe that heat transfer is like energy in
    the fact that it is a state function and doesnt
    matter the path since they end at the same
    point.
  • Transfer of heat doesnt matter on the path you
    take.
  • They both end up at the same PV value so . . .
    They both have the same Q or heat transfer.
  • Almost 200 students offered arguments similar to
    these either in their written responses or during
    the interviews.

93
Explanations Given by Interview Subjects to
Justify Q1 Q2
  • I believe that heat transfer is like energy in
    the fact that it is a state function and doesnt
    matter the path since they end at the same
    point.
  • Transfer of heat doesnt matter on the path you
    take.
  • They both end up at the same PV value so . . .
    They both have the same Q or heat transfer.
  • Almost 200 students offered arguments similar to
    these either in their written responses or during
    the interviews.

94
Explanations Given by Interview Subjects to
Justify Q1 Q2
  • I believe that heat transfer is like energy in
    the fact that it is a state function and doesnt
    matter the path since they end at the same
    point.
  • Transfer of heat doesnt matter on the path you
    take.
  • They both end up at the same PV value so . . .
    They both have the same Q or heat transfer.
  • Almost 200 students offered arguments similar to
    these either in their written responses or during
    the interviews.

95
Explanations Given by Interview Subjects to
Justify Q1 Q2
  • I believe that heat transfer is like energy in
    the fact that it is a state function and doesnt
    matter the path since they end at the same
    point.
  • Transfer of heat doesnt matter on the path you
    take.
  • They both end up at the same PV value so . . .
    They both have the same Q or heat transfer.
  • Almost 200 students offered arguments similar to
    these either in their written responses or during
    the interviews.

96
Explanations Given by Interview Subjects to
Justify Q1 Q2
  • I believe that heat transfer is like energy in
    the fact that it is a state function and doesnt
    matter the path since they end at the same
    point.
  • Transfer of heat doesnt matter on the path you
    take.
  • They both end up at the same PV value so . . .
    They both have the same Q or heat transfer.
  • Almost 150 students offered arguments similar to
    these either in their written responses or during
    the interviews.

97
Explanations Given by Interview Subjects to
Justify Q1 Q2
  • I believe that heat transfer is like energy in
    the fact that it is a state function and doesnt
    matter the path since they end at the same
    point.
  • Transfer of heat doesnt matter on the path you
    take.
  • They both end up at the same PV value so . . .
    They both have the same Q or heat transfer.
  • Almost 150 students offered arguments similar to
    these either in their written responses or during
    the interviews. Confusion with Q mc?T ?

98
Predominant Themes of Students Reasoning
  1. Understanding of concept of state function in the
    context of energy.
  2. Belief that work is a state function.
  3. Belief that heat is a state function.
  4. Belief that net work done and net heat
    transferred during a cyclic process are zero.
  5. Inability to apply the first law of
    thermodynamics.

99
Predominant Themes of Students Reasoning
  1. Understanding of concept of state function in the
    context of energy.
  2. Belief that work is a state function.
  3. Belief that heat is a state function.
  4. Belief that net work done and net heat
    transferred during a cyclic process are zero.
  5. Inability to apply the first law of
    thermodynamics.

100
Interview Questions
  • A fixed quantity of ideal gas is contained
    within a metal cylinder that is sealed with a
    movable, frictionless, insulating piston.
  • The cylinder is surrounded by a large container
    of water with high walls as shown. We are going
    to describe two separate processes, Process 1
    and Process 2.

101
Interview Questions
  • A fixed quantity of ideal gas is contained
    within a metal cylinder that is sealed with a
    movable, frictionless, insulating piston.
  • The cylinder is surrounded by a large container
    of water with high walls as shown. We are going
    to describe two separate processes, Process 1
    and Process 2.

102
Interview Questions
  • A fixed quantity of ideal gas is contained
    within a metal cylinder that is sealed with a
    movable, frictionless, insulating piston.
  • The cylinder is surrounded by a large container
    of water with high walls as shown. We are going
    to describe two separate processes, Process 1
    and Process 2.

103
Interview Questions
  • A fixed quantity of ideal gas is contained
    within a metal cylinder that is sealed with a
    movable, frictionless, insulating piston.
  • The cylinder is surrounded by a large container
    of water with high walls as shown. We are going
    to describe two separate processes, Process 1
    and Process 2.

