Lillian C. McDermott
15
History
3/15/10
lens, there would be no image.
Just 20% predicted correctly that blocking half of the lens
would affect only the brightness, but not the extent, of the image.
About 40% realized that
moving the screen toward the lens would cause the image to disappear.
Only 25%
understood that without the screen there would still be a real image at the same location.
(Percentages have been rounded to the nearest 5%.)
Many of the students did not relate
the thin lens formula to the physical situation.
Neither did they understand that a diagram
of the three principal rays is only an algorithm (a set of rules) for locating the image.
When multiple-choice versions of the first three questions were given to more than
200 students in introductory physics, the results were similar.
In the papers in
AJP
and
The Physics Teacher
cited above,
we identified student difficulties with the refraction and
reflection of light by lenses and mirrors.
These findings guided the development of the
Light and Optic
s module in
PbI
and helped motivate a later study in geometrical optics.
35
Converging Lens Tasks.
While at UW, Fred also began to explore student understanding of physical optics,
but his two-year visit with our group was too short for an in-depth study.
After joining the
faculty at San Diego State, Fred became a leader at its Center for Research in Mathematics
and Science Education (CRMSE).
He has drawn on his research and made innovative use
of computers to produce excellent instructional materials for K-12 teachers and students.
36
35
See Ref. 59.
36
See, for example, F.M. Goldberg, P. Heller
et al., Constructing Physics Understanding
(The Learning
Team, Armonk, NY), and F.M. Goldberg, S. Robinson, V. Otero, and N. Thompson,
Physics and
Everyday Thinking
(It’s About Time, Inc., Armonk, NY.)
Lillian C. McDermott
16
History
3/15/10
Our papers on geometrical optics inspired David Sokoloff (U. of Oregon) to
develop new materials for
Real Time Physics (RTP)
and
Interactive Lecture
Demonstrations
(ILDs).
37
David designed an
ILD
to show that a bulb produces a
diverging beam of light (not just the three principal rays), part of which passes through the
entire
exposed area of the lens.
Thus, any part of the lens produces an image of the whole
bulb.
Use of this
ILD
in only one lecture resulted in a much greater learning gain.
38
In 1983 Diane Grayson, my fifth graduate student, came from South Africa.
She
explored the utility of computer simulations to probe student reasoning.
Although the
results were not always the same as with real equipment, she found that the difficulties
were similar.
Her dissertation (1990) and a related paper in
AJP
describe this research.
39
The 1983 International Workshop on Research in Physics Education at La Londe
les Maures, France, made a deep impression.
40
I met several physicists and science
educators who were examining student learning.
Laurence Viennot (U. of Paris VII) was
one of the few working at the university level.
41
Others were Audrey Champagne (then at
U. of Pittsburgh) and Fred Reif (then at UC, Berkeley), whose research on problem-
solving had impressed me.
42,43
Audrey and I had met before because of a mutual
commitment to teacher education.
After the Workshop, Audrey, her mother, and I
traveled together.
Our visit to Omaha Beach had a profound effect on me.
37
D.R. Sokoloff, P.W. Laws, and R.K. Thornton,
Real Time Physics: Active
Learning Laboratories,
Module 4: Light and Optics
(John Wiley & Sons, Inc., Hoboken, NJ, 2004), and D.R. Sokoloff and R.K.
Thornton,
Interactive Lecture Demonstrations
(John Wiley & Sons, Inc., Hoboken, NJ, 2008).
38
See
Active Learning in Optics and Photonics Training (ALOP) Manual,
D.R. Sokoloff, Ed.,
UNESCO, Paris, 2006.
The manual is used in international workshops for developing countries.
39
D.J. Grayson and L.C. McDermott, “Use of the computer for research on student thinking in physics,”
Am. J. Phys,
64
(5), 557 (1996).
40
The 1983 La Londe Workshop was organized by Goéry Delacôte (U. of Paris VII) and Andrée
Tiberghien (
CNRS
).
(
CNRS
is the French acronym for Centre National de la Recherche Scientifique.)
41
L. Viennot, “Spontaneous Reasoning in Elementary Dynamics,”
Eur. J. Sci. Educ.
1
(2), 205
(1979).
42
A. B. Champagne,
L.E. Klopfer, and J.H. Anderson, "Factors influencing the learning of classical
mechanics,”
Am. J. Phys.
48
(12), 1074 (1980).
43
Fred Reif used physics as a context to examine problem-solving and issues in cognitive science.
See F.
Reif,
Applying Cognitive Science to Education
(The MIT Press, Cambridge, MA, 2008) and Ref. 75.
