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The Science of Information Technology (ScIT) introduces students of all majors to the physical principles behind the operation of information systems. NSF is supporting current efforts to make
ScIT materials useful to a large audience. As part of that effort, we are designing diagnostic questions addressing the topics covered in ScIT.
Diagnostic questions are most useful when they address student preconceptions and distinguish between different cognitive models [1]. Clinical Interviews have long been regarded as an effective means of eliciting students’ conceptual frameworks [1-3]. Piaget [3] developed the method of critical exploration to see what thoughts lay behind a child’s initial answer to a question, and the PER community has used this method extensively [1-2]. We used Piagetstyle interviews to study students’ understanding of total internal reflection (TIR) and how TIR relates to the operation of optical fibers.
• Follow-up questions included “How does the fiber keep the light from escaping?” and “What can you tell me about refraction?”
,
, and
were interviewed in a traditional (face-to-face) form in the Summer of 2002.
• ScIT students (both pre - and
) were interviewed via WebCT’s Chat
Room in the Spring of 2003.
Laser light trapped in a plastic fiber.
Air serves as the cladding.
• E-interviews can provide valuable information about cognitive models. They provide some advantages over face-to-face interviews but have their own set of limitations.
• Instructor time is smaller in e-interviews, due to decrease in transcription time; student time is greater in e-interviews.
• Several students called the e-interview “fun” or “interesting”
Optical Fiber next to sewing needle.
The core of the fiber is 62 microns in diameter; the cladding is 125 microns.
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Can be conducted from wherever, whenever, and however is convenient (at home, listening to music, eating ice cream, in jammies, etc.).
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Can hold 2 or 3 interviews simultaneously, typing questions for student 3 while students 1 and 2 are typing their responses. (4 at a time is a bit much.)
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Typed thoughts often come across more coherently than spoken thoughts.
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Interviewer does not need to worry about their gestures giving away their thoughts about the students answers.
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Apparent anonymity lets students express their lack of knowledge with less embarrassment.
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Interviewees generally created work-arounds to constraints they experienced. (drew pictures, used keyboard symbols, etc)
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Language used to convey interviewees confidence in their answer or description. (umm, I don’t reall know, I guess…, iirc,
I could take a wild stab, etc)
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Minimal transcription needed!!! (WebCT records conversations in Chat Rooms 1-4.)
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Utilize multiple communication channels. (words, gestures, tone of voice, etc)
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Substantial transcription time
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Transcription difficult to convey gestures, tone of voice.
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Scratch Pad (Draw figures, write equations, etc)
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Demonstration equipment (optical fiber)
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1 interview at a time
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Participants do not need a familiarity with internet technology
Fiber Optic Network
Face-to-Face Interviews
E- Interviews
[1] Lillian C. McDermott, “Bridging the Gap Between Teaching and Learning: The Role of Research,”
: Proceedings of
ICUPE, ed. by E. F. Redish and J.S. Rigden.
[2] E. Hunt and J. Minstrell, “A Cognitive Approach to the Teaching of Physics,”
, ed. by McGilly (MIT Press, 1994).
[3] J. Piaget,
, trans. by J. & A. Tomlinson. (Littlefield, NJ, 1926/1972).
RPI work supported in part by NSF CCLI Program under grant DUE-0089399.
Thanks as well to Leo Schowalter for access to ScIT students, and to the rest of the ScIT advisory committee: Karen
Cummings, Toh-Ming Lu, Saroj Nayak, Jim Napolitano, Peter Persans, and Wayne Roberge.