104
At initial time A, the gas, cylinder, and water
have all been sitting in a room for a long period
of time, and all of them are at room temperature
Time A Entire system at room temperature.
105
This diagram was not shown to students
106
This diagram was not shown to students
initial state
107
At initial time A, the gas, cylinder, and water
have all been sitting in a room for a long period
of time, and all of them are at room temperature
Time A Entire system at room temperature.
108
Step 1. We now begin Process 1 The water
container is gradually heated, and the piston
very slowly moves upward. At time B the heating
of the water stops, and the piston stops moving
when it is in the position shown in the diagram
below
109
Step 1. We now begin Process 1 The water
container is gradually heated, and the piston
very slowly moves upward. At time B the heating
of the water stops, and the piston stops moving
when it is in the position shown in the diagram
below
110
Step 1. We now begin Process 1 The water
container is gradually heated, and the piston
very slowly moves upward. At time B the heating
of the water stops, and the piston stops moving
when it is in the position shown in the diagram
below
111
This diagram was not shown to students
112
This diagram was not shown to students
113
This diagram was not shown to students
114
Step 1. We now begin Process 1 The water
container is gradually heated, and the piston
very slowly moves upward. At time B the heating
of the water stops, and the piston stops moving
when it is in the position shown in the diagram
below
Question 1 During the process that occurs from
time A to time B, which of the following is true
(a) positive work is done on the gas by the
environment, (b) positive work is done by the gas
on the environment, (c) no net work is done on or
by the gas.
115
Step 2. Now, empty containers are placed on top
of the piston as shown. Small lead weights are
gradually placed in the containers, one by one,
and the piston is observed to move down slowly.
While this happens, the temperature of the water
is nearly unchanged, and the gas temperature
remains practically constant. (That is, it
remains at the temperature it reached at time B,
after the water had been heated up.)
116
Step 2. Now, empty containers are placed on top
of the piston as shown. Small lead weights are
gradually placed in the containers, one by one,
and the piston is observed to move down slowly.
While this happens, the temperature of the water
is nearly unchanged, and the gas temperature
remains practically constant. (That is, it
remains at the temperature it reached at time B,
after the water had been heated up.)
117
Step 2. Now, empty containers are placed on top
of the piston as shown. Small lead weights are
gradually placed in the containers, one by one,
and the piston is observed to move down slowly.
While this happens, the temperature of the water
is nearly unchanged, and the gas temperature
remains practically constant. (That is, it
remains at the temperature it reached at time B,
after the water had been heated up.)
weights being added Piston moves down slowly.
Temperature remains same as at time B.
118
Step 2. Now, empty containers are placed on top
of the piston as shown. Small lead weights are
gradually placed in the containers, one by one,
and the piston is observed to move down slowly.
While this happens, the temperature of the water
is nearly unchanged, and the gas temperature
remains practically constant. (That is, it
remains at the temperature it reached at time B,
after the water had been heated up.)
weights being added Piston moves down slowly.
Temperature remains same as at time B.
119
Step 3. At time C we stop adding lead weights to
the container and the piston stops moving. (The
weights that we have already added up until now
are still in the containers.) The piston is now
found to be at exactly the same position it was
at time A .
120
Step 3. At time C we stop adding lead weights to
the container and the piston stops moving. (The
weights that we have already added up until now
are still in the containers.) The piston is now
found to be at exactly the same position it was
at time A .
Time C  Weights in containers. Piston in same
position as at time A. Temperature same as at
time B.
121
Step 3. At time C we stop adding lead weights to
the container and the piston stops moving. (The
weights that we have already added up until now
are still in the containers.) The piston is now
found to be at exactly the same position it was
at time A .
Time C  Weights in containers. Piston in same
position as at time A. Temperature same as at
time B.
122
This diagram was not shown to students
123
This diagram was not shown to students
124
This diagram was not shown to students
?TBC 0
125
Step 3. At time C we stop adding lead weights to
the container and the piston stops moving. (The
weights that we have already added up until now
are still in the containers.) The piston is now
found to be at exactly the same position it was
at time A .
Time C  Weights in containers. Piston in same
position as at time A. Temperature same as at
time B.
126
Step 4. Now, the piston is locked into place so
it cannot move the weights are removed from the
piston. The system is left to sit in the room for
many hours, and eventually the entire system
cools back down to the same room temperature it
had at time A. When this finally happens, it is
time D.
127
Step 4. Now, the piston is locked into place so
it cannot move the weights are removed from the
piston. The system is left to sit in the room for
many hours, and eventually the entire system
cools back down to the same room temperature it
had at time A. When this finally happens, it is
time D.
128
Step 4. Now, the piston is locked into place so
it cannot move the weights are removed from the
piston. The system is left to sit in the room for
many hours, and eventually the entire system
cools back down to the same room temperature it
had at time A. When this finally happens, it is
time D.
Time D Piston in same position as at time
A. Temperature same as at time A.
129
This diagram was not shown to students
130
This diagram was not shown to students
131
This diagram was not shown to students
132
Time D Piston in same position as at time
A. Temperature same as at time A.
  • Question 6 Consider the entire process from
    time A to time D.
  • (i) Is the net work done by the gas on the
    environment during that process (a) greater than
    zero, (b) equal to zero, or (c) less than zero?
  • (ii) Is the total heat transfer to the gas
    during that process (a) greater than zero, (b)
    equal to zero, or (c) less than zero?

