As society changes, so does the next generation's exposure to the variety and
complexity of diseases in the world. The anthrax scares of 2001 alerted
students across our nation to how an individual can become infected with a
disease, but also led to questions concerning why everyone did not become
infected. Advertisements bombard our students, filling their minds with small
bits of information regarding their body's need for prescription drugs, but
this information is disconnected from an understanding of how an individual's
immune system works or how a disease is contracted. As a result, our students
are forming opinions based on marketing techniques and not scientific facts or
research.
To address this issue, Champlain Valley Union High School in Hinesburg, VT
began offering a semester long class geared mainly towards sophomores entitled
Introduction to Human Biology. The course was designed around Vermont Framework
of Standards 7.14 and seeks to "introduce students to heredity, body systems,
and individual development." The course is broken into units based on the 10
body systems and the study of human genetics. When designing the course,
department faculty reviewed several textbooks and ultimately decided upon
Modern Biology by Towle, which is also used in the ninth grade program.
As one of the designers of the course, I use the book quite extensively in the
classroom, helping students decipher the language of biology as they learn
about their body systems. However, I have become increasing critical of the
chapter on the Immune System after using it in several semesters worth of
classes. As a result of the book's limitations, I began pondering new methods
to use when teaching the immune system. To that end I developed an action
research project aimed at creating and assessing a new immunology unit which
integrates systems thinking via STELLA computer modeling in order to help
students think holistically about disease. Through systems thinking and STELLA
I could give my students a broad overview of how their immune system operates
and how it relates to systemic issues such as communicable diseases and
vaccinations.
My revised immunology unit consisted of the following activities: a two part
in-class lecture on the human immune response that consisted of traditional
note taking and the use of two STELLA models shown to the students via a
projector and a student handout.(Part one of my human immune response lecture
consisted of the Nonspecific Immune Defenses and the start of the Specific
Immune Responses, ending with B and T cell production. Part two picked up with
B and T cell production using a STELLA model, then discussed the cell mediated
and humoral immune responses using first a STELLA model and then traditional
note taking.) A second lecture followed discussing how diseases are spread
through a population, transmission rates for diseases, and how a person can
become naturally immune to a disease and acquire immunity through exposure and
vaccinations.
Two lab activities followed the lectures. The first was a communicable disease
lab entitled NERDS: New England Regional Disease Syndrome. This imaginary
disease spread through our class using one infected individual, handshakes, and
transmission rate probabilities. From the lab, the class was able to create a
STELLA model depicting relationships between different variables as the disease
spread through the class. The second lab examined communicable diseases and
vaccinations in a population. After reviewing the STELLA model from the
previous lab with the class, laptop computers were given to pairs of students
with a pre-built model. The flight simulator allowed students to change the
data for each variable finding "tipping points" for different variables the
simulation.
I evaluated the success of the unit based on three surveys. While I was unable
to find any relevant conclusions when comparing the pre-unit and post-unit
surveys, I did receive very interesting feedback from the overall unit
questionnaire. Students had strong reactions to about the using and
understanding of the STELLA model in the lecture. The majority of the students
felt the models added to the lecture notes, but preferred when I gave note
first and then showed the model. This allowed them to make direct connections
to the model structure. When I showed the model first and then gave notes, one
student remarked in their survey, "I had forgotten all the pathways by the time
I got all the notes written down." Based on their feedback I will utilize the
storytelling feature next year.
Overall I was very pleased with the outcome of this unit. Students were engaged
in the activities, and the models improved their understanding of the human
immune system. The students' feedback is invaluable as I modify this unit and
plan for the implementation of Systems Thinking and STELLA into other units.
