Biological - NIH Office of Science Education - National Institutes of ...

Sleep, Sleep Disorders, and Biological Rhythms
Content Standard A:
Design and conduct
scientific investigations.
Content Standard A:
Communicate and
defend a scientific
argument.
results in later bedtimes.
• People go to bed earlier in the winter months.
• Snoring is associated with more frequent awakenings during
the night.
Students are limited by their imagination, but their hypotheses must
be answerable using the available data.
4. After the class has had the opportunity to test their hypotheses, ask
for a volunteer to report his or her hypothesis and findings. Ask the
student why he or she chose that hypothesis.
Make sure that students are testing hypotheses that can be investigated
using the available data.
5. If a student isn’t sure that the data support the hypothesis, ask why
and consider what additional data could help resolve the question.
Even if the student has asked an appropriate question of the database,
there may be too few entries to reach a firm conclusion. The
database can address questions regarding the effects of gender, snoring,
and caffeinated drinks but does not contain information to
address other variables such as the effects of dreaming, allergies, or
physical exercise.
This is an opportunity to discuss what types of data are needed to
properly evaluate a hypothesis.
6. As time permits, ask other students to report their hypotheses and
findings. Try to elicit different hypotheses.
Assessment: Instruct
students to write a
brief report that states
their hypothesis, the
data from sleep diaries
used to test it, and
their conclusions. If
the data do not support
a firm conclusion,
instruct students to
explain what additional
information
would be needed to
reach a conclusion.
To enrich the discussion, encourage students to ask questions and
challenge the conclusions of the presenters.
7. To conclude the activity, explain to the class that people feel pressure
to sleep in daily cycles. Scientists refer to this need-to-sleep
cycle as “homeostatic regulation.” Ask students to draw a graph
that depicts the need to sleep (on the y-axis) versus the time of day
(on the x-axis).
Students should conclude that the need to sleep increases throughout
the day, reaching some level that is sufficient (in combination
with other factors) to induce sleep. Sleep itself causes a decline in
the need to sleep. This is depicted in Figure 1.2.
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