Notes for Instructors |
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Here are some ideas on how to use Epidemiology in the classroom and laboratory. First we describe a series of activities used in a freshman seminar class at the University of Oregon. Instructors should feel free to modify these materials to suit their needs. We then describe how instructors can take advantage of some of Epidemiology's features to help prepare learning materials.
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The Simple SIR Model |
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How we use Epidemiology at the University of Oregon |
The sample learning module was designed for
use in introductory classes for non-majors. The module was used in Winter 1996 and
1997 by Dan Udovic in a freshman seminar. By the time students used the learning
module in the seminar, they had been learning (in a very non-technical way) about
the spread of infectious diseases for several weeks. They had been reading and discussing
Laurie Garrettís The Coming Plague, and had seen videos on the eradication
of smallpox and on issues surrounding the use of polio vaccines.
To learn more about this course and the resources used, you may want to check out
the class World
Wide Web site.
Before introducing the students to the computer program, you might consider either
or both of the following activities to lay the groundwork. For more advanced biology
majors these activities may not be important. For most non-majors, however, the activities
prepare them for the computer exercises which follow.
The first is a simple hands-on classroom simulation activity that illustrates how
an infectious disease spreads. The general idea is that one or two students in a
class are somehow "infected" and infect other students through a series
of contacts. No one knows which students were infected originally, so the problem
is for the class to try to deduce the index case(s) from information that they collect
about their contacts. There are many variants of this exercise, but a simple, effective,
and fun lab exercise is described by Dickey (1989; American Biology Teacher 51(6)
364-365). The whole exercise can be done in 30-40 minutes. Once the exercise is complete,
the instructor can work with the class as a whole and develop a graph of the number
of susceptible and infected individuals through time.
A second preparatory activity is to have students (working in groups) develop a flow
chart or concept map describing the relationships between factors that influence
the spread of a disease. Butcher paper, magic markers and post-its can be provided
as materials. Finished diagrams can be presented to the whole class for discussion.
If students have worked on their diagrams individually (e.g., as a homework assignment
before class) they will be prepared to make more rapid progress as a group. Their
diagrams can form the springboard for a discussion of various proximate and ultimate
causes of disease outbreaks, and for an introduction to the flow chart models used
in Epidemiology.
The sample activity move from simple and highly structured to more complex and open-ended.
We encourage this approach, since it eases students into the program, building both
confidence and understanding. As we help students through the structured exercises,
we try to avoid "leading" students to the "right answer". Rather,
we try to help them understand their observations, clarify their thinking, and design
good experiments. Furthermore, whenever possible, we have students take the time
to think about what they expect to happen (usually in small groups), to write down
predictions, and to explain the basis for their predictions. Often comparing the
results that they obtain with their predictions leads to cognitive dissonance which
can be very useful in the learning process.
Initially some students may feel that this is a glorified game of "hide and
seek" (in a sense it is). In addition, though, it is essential practice for
open-ended investigations, and the interaction between faculty and student is much
more rewarding than when guiding students through prescribed steps that lead to the
"correct answer". Students develop a deeper understanding of the concepts
and gain important skills in designing and performing experiments, and faculty gain
important insights regarding student knowledge and misconceptions.
The sample activity introduces students to the following concepts:
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Open-ended Investigations with Epidemiology |
Once students have worked through those activities, they will be ready to use
Epidemiology to build and analyze models of particular diseases of their own
choosing. They might be asked to find literature and materials on the Internet to
help them decide how to build their model and what values to use for various parameters.
Does their disease have a latent period, or an asymptomatic infectious stage? How
is it transmitted, and what are the probabilities of transmission? And so on. They
could be looking at diseases of humans, or of other animals, or even plants. Based
on their findings, they could be asked to prepare a report for the class. Combining
these modeling activities with a more complete study of a disease, including elements
such as the impact of a disease in human history, related scientific discoveries,
such as treatments or vaccines, and their associated controversies, could make an
excellent term-long project. In the terminology of the BioQUEST Consortium,
students would be posing their own problems, investigating possible solutions, and,
in their classroom presentations, persuading their peers.
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