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![Page 1: Students Reasoning Regarding Electric Field Concepts Pre- and Post-Instruction David E. Meltzer Department of Physics and Astronomy Iowa State University.](https://reader036.fdocuments.in/reader036/viewer/2022062413/5a4d1b717f8b9ab0599b5535/html5/thumbnails/1.jpg)
Students’ Reasoning Regarding Electric Field Concepts
Pre- and Post-Instruction
David E. MeltzerDepartment of Physics and Astronomy
Iowa State University
Supported by NSF Grant REC-#0206683
![Page 2: Students Reasoning Regarding Electric Field Concepts Pre- and Post-Instruction David E. Meltzer Department of Physics and Astronomy Iowa State University.](https://reader036.fdocuments.in/reader036/viewer/2022062413/5a4d1b717f8b9ab0599b5535/html5/thumbnails/2.jpg)
Investigating Students’ Reasoning Through Detailed Analysis of Response Patterns
• Pattern of multiple-choice responses may offer evidence about students’ mental models.– R. J. Dufresne, W. J. Leonard, and W. J. Gerace, 2002.– L. Bao, K. Hogg, and D. Zollman, “Model Analysis,” 2002.
• Time-dependence of response pattern may give insight into evolution of students’ thinking.– R. Thornton, “Conceptual Dynamics,” 1997– D. Dykstra, “Essentialist Kinematics,” 2001– L. Bao and E. F. Redish, “Concentration Analysis,” 2001
![Page 3: Students Reasoning Regarding Electric Field Concepts Pre- and Post-Instruction David E. Meltzer Department of Physics and Astronomy Iowa State University.](https://reader036.fdocuments.in/reader036/viewer/2022062413/5a4d1b717f8b9ab0599b5535/html5/thumbnails/3.jpg)
Investigating Students’ Reasoning Through Detailed Analysis of Response Patterns
• Pattern of multiple-choice responses may offer evidence about students’ mental models.– R. J. Dufresne, W. J. Leonard, and W. J. Gerace, 2002.– L. Bao, K. Hogg, and D. Zollman, “Model Analysis,” 2002.
• Time-dependence of response pattern may give insight into evolution of students’ thinking.– R. Thornton, “Conceptual Dynamics,” 1997– D. Dykstra, “Essentialist Kinematics,” 2001– L. Bao and E. F. Redish, “Concentration Analysis,” 2001
![Page 4: Students Reasoning Regarding Electric Field Concepts Pre- and Post-Instruction David E. Meltzer Department of Physics and Astronomy Iowa State University.](https://reader036.fdocuments.in/reader036/viewer/2022062413/5a4d1b717f8b9ab0599b5535/html5/thumbnails/4.jpg)
Investigating Students’ Reasoning Through Detailed Analysis of Response Patterns
• Pattern of multiple-choice responses may offer evidence about students’ mental models.– R. J. Dufresne, W. J. Leonard, and W. J. Gerace, 2002.– L. Bao, K. Hogg, and D. Zollman, “Model Analysis,” 2002.
