UpDate - Vol. 13, No. 14, Page 1
December 9, 1993
Consultant offers new approach to teaching

     It's Friday afternoon, and a call comes in concerning an automobile
accident that just occurred. It is a two-car collision with possible
speeding, possible running of a stop sign and a possible fatality at the
scene. Sounds like a job for the Newark police. But, this actual case was
faced and solved by the Honors Physics 201 class.
     This example, along with many others, is part of a new approach that
Barbara Duch, teaching consultant from the Center for Teaching
Effectiveness, is using to teach physics to pre-med and pre-physical
therapy majors, as well as other science students.
     Duch explained that this class is structured around a problem-based
style of learning. This method is based on the premise that students learn
concepts more effectively in connection with real-world problems.
     The class is group-oriented. The students cooperate in groups of four
to solve problems and to answer each other's questions. Group work enables
students to help one another work through the problems so that they
eventually uncover the pertinent information themselves. One or two
problems in the hour exams are solved in the group, while the remainder are
done individually.
     As many of the honors section class members are ultimately interested
in health careers, Duch said, "Many of the experiments and problems are
related to the body in one way or another."
     For example, the traditional center of gravity problem that may have
appeared on page 165 of a textbook was replaced with students actually
estimating their own centers of gravity with a book bag, placed either on
or off their shoulders. Students could then understand how the center of
gravity would shift in a person who had lost an arm or a leg.
     Duch approached the topic of acceleration in a novel way also.
Participants were assembled on the Mall and each timed a 20- meter run
while running at constant velocity versus accelerating from a stand-still
position. The class also rode the elevators in Christiana East to observe
and record changes in their weight as the elevator accelerated upward and
downward.
     Students also visited the Sports Science Laboratory where they saw an
EKG performed. With this experiment, students gained a clearer
understanding of the electrophysiology of the heart.
     The laboratory and classroom are no longer the only homes for physics
experiments as students also worked on a heat problem derived from the
popular movie, The Wizard of Oz. The scene in which Dorothy douses the
Wicked Witch with water as the latter cries, "I'm melting, I'm melting," is
easily remembered. What is not so readily recognized is, although the witch
says she is melting, one sees steam.
     Duch then posed this question to the class: "Is the witch subliming,
vaporizing or really melting?" After students decided she was indeed
melting, they then attempted to determine her latent heat of fusion. To
solve this problem, they estimated the amount of water in a bucket and they
then determined how much energy the water had given the Wicked Witch to
melt her. The latent heat of fusion was eventually calculated to be so low
that the witch could not have been human; that is, she was composed of some
material other than flesh.
     Duch also aims to connect all of the concepts. "I want to help
students see how it all fits together. Experts know this, but novice
students don't."
     The project that effectively linked equations of motion and energy
with those of friction and momentum was the automobile accident. An actual
police accident report provided the problem solvers with sketches of an
accident scene prior to and after impact. The diagram included the weight,
initial direction and paths of the cars and the skid marks of one car after
the accident. With this information, it was up to each group to determine
if one of the cars was speeding or if the other had run a stop sign. All
six groups came to the conclusion that, indeed, one of the drivers had run
a stop sign.
     Duch said she does not take a structured laboratory approach in the
class. "There are no set patterns," she said, "and students must look at
problems from different perspectives." She also discussed the idea of the
abstract and the concrete. "It is easiest to apply something you've seen
and already understand to the abstract."
     Duch will continue to teach this class through the spring semester,
and then will return to her full-time position at the Center for Teaching
Effectiveness (CTE).
     One of Duch's responsibilities at CTE is working with other faculty
who are incorporating some aspects of problem-based learning in their
courses. In the last 18 months, over 80 faculty have attended several
problem-based learning workshops sponsored by CTE. Currently, seven faculty
who are using "real world" problems and group approaches to teach physics,
chemistry and biology are meeting regularly to share their experiences with
this method in their own classes and to discuss ways of expanding this
technique to large classes. One of these faculty, David Onn from the
Physics and Astronomy Department, is using groups in the regular section of
Physics 201 with 180 students. Onn also tests students in groups as well as
individually.
     For students, the innovative approach works. Chad Kessler , a pre-med
sophomore, said, "It's really neat to see practical applications of physics
in the real world. I especially like it because it is aimed for those going
into the medical field."
                                                  -Jennifer Jones