133
Time D Piston in same position as at time
A. Temperature same as at time A.
  • Question 6 Consider the entire process from
    time A to time D.
  • (i) Is the net work done by the gas on the
    environment during that process (a) greater than
    zero, (b) equal to zero, or (c) less than zero?
  • (ii) Is the total heat transfer to the gas
    during that process (a) greater than zero, (b)
    equal to zero, or (c) less than zero?

134
This diagram was not shown to students
135
This diagram was not shown to students
WBC gt WAB
136
This diagram was not shown to students
WBC gt WAB WBC lt 0
137
This diagram was not shown to students
WBC gt WAB WBC lt 0 ? Wnet lt 0
138
Time D Piston in same position as at time
A. Temperature same as at time A.
  • Question 6 Consider the entire process from
    time A to time D.
  • (i) Is the net work done by the gas on the
    environment during that process (a) greater than
    zero, (b) equal to zero, or (c) less than zero?
  • (ii) Is the total heat transfer to the gas
    during that process (a) greater than zero, (b)
    equal to zero, or (c) less than zero?

139
Time D Piston in same position as at time
A. Temperature same as at time A.
  • Question 6 Consider the entire process from
    time A to time D.
  • (i) Is the net work done by the gas on the
    environment during that process (a) greater than
    zero, (b) equal to zero, or (c) less than zero?
  • (ii) Is the total heat transfer to the gas
    during that process (a) greater than zero, (b)
    equal to zero, or (c) less than zero?

140
Results on Interview Question 6 (i)N 32
  • ( a ) Wnet gt 0 16
  • ( b ) Wnet 0 63
  • No response 3
  • Even after being asked to draw a P-V diagram for
    Process 1, nearly two thirds of the interview
    sample believed that net work done was equal to
    zero.

141
Results on Interview Question 6 (i)N 32
  • ( a ) Wnet gt 0 16
  • ( b ) Wnet 0 63
  • (c) Wnet lt 0 19 correct
  • No response 3
  • Even after being asked to draw a P-V diagram for
    Process 1, nearly two thirds of the interview
    sample believed that net work done was equal to
    zero.

142
Results on Interview Question 6 (i)N 32
  • (a) Wnet gt 0 16
  • ( b ) Wnet 0 63
  • (c) Wnet lt 0 19 correct
  • No response 3
  • Even after being asked to draw a P-V diagram for
    Process 1, nearly two thirds of the interview
    sample believed that net work done was equal to
    zero.

143
Results on Interview Question 6 (i)N 32
  • (a) Wnet gt 0 16
  • (b) Wnet 0 63
  • (c) Wnet lt 0 19 correct
  • No response 3
  • Even after being asked to draw a P-V diagram for
    Process 1, nearly two thirds of the interview
    sample believed that net work done was equal to
    zero.

144
Results on Interview Question 6 (i)N 32
  • (a) Wnet gt 0 16
  • (b) Wnet 0 63
  • (c) Wnet lt 0 19 correct
  • No response 3
  • Even after being asked to draw a P-V diagram for
    Process 1, nearly two thirds of the interview
    sample believed that net work done was equal to
    zero.

145
Results on Interview Question 6 (i)N 32
  • (a) Wnet gt 0 16
  • (b) Wnet 0 63
  • (c) Wnet lt 0 19 correct
  • No response 3
  • Even after being asked to draw a P-V diagram for
    Process 1, nearly two thirds of the interview
    sample believed that net work done was equal to
    zero.

146
Explanations offered for Wnet 0
  • Student 1 The physics definition of work is
    like force times distance. And basically if you
    use the same force and you just travel around in
    a circle and come back to your original spot,
    technically you did z
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