• Time-dependence of response pattern may give insight into evolution of students’ thinking.– R. Thornton, “Conceptual Dynamics,” 1997– D. Dykstra, “Essentialist Kinematics,” 2001– L. Bao and E. F. Redish, “Concentration Analysis,” 2001
![Page 5: Students Reasoning Regarding Electric Field Concepts Pre- and Post-Instruction David E. Meltzer Department of Physics and Astronomy Iowa State University.](https://reader036.fdocuments.in/reader036/viewer/2022062413/5a4d1b717f8b9ab0599b5535/html5/thumbnails/5.jpg)
Students’ Understanding of Representations in Electricity and
Magnetism• Analysis of responses to multiple-choice
diagnostic test “Conceptual Survey in Electricity” (Maloney, O’Kuma, Hieggelke, and Van Heuvelen, 2001)
• Administered 1998-2001 in algebra-based physics course at Iowa State [interactive-engagement instruction] (N = 299; matched sample)
• Additional data from students’ written explanations of their reasoning (2002, unmatched sample: pre-instruction, N = 72; post-instruction, N = 66)
![Page 6: Students Reasoning Regarding Electric Field Concepts Pre- and Post-Instruction David E. Meltzer Department of Physics and Astronomy Iowa State University.](https://reader036.fdocuments.in/reader036/viewer/2022062413/5a4d1b717f8b9ab0599b5535/html5/thumbnails/6.jpg)
Students’ Understanding of Representations in Electricity and
Magnetism• Analysis of responses to multiple-choice
diagnostic test “Conceptual Survey in Electricity” (Maloney, O’Kuma, Hieggelke, and Van Heuvelen, 2001)
• Administered 1998-2001 in algebra-based physics course at Iowa State [interactive-engagement instruction] (N = 299; matched sample)
• Additional data from students’ written explanations of their reasoning (2002, unmatched sample: pre-instruction, N = 72; post-instruction, N = 66)
![Page 7: Students Reasoning Regarding Electric Field Concepts Pre- and Post-Instruction David E. Meltzer Department of Physics and Astronomy Iowa State University.](https://reader036.fdocuments.in/reader036/viewer/2022062413/5a4d1b717f8b9ab0599b5535/html5/thumbnails/7.jpg)
Characterization of Students’ Background and Understanding
• Only about one third of students have had any previous exposure to electricity and/or magnetism concepts.
• Pre-Instruction: Responses to questions range from clear and acceptable explanations to uncategorizable outright guesses.
• Post-Instruction: Most explanations fall into fairly well-defined categories.
![Page 8: Students Reasoning Regarding Electric Field Concepts Pre- and Post-Instruction David E. Meltzer Department of Physics and Astronomy Iowa State University.](https://reader036.fdocuments.in/reader036/viewer/2022062413/5a4d1b717f8b9ab0599b5535/html5/thumbnails/8.jpg)
Characterization of Students’ Background and Understanding
• Only about one third of students have had any previous exposure to electricity and/or magnetism concepts.
• Pre-Instruction: Responses to questions range from clear and acceptable explanations to uncategorizable outright guesses.
• Post-Instruction: Most explanations fall into fairly well-defined categories.
![Page 9: Students Reasoning Regarding Electric Field Concepts Pre- and Post-Instruction David E. Meltzer Department of Physics and Astronomy Iowa State University.](https://reader036.fdocuments.in/reader036/viewer/2022062413/5a4d1b717f8b9ab0599b5535/html5/thumbnails/9.jpg)
Characterization of Students’ Background and Understanding
• Only about one third of students have had any previous exposure to electricity and/or magnetism concepts.
• Pre-Instruction: Responses to questions range from clear and acceptable explanations to uncategorizable outright guesses.
• Post-Instruction: Most explanations fall into fairly well-defined categories.
![Page 10: Students Reasoning Regarding Electric Field Concepts Pre- and Post-Instruction David E. Meltzer Department of Physics and Astronomy Iowa State University.](https://reader036.fdocuments.in/reader036/viewer/2022062413/5a4d1b717f8b9ab0599b5535/html5/thumbnails/10.jpg)
