# PowerPoint Presentation by A4A11h

VIEWS: 13 PAGES: 176

• pg 1
```									                                 Percentage of Sample

0
5
10
15
20
25
0- 1
0                                 30
101 0
- 12
126 5
- 15
0
151
- 17
5
176
- 20
201 0
- 22
5
226
- 25
251 0
- 27
5
276
- 30
301 0
- 32
5

326
- 35
0
351
- 37
Full Class, N = 424, median grade = 261

376 5
- 40
0
Interview Sample, N = 32, median grade = 305

400
+
VB
W    VA   P dV
VB
W    VA   P dV
VB
W    VA   P dV
100
Correct responses (%)

80
Intro Physics, Pretest

60                                            Intro Physics, Posttest

Thermal Physics, Pretest
40
Thermal Physics, Posttest
20

0
S(system)   S(surroundings)   S(total)
Correct Responses
Spring 2005, Fall 2005, Spring 2006 (N = 609)

60%

50%

40%

30%           50%                 49%

20%

10%                                                   14%
5%
0%
Entropy change of   Entropy change of Entropy of object +   All Correct
object not      air in the room not air in the room
determinable         determinable        increases
Pre-Instruction Responses Consistent
with Entropy "Conservation"
General-Context Question (N = 1184)   Concrete-Context Question (N = 609)

80%
70%
60%
50%
40%
66%      71%
30%
20%                                                  38%
29%                            26%
10%                                                                                 22%
0%
Total entropy [(system +        Argument #1: (a) and (b)     Argument #2: (a) increases
surroundings) / (object + air)] undeterminable, but (c) total     (or decreases) and (b)
remains the same            entropy remains the same decreases (or increases), but
(c) total entropy remains the
same
General-Context Question Pre-Instruction vs.
Post-Instruction
Before Instruction (N = 1184)      After Instruction (N = 255)

70%

60%

50%

40%
66%
30%                    56%

20%
29%                                         27%
10%                                                     20%                      26%

0%
Total entropy [(system +          Argument #1: (a) and (b)        Argument #2: (a) increases (or
surroundings) / (object + air)]   undeterminable, but (c) total   decreases) and (b) decreases (or
remains the same              entropy remains the same        increases), but (c) total entropy
remains the same
Concrete-Context Question, Pre-Instruction vs.
Post-Instruction
Before Instruction (N = 609)        After Instruction (N = 251)

80%

70%

60%

50%

40%

71%       68%
30%

20%
38%       35%

10%                                                                              22%       22%

0%
Total entropy [(system +         Argument #1: (a) and (b)         Argument #2: (a) increases (or
surroundings) / (object + air)]   undeterminable, but (c) total   decreases) and (b) decreases (or
remains the same              entropy remains the same        increases), but (c) total entropy
remains the same
100
Correct responses (%)

80
Intro Physics, Pretest

60                                            Intro Physics, Posttest

Thermal Physics, Pretest
40
Thermal Physics, Posttest

20

0
S(system)   S(surroundings)   S(total)
Q                    Q
S total                                          0
Tcold reservoir       Thot reservoir
Q                    Q
S total                                          0
Tcold reservoir       Thot reservoir
Pre-instruction (N = 1184)
Post-instruction, no tutorial (N = 255)
Post-instruction, with tutorial (N = 237)

80%
70%

60%
50%

40%
30%
20%

10%
0%

S(total) correct          All three questions correct
Pre-instruction   Post-instruction, with tutorial

90%
80%
70%
60%
50%
40%
30%
20%
10%
0%

S(total) correct         All three questions correct

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