Transcript Descriptions RROF_PERC04.ppt

Student Descriptions of Refraction and Optical Fibers
Fran
1
Mateycik ,
1Rensselaer
JJ
1
Rivera ,
DJ
Polytechnic Institute,
1,2
Wagner ,
2Grove
City College,
Study:
• Follow-up questions included “How does the fiber keep the light
from escaping?” and “What can you tell me about refraction?”
2 Physics Faculty
• ScIT students (both pre- and
post-instruction) were
interviewed via WebCT’s Chat
Room in the Spring of 2003.
3Russell
Sage College
Context:
• “What is an optical fiber and what does it do?”
• Faculty, REU students, and inservice (non-physics) teachers
were interviewed in a
traditional (face-to-face) form
in the Summer of 2002.
and Sybillyn
3
Jennings
5
Physics
Students
(REU)
5 In-Service
Teachers
22 ScIT PreInstruction
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 Piaget-style interviews to study students’
understanding of total internal reflection (TIR) and how TIR relates to the operation of optical fibers.
8 ScIT PostInstruction
Demographics of Interviewees
Conclusions:
Fiber Optic Network
Laser light trapped in a plastic fiber.
Air serves as the cladding.
Optical Fiber next to sewing needle.
The core of the fiber is 62 microns in
diameter; the cladding is 125 microns.
[1] Lillian C. McDermott, “Bridging the Gap Between Teaching and Learning: The Role of Research,” The Changing Role of Physics Departments in Modern Universities: 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,” Classroom Lessons: Integrating Cognitive Theory and Classroom Practice, ed. by McGilly (MIT Press, 1994).
[3] J. Piaget, The child’s conception of the world, 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.