D. Maloney, T. O’Kuma, C. Hieggelke, and A. Van Heuvelen, PERS of Am. J. Phys. 69, S12 (2001).
#26-28
![Page 11: Students Reasoning Regarding Electric Field Concepts Pre- and Post-Instruction David E. Meltzer Department of Physics and Astronomy Iowa State University.](https://reader036.fdocuments.in/reader036/viewer/2022062413/5a4d1b717f8b9ab0599b5535/html5/thumbnails/11.jpg)
#26
![Page 12: Students Reasoning Regarding Electric Field Concepts Pre- and Post-Instruction David E. Meltzer Department of Physics and Astronomy Iowa State University.](https://reader036.fdocuments.in/reader036/viewer/2022062413/5a4d1b717f8b9ab0599b5535/html5/thumbnails/12.jpg)
#26
[correct]
W = qV; equal in I, II, and III
![Page 13: Students Reasoning Regarding Electric Field Concepts Pre- and Post-Instruction David E. Meltzer Department of Physics and Astronomy Iowa State University.](https://reader036.fdocuments.in/reader036/viewer/2022062413/5a4d1b717f8b9ab0599b5535/html5/thumbnails/13.jpg)
1998
E
C
B
A or D1999
A or D
B
C
E
2000A or D
BC
E
2001A or D
B
C
E
Pre-Instruction Responses to Question #26
![Page 14: Students Reasoning Regarding Electric Field Concepts Pre- and Post-Instruction David E. Meltzer Department of Physics and Astronomy Iowa State University.](https://reader036.fdocuments.in/reader036/viewer/2022062413/5a4d1b717f8b9ab0599b5535/html5/thumbnails/14.jpg)
0%
20%
40%
60%
80%
100%
Pretest Posttest
Responses to #26
E
D
C
B
AB B
C C
E E
1998-2001N = 299
![Page 15: Students Reasoning Regarding Electric Field Concepts Pre- and Post-Instruction David E. Meltzer Department of Physics and Astronomy Iowa State University.](https://reader036.fdocuments.in/reader036/viewer/2022062413/5a4d1b717f8b9ab0599b5535/html5/thumbnails/15.jpg)
#26
![Page 16: Students Reasoning Regarding Electric Field Concepts Pre- and Post-Instruction David E. Meltzer Department of Physics and Astronomy Iowa State University.](https://reader036.fdocuments.in/reader036/viewer/2022062413/5a4d1b717f8b9ab0599b5535/html5/thumbnails/16.jpg)
Explanations for #26 (Pre-Instruction: 60-90% categorizable)
• Response “B”– “Because the fields increase in strength as the object is
required to move through it”– “Because the equipotential lines are closest together”
• Response “C”– “Because they are far apart and work = force distance”
• Response “E” [correct]– “The electric potential difference is the same in all three
cases”
![Page 17: Students Reasoning Regarding Electric Field Concepts Pre- and Post-Instruction David E. Meltzer Department of Physics and Astronomy Iowa State University.](https://reader036.fdocuments.in/reader036/viewer/2022062413/5a4d1b717f8b9ab0599b5535/html5/thumbnails/17.jpg)
#26
![Page 18: Students Reasoning Regarding Electric Field Concepts Pre- and Post-Instruction David E. Meltzer Department of Physics and Astronomy Iowa State University.](https://reader036.fdocuments.in/reader036/viewer/2022062413/5a4d1b717f8b9ab0599b5535/html5/thumbnails/18.jpg)
Explanations for #26 (Pre-Instruction: 60-90% categorizable)
• Response “B”– “Because the fields increase in strength as the object is
required to move through it”– “Because the equipotential lines are closest together”
• Response “C”– “Because they are far apart and work = force distance”
• Response “E” [correct]– “The electric potential difference is the same in all three
cases”
![Page 19: Students Reasoning Regarding Electric Field Concepts Pre- and Post-Instruction David E. Meltzer Department of Physics and Astronomy Iowa State University.](https://reader036.fdocuments.in/reader036/viewer/2022062413/5a4d1b717f8b9ab0599b5535/html5/thumbnails/19.jpg)
Explanations for #26 (Pre-Instruction: 60-90% categorizable)
• Response “B”– “Because the fields increase in strength as the object is
required to move through it”– “Because the equipotential lines are closest together”
• Response “C”– “Because they are far apart and work = force distance”
• Response “E” [correct]– “The electric potential difference is the same in all three
