4. Variables
• Explanatory: the amount of time subjects
waited after eating the hamburger (a half
hour vs. an hour)
• Control: the brand/type/portion
size/preparations of the hamburger and the
amount the subjects swam for (15 minutes)
• Response: how the subjects’ stomachs felt
(symptoms) after swimming
5. Blocking
• Blocking will be used between the gender of
the children due to the possible differences
between digestive systems.
• To reduce bias and variability
6. Randomization
• Alphabetize males and females separately according to their last names
• Beginning with the first alphabetized name on the female name list assign
numbers from 1-25
• Use RandInt on calculator (TI-84) to generate 25 random numbers
• Ignore repeats
• These 25 females(corresponding to the numbers that were generated) will
be assigned to the first treatment, while the other 25 females will be
assigned to the second treatment (who’s numbers were not generated)
• Repeat steps for males
7. Treatments
Treatment 1
• Subjects will receive one
hamburger per child and
digest/wait for exactly a
half hour, and then swim
for exactly 15 minutes
Treatment 2
• Subjects will receive one
hamburger (prepared
exactly the same as the
hamburgers in treatment 1)
per child and digest/wait for
exactly an hour, and then
swim for exactly 15 minutes
8. Blinding
• Blinding will be used so that the
EVALUATORS will NOT be aware of what
treatments the subjects are receiving
• This strategy will prevent bias in the
experiment
• However, the subjects will be aware of what
treatments they are receiving
9. Possible Concerns
• “Be Aware of The Lurking Variable”: the
children may feel symptoms due to the
actual hamburger and not from
swimming after eating
10. Results
• Ask children how their stomach feels on a scale of 1
to 10 (1 representing a bad feeling and 10
representing a good feeling) directly after they eat
the hamburger, but before they swim
THEN….
• Ask children how their stomach feels on a scale of 1
to 10 (1 representing a bad feeling and 10
representing a good feeling) after they finish
swimming for 15 minutes
11. Conclusion
• Compare the children’s stomach symptoms after eating the
hamburger, without swimming, to the children’s symptoms
after eating the hamburger and swimming for 15 minutes
• Possible conclusion drawn from experiment: One may
assume that the children who waited exactly an hour after
eating the hamburger, and swam for 15 minutes, would
describe that their stomach felt good, without any
symptoms.
