Activity
1. At the beginning of class remind students of
the article, “Does sunlight cause skin cancer?” which
they read during one of the stations of the explore lesson,
Sun, Skin and Cancer.
2. Elicit from the students the main points covered
in the article. Encourage them to point out that
there are
different types of light, the exposure to which can
cause different ill effects to skin. Students
should also point
out that these negative effects can be prevented in
a number of ways- by reducing the amount and
type of UV
that the skin is exposed to- through materials, sunscreens,
and other products.
3. Explain to the students that they should draw upon
that reading to develop an investigation where they
test the effectiveness of certain products to reduce
the effects
of UV rays.
Tell them, “First you will design non-human
experimental trials to test a question of your choosing,
and then design a human clinical trial. At the front
of the room there are a number of materials with which
you can design your experiment; the only requirement
is that you must be testing these materials in response
to UV light.” There should be sunscreens of different
SPF levels and different sunscreens with the same SPF
level as well as sunless tanning lotions, white and black
material, plastic wrap and glass, polarizing and non-polarizing
sunglasses, plus lip balms with and without SPF. There
will be UV-light generating lamps, as well as access
to the outdoors and fluorescent and incandescent lamps.
UV reactive Frisbees will be used as indicators of UV
blocking.
4.
Students will (in groups) use the Designing
an Experiement and Writing a Hypothesis handout to record their question,
their prediction and hypothesis as well as a method or
protocol
for their
experiment.
5. On the second day, students will conduct their
experiment. When they have completed the experiment
they will write
their results. It would be useful to have a digital
camera on hand to take pictures, as the results
are likely to
be qualitatively visual.
6. As they finish, have students clean up their
areas and brainstorm, as a group, on any questions
that
their experiment raised that could be answered
with human
trials. Have them, as a group, identify one
of these research
questions that they might like to address and
what the objective of this study will be. (i.e. “We want
to address whether brand name sunscreen A (SPF 15) works
as well as generic sunscreen B (SPF 15) at blocking the
effects of UV rays from the sun on human skin, with the
objective to see effectiveness versus price”).
Subject selection (day 3):
7. Ask the class “What are some reasons why some
people should be excluded from a study? Are there certain
people who are riskier to have in a study than others?
Why? How homogeneous should your study group be? Does
this depend on your question? How does the homogeneity
of your study group affect the study size? What reasons
are there to limit the number of subjects in your study?
What reasons are there to increase the number of subjects?”
8.
When the class has considered these questions, have them
individually come
up with a list
of exclusion and inclusion criteria for
their particular
study.
9.
Then have each research group get together and pool their
ideas and write
a common
inclusion and
a common
exclusion criteria for their study.
10. Each group will then receive a
handout with a list of potential
subjects, and
they will choose
appropriate
subjects for their study (indicated
by a check next
to the included subjects) and a reason
why each excluded patient was excluded,
based
on their
exclusion criteria.
11. Each group will then identify
(if desired) additional criteria
for exclusion
that
they may have identified
by assessing the provided subjects.
12. Then tell students that for
their clinical trial, they MUST
have 14
subjects from
this list. If they
have more, who do they now exclude?
If they have fewer, who
do they now include?
13. Ask the class to generate
a list of exclusion criteria
(you
will only
do this
for now (??))-
taking note on
the board of when there are
ones common to multiple groups.
14. Then ask the class: “Which groups had not excluded
enough subjects? What did you use as extra criteria for
exclusion? Which groups had excluded too many? What criteria
did you use to include some subjects you had already
excluded? What might these decisions mean for your results?
Do you feel what you did was appropriate? If not, what
would you, if you were a researcher in this position,
do differently?”
Treatment selection (day
4):
15. Now that students have
their included subjects,
they will
be asked to divide
them into their
treatment groups.
Each research group should
identify the treatment
groups they have
and how they
are assigning
subjects to each
treatment. They should
identify, in writing,
how the way they
assigned treatments
will achieve their
stated
research objective. (random
vs. matched)
Poster creation (days
4-6):
16. Student research
groups will then
be responsible for creating
a “Human Clinical Trial” addition
to their poster. These posters must include:
a. Results from their
pre-clinical experiment
b. Clinical proposal
(research question,
objective, rationale
and treatments)
c. Inclusion criteria
d. Exclusion criteria
e. Predictions
17. Posters should
be ~60% from a,
with the
remaining
40% from
b-e.
Museum Walk (day
6): 18. Students will
place posters
around the
room and take
turns standing
by their poster
as the
other
students in the
group rotate
through the
other posters.
Closure
Have students respond to the following in their science notebook: “In
what way do our lessons on the physiology of skin, our survey of recent research
of skin cancer issues and our creation of a clinical trial address Environmental
Health?” Have them also write their own definition of “Environmental
Health”. Discuss their answers as a class.
Homework
Throughout
the week, students will work on their questions, methods, and
poster presentation both in class and at home. |