cases”
![Page 20: Students Reasoning Regarding Electric Field Concepts Pre- and Post-Instruction David E. Meltzer Department of Physics and Astronomy Iowa State University.](https://reader036.fdocuments.in/reader036/viewer/2022062413/5a4d1b717f8b9ab0599b5535/html5/thumbnails/20.jpg)
0%
20%
40%
60%
80%
100%
Pretest Posttest
Responses to #26
E
D
C
B
AB B
C C
E E
1998-2001N = 299
![Page 21: Students Reasoning Regarding Electric Field Concepts Pre- and Post-Instruction David E. Meltzer Department of Physics and Astronomy Iowa State University.](https://reader036.fdocuments.in/reader036/viewer/2022062413/5a4d1b717f8b9ab0599b5535/html5/thumbnails/21.jpg)
0%
20%
40%
60%
80%
100%
Pretest Posttest
Responses to #26
E
D
C
B
AB B
C C
E E
1998-2001N = 299
![Page 22: Students Reasoning Regarding Electric Field Concepts Pre- and Post-Instruction David E. Meltzer Department of Physics and Astronomy Iowa State University.](https://reader036.fdocuments.in/reader036/viewer/2022062413/5a4d1b717f8b9ab0599b5535/html5/thumbnails/22.jpg)
Explanations for #26 (Post-Instruction: 70-100% categorizable)
• Proportion giving response “B” almost unchanged– “Because equipotential lines in II are closer together, the
magnitude of the electric force is greater and would need the most work to move the charges”
• Proportion giving response “C” decreases– “When the equipotential lines are farther apart it takes more
work to move the charge”
• Proportion giving correct response “E” increases– “Because the charge is moved across the same amount of
potential in each case”
![Page 23: Students Reasoning Regarding Electric Field Concepts Pre- and Post-Instruction David E. Meltzer Department of Physics and Astronomy Iowa State University.](https://reader036.fdocuments.in/reader036/viewer/2022062413/5a4d1b717f8b9ab0599b5535/html5/thumbnails/23.jpg)
Explanations for #26 (Post-Instruction: 70-100% categorizable)
• Proportion giving response “B” almost unchanged– “Because equipotential lines in II are closer together, the
magnitude of the electric force is greater and would need the most work to move the charges”
• Proportion giving response “C” decreases– “When the equipotential lines are farther apart it takes more
work to move the charge”
• Proportion giving correct response “E” increases– “Because the charge is moved across the same amount of
potential in each case”
![Page 24: Students Reasoning Regarding Electric Field Concepts Pre- and Post-Instruction David E. Meltzer Department of Physics and Astronomy Iowa State University.](https://reader036.fdocuments.in/reader036/viewer/2022062413/5a4d1b717f8b9ab0599b5535/html5/thumbnails/24.jpg)
Explanations for #26 (Post-Instruction: 70-100% categorizable)
• Proportion giving response “B” almost unchanged– “Because equipotential lines in II are closer together, the
magnitude of the electric force is greater and would need the most work to move the charges”
• Proportion giving response “C” decreases– “When the equipotential lines are farther apart it takes more
work to move the charge”
• Proportion giving correct response “E” increases– “Because the charge is moved across the same amount of
potential in each case”
![Page 25: Students Reasoning Regarding Electric Field Concepts Pre- and Post-Instruction David E. Meltzer Department of Physics and Astronomy Iowa State University.](https://reader036.fdocuments.in/reader036/viewer/2022062413/5a4d1b717f8b9ab0599b5535/html5/thumbnails/25.jpg)
#27
![Page 26: Students Reasoning Regarding Electric Field Concepts Pre- and Post-Instruction David E. Meltzer Department of Physics and Astronomy Iowa State University.](https://reader036.fdocuments.in/reader036/viewer/2022062413/5a4d1b717f8b9ab0599b5535/html5/thumbnails/26.jpg)
#27
closer spacing of equipotential lines larger magnitude field
[correct]
![Page 27: Students Reasoning Regarding Electric Field Concepts Pre- and Post-Instruction David E. Meltzer Department of Physics and Astronomy Iowa State University.](https://reader036.fdocuments.in/reader036/viewer/2022062413/5a4d1b717f8b9ab0599b5535/html5/thumbnails/27.jpg)
#30
*
(b) or (d) consistent with correct answer on #27
![Page 28: Students Reasoning Regarding Electric Field Concepts Pre- and Post-Instruction David E. Meltzer Department of Physics and Astronomy Iowa State University.](https://reader036.fdocuments.in/reader036/viewer/2022062413/5a4d1b717f8b9ab0599b5535/html5/thumbnails/28.jpg)
A, B
E
C
inconsistent
consistent
D
#27 Pre-test
“D”: closer spacing of equipotential lines stronger field“consistent”: consistent with answer on #30 (but some guesses)
Pre-Instruction
N = 299
![Page 29: Students Reasoning Regarding Electric Field Concepts Pre- and Post-Instruction David E. Meltzer Department of Physics and Astronomy Iowa State University.](https://reader036.fdocuments.in/reader036/viewer/2022062413/5a4d1b717f8b9ab0599b5535/html5/thumbnails/29.jpg)
Correct Answer, Incorrect Reasoning
• Nearly half of pre-instruction responses are correct, despite the fact that most students say they have not studied this topic
• Explanations offered include:
– “chose them in the order of closest lines”– “magnitude decreases with increasing distance”– “greatest because 50 [V] is so close”– “more force where fields are closest”– “because charges are closer together”– “guessed”
![Page 30: Students Reasoning Regarding Electric Field Concepts Pre- and Post-Instruction David E. Meltzer Department of Physics and Astronomy Iowa State University.](https://reader036.fdocuments.in/reader036/viewer/2022062413/5a4d1b717f8b9ab0599b5535/html5/thumbnails/30.jpg)
Correct Answer, Incorrect Reasoning
• Nearly half of pre-instruction responses are correct, despite the fact that most students say they have not studied this topic
• Explanations offered include:
– “chose them in the order of closest lines”– “magnitude decreases with increasing distance”– “greatest because 50 [V] is so close”– “more force where fields are closest”– “because charges are closer together”– “guessed”
![Page 31: Students Reasoning Regarding Electric Field Concepts Pre- and Post-Instruction David E. Meltzer Department of Physics and Astronomy Iowa State University.](https://reader036.fdocuments.in/reader036/viewer/2022062413/5a4d1b717f8b9ab0599b5535/html5/thumbnails/31.jpg)
Correct Answer, Incorrect Reasoning
• Nearly half of pre-instruction responses are correct, despite the fact that most students say they have not studied this topic
• Explanations offered include:
– “chose them in the order of closest lines”– “magnitude decreases with increasing distance”– “greatest because 50 [V] is so close”– “more force where fields are closest”– “because charges are closer together”– “guessed”
students’ initial “intuitions” may influence their learning
![Page 32: Students Reasoning Regarding Electric Field Concepts Pre- and Post-Instruction David E. Meltzer Department of Physics and Astronomy Iowa State University.](https://reader036.fdocuments.in/reader036/viewer/2022062413/5a4d1b717f8b9ab0599b5535/html5/thumbnails/32.jpg)
A, B
E
C
inconsistent
consistent
D
#27 Pre-test
“D”: closer spacing of equipotential lines stronger field“consistent”: consistent with answer on #30 (but some guesses)
Pre-Instruction
N = 299
![Page 33: Students Reasoning Regarding Electric Field Concepts Pre- and Post-Instruction David E. Meltzer Department of Physics and Astronomy Iowa State University.](https://reader036.fdocuments.in/reader036/viewer/2022062413/5a4d1b717f8b9ab0599b5535/html5/thumbnails/33.jpg)
D
C
E
A, B
consistent
inconsistent
#27 Post-test
Post-Instruction
Sharp increase in correct responses Correct responses more consistent with other answers
(and most explanations actually are consistent)
N = 299
![Page 34: Students Reasoning Regarding Electric Field Concepts Pre- and Post-Instruction David E. Meltzer Department of Physics and Astronomy Iowa State University.](https://reader036.fdocuments.in/reader036/viewer/2022062413/5a4d1b717f8b9ab0599b5535/html5/thumbnails/34.jpg)
#27
“C”: wider spacing of equipotential lines stronger field
![Page 35: Students Reasoning Regarding Electric Field Concepts Pre- and Post-Instruction David E. Meltzer Department of Physics and Astronomy Iowa State University.](https://reader036.fdocuments.in/reader036/viewer/2022062413/5a4d1b717f8b9ab0599b5535/html5/thumbnails/35.jpg)
#30
(a) or (c) consistent with “C” response on #27
![Page 36: Students Reasoning Regarding Electric Field Concepts Pre- and Post-Instruction David E. Meltzer Department of Physics and Astronomy Iowa State University.](https://reader036.fdocuments.in/reader036/viewer/2022062413/5a4d1b717f8b9ab0599b5535/html5/thumbnails/36.jpg)
D
C
EA,B
"consistent"
inconsistent
#27 Pre-testN = 299
“C”: wider spacing of equipotential lines stronger field“consistent”: apparently consistent with answer on #30
(but many inconsistent explanations)
Pre-Instruction
![Page 37: Students Reasoning Regarding Electric Field Concepts Pre- and Post-Instruction David E. Meltzer Department of Physics and Astronomy Iowa State University.](https://reader036.fdocuments.in/reader036/viewer/2022062413/5a4d1b717f8b9ab0599b5535/html5/thumbnails/37.jpg)
Students’ Explanations for Response “C” (Pre-Instruction)
• “III is the farthest apart, then I and then 2.”
• “The space between the fields is the greatest in III and the least in 2.”
• “The equipotential lines are farther apart so a greater magnitude is needed to maintain an electrical field.”
• “I guessed.”
![Page 38: Students Reasoning Regarding Electric Field Concepts Pre- and Post-Instruction David E. Meltzer Department of Physics and Astronomy Iowa State University.](https://reader036.fdocuments.in/reader036/viewer/2022062413/5a4d1b717f8b9ab0599b5535/html5/thumbnails/38.jpg)
Students’ Explanations for Response “C” (Pre-Instruction)
• “III is the farthest apart, then I and then 2.”
• “The equipotential lines are farther apart so a greater magnitude is needed to maintain an electrical field.”
• “I guessed.”
![Page 39: Students Reasoning Regarding Electric Field Concepts Pre- and Post-Instruction David E. Meltzer Department of Physics and Astronomy Iowa State University.](https://reader036.fdocuments.in/reader036/viewer/2022062413/5a4d1b717f8b9ab0599b5535/html5/thumbnails/39.jpg)
Students’ Explanations for Response “C” (Pre-Instruction)
• “III is the farthest apart, then I and then 2.”
• “The equipotential lines are farther apart so a greater magnitude is needed to maintain an electrical field.”
• “I guessed.”
![Page 40: Students Reasoning Regarding Electric Field Concepts Pre- and Post-Instruction David E. Meltzer Department of Physics and Astronomy Iowa State University.](https://reader036.fdocuments.in/reader036/viewer/2022062413/5a4d1b717f8b9ab0599b5535/html5/thumbnails/40.jpg)
D
C
EA,B
"consistent"
inconsistent
#27 Pre-testN = 299
“C”: wider spacing of equipotential lines stronger field“consistent”: apparently consistent with answer on #30
(but many inconsistent explanations)
Pre-Instruction
![Page 41: Students Reasoning Regarding Electric Field Concepts Pre- and Post-Instruction David E. Meltzer Department of Physics and Astronomy Iowa State University.](https://reader036.fdocuments.in/reader036/viewer/2022062413/5a4d1b717f8b9ab0599b5535/html5/thumbnails/41.jpg)
D
C
E
A, B
#27 Post-test
Proportion of responses in this category drastically reduced
Post-Instruction
N = 299
![Page 42: Students Reasoning Regarding Electric Field Concepts Pre- and Post-Instruction David E. Meltzer Department of Physics and Astronomy Iowa State University.](https://reader036.fdocuments.in/reader036/viewer/2022062413/5a4d1b717f8b9ab0599b5535/html5/thumbnails/42.jpg)
#27
“E”: magnitude of field scales with value of potential at given point
![Page 43: Students Reasoning Regarding Electric Field Concepts Pre- and Post-Instruction David E. Meltzer Department of Physics and Astronomy Iowa State University.](https://reader036.fdocuments.in/reader036/viewer/2022062413/5a4d1b717f8b9ab0599b5535/html5/thumbnails/43.jpg)
#30
(a) or (c) consistent with “E” response on #27
![Page 44: Students Reasoning Regarding Electric Field Concepts Pre- and Post-Instruction David E. Meltzer Department of Physics and Astronomy Iowa State University.](https://reader036.fdocuments.in/reader036/viewer/2022062413/5a4d1b717f8b9ab0599b5535/html5/thumbnails/44.jpg)
E
"consistent"
inconsistent
C
D
A,B
#27 Pre-test
“E”: magnitude of field scales with value of potential at point“consistent”: consistent with answer on #30 (but many guesses)
Pre-Instruction
N = 299
![Page 45: Students Reasoning Regarding Electric Field Concepts Pre- and Post-Instruction David E. Meltzer Department of Physics and Astronomy Iowa State University.](https://reader036.fdocuments.in/reader036/viewer/2022062413/5a4d1b717f8b9ab0599b5535/html5/thumbnails/45.jpg)
inconsistent
consistent
A,B
E
D
C
#27 Post-test
Post-Instruction
N = 299
Proportion of responses in this category virtually unchanged
Incorrect responses less consistent with other answers
![Page 46: Students Reasoning Regarding Electric Field Concepts Pre- and Post-Instruction David E. Meltzer Department of Physics and Astronomy Iowa State University.](https://reader036.fdocuments.in/reader036/viewer/2022062413/5a4d1b717f8b9ab0599b5535/html5/thumbnails/46.jpg)
Students’ Explanations Consistent Pre- and Post-Instruction [i.e., for EB,I = EB,II = EB,III]:
• Examples of pre-instruction explanations:– “they are all at the same voltage”– “the magnitude is 40 V on all three examples”– “the voltage is the same for all 3 at B”– “the change in voltage is equal in all three cases”
• Examples of post-instruction explanations:– “the potential at B is the same for all three cases”– “they are all from 20 V – 40 V”– “the equipotential lines all give 40 V”– “they all have the same potential”
![Page 47: Students Reasoning Regarding Electric Field Concepts Pre- and Post-Instruction David E. Meltzer Department of Physics and Astronomy Iowa State University.](https://reader036.fdocuments.in/reader036/viewer/2022062413/5a4d1b717f8b9ab0599b5535/html5/thumbnails/47.jpg)
Students’ Explanations Consistent Pre- and Post-Instruction [i.e., for EB,I = EB,II = EB,III]:
• Examples of pre-instruction explanations:– “they are all at the same voltage”– “the magnitude is 40 V on all three examples”– “the voltage is the same for all 3 at B”– “the change in voltage is equal in all three cases”
• Examples of post-instruction explanations:– “the potential at B is the same for all three cases”– “they are all from 20 V – 40 V”– “the equipotential lines all give 40 V”– “they all have the same potential”
![Page 48: Students Reasoning Regarding Electric Field Concepts Pre- and Post-Instruction David E. Meltzer Department of Physics and Astronomy Iowa State University.](https://reader036.fdocuments.in/reader036/viewer/2022062413/5a4d1b717f8b9ab0599b5535/html5/thumbnails/48.jpg)
Students’ Explanations Consistent Pre- and Post-Instruction [i.e., for EB,I = EB,II = EB,III]:
• Examples of pre-instruction explanations:– “they are all at the same voltage”– “the magnitude is 40 V on all three examples”– “the voltage is the same for all 3 at B”– “the change in voltage is equal in all three cases”
• Examples of post-instruction explanations:– “the potential at B is the same for all three cases”– “they are all from 20 V – 40 V”– “the equipotential lines all give 40 V”– “they all have the same potential”
![Page 49: Students Reasoning Regarding Electric Field Concepts Pre- and Post-Instruction David E. Meltzer Department of Physics and Astronomy Iowa State University.](https://reader036.fdocuments.in/reader036/viewer/2022062413/5a4d1b717f8b9ab0599b5535/html5/thumbnails/49.jpg)
Some Student Conceptions Persist, Others Fade
• Initial association of wider spacing with larger field magnitude effectively resolved through instruction– Proportion of “C” responses drops to near zero
• Initial tendency to associate field magnitude with magnitude of potential at a given point persists even after instruction– Proportion of “E” responses remains 20%
But less consistently applied after instruction: for students with “E” on #27, more discrepancies between responses to #27 and #30 after instruction
![Page 50: Students Reasoning Regarding Electric Field Concepts Pre- and Post-Instruction David E. Meltzer Department of Physics and Astronomy Iowa State University.](https://reader036.fdocuments.in/reader036/viewer/2022062413/5a4d1b717f8b9ab0599b5535/html5/thumbnails/50.jpg)
Some Student Conceptions Persist, Others Fade
• Initial association of wider spacing with larger field magnitude effectively resolved through instruction– Proportion of “C” responses drops to near zero
• Initial tendency to associate field magnitude with magnitude of potential at a given point persists even after instruction– Proportion of “E” responses remains 20%
But less consistently applied after instruction: for students with “E” on #27, more discrepancies between responses to #27 and #30 after instruction
![Page 51: Students Reasoning Regarding Electric Field Concepts Pre- and Post-Instruction David E. Meltzer Department of Physics and Astronomy Iowa State University.](https://reader036.fdocuments.in/reader036/viewer/2022062413/5a4d1b717f8b9ab0599b5535/html5/thumbnails/51.jpg)
Some Student Conceptions Persist, Others Fade
• Initial association of wider spacing with larger field magnitude effectively resolved through instruction– Proportion of “C” responses drops to near zero
• Initial tendency to associate field magnitude with magnitude of potential at a given point persists even after instruction– Proportion of “E” responses remains 20%
But less consistently applied after instruction: for students with “E” on #27, more discrepancies between responses to #27 and #30 after instruction
![Page 52: Students Reasoning Regarding Electric Field Concepts Pre- and Post-Instruction David E. Meltzer Department of Physics and Astronomy Iowa State University.](https://reader036.fdocuments.in/reader036/viewer/2022062413/5a4d1b717f8b9ab0599b5535/html5/thumbnails/52.jpg)
Some Student Conceptions Persist, Others Fade
• Initial association of wider spacing with larger field magnitude effectively resolved through instruction– Proportion of “C” responses drops to near zero
• Initial tendency to associate field magnitude with magnitude of potential at a given point persists even after instruction– Proportion of “E” responses remains 20%
But less consistently applied after instruction: for students with “E” on #27, more discrepancies between responses to #27 and #30 after instruction
![Page 53: Students Reasoning Regarding Electric Field Concepts Pre- and Post-Instruction David E. Meltzer Department of Physics and Astronomy Iowa State University.](https://reader036.fdocuments.in/reader036/viewer/2022062413/5a4d1b717f8b9ab0599b5535/html5/thumbnails/53.jpg)
Summary
• Even in the absence of previous instruction, students’ responses manifest reproducible patterns that may influence learning trajectories.
• Analysis of pre- and post-instruction responses discloses consistent patterns of change in student reasoning that may assist in design of improved instructional materials.
![Page 54: Students Reasoning Regarding Electric Field Concepts Pre- and Post-Instruction David E. Meltzer Department of Physics and Astronomy Iowa State University.](https://reader036.fdocuments.in/reader036/viewer/2022062413/5a4d1b717f8b9ab0599b5535/html5/thumbnails/54.jpg)
Summary
• Even in the absence of previous instruction, students’ responses manifest reproducible patterns that may influence learning trajectories.
• Analysis of pre- and post-instruction responses discloses consistent patterns of change in student reasoning that may assist in design of improved instructional materials.