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Assignments PHM2612
Module 11. Experimental Studies
Complete this quiz on Canvas by or before the due date on the course calendar. Please note
that you will only have one attempt to complete the quiz; however, there is no time limit. You
may use this document to answer the questions prior to submitting your answers on Canvas.
(100 points)
1. If a vaccine has an efficacy of 95%, it means that only 5% of the vaccinated group will have
disease. (2 points)
A. True
B. False
2. The use of a placebo-controlled experimental study always results in the masking of study
subjects from study investigators. (2 points)
A. True
B. False
3. In a typical experimental randomized trial, the exposure of interest is controlled by the
investigator and not the study subjects. (2 points)
A. True
B. False
4. The smaller the sample size, the less effective randomization may be. (2 points)
A. True
B. False
5. A group of researchers wants to investigate three different risk factors for a disease. Which
of the following designs would be best? (2 points)
A. Factorial designed trial
B. Crossover trial
C. Parallel trial
D. Quasi-experimental study
, 2
6. If a study is said to have good internal validity, the results are representative of the general
population. (2 points)
A. True
B. False
7. Researchers utilize __Stratified__ randomization to ensure two comparison groups (e.g.,
receiving +/- intervention) are comparable in terms of a specific factor (e.g., sex and race).
(1 point)
8. If an investigator measures the outcome prior to and after an intervention in non-
randomized study groups, which of the following designs will that study follow? (2 points)
A. Experimental
B. Observational
C. Quasi-experimental
D. Cross-sectional
9. Choose which of the following are reasons to randomize. Check all that apply. (2 points)
☐ To control for confounding even by unmeasured or unknown factors.
☐ To ensure the effect of the intervention on the outcome is most likely attributable to the
intervention itself and not attributable to other factors.
☐ To rule out self-selection of subjects into the treatment and placebo groups.
☐ To ensure that each individual in a population has an equal chance of being selected into
the study.
Assignments PHM2612
Module 11. Experimental Studies
Complete this quiz on Canvas by or before the due date on the course calendar. Please note
that you will only have one attempt to complete the quiz; however, there is no time limit. You
may use this document to answer the questions prior to submitting your answers on Canvas.
(100 points)
1. If a vaccine has an efficacy of 95%, it means that only 5% of the vaccinated group will have
disease. (2 points)
A. True
B. False
2. The use of a placebo-controlled experimental study always results in the masking of study
subjects from study investigators. (2 points)
A. True
B. False
3. In a typical experimental randomized trial, the exposure of interest is controlled by the
investigator and not the study subjects. (2 points)
A. True
B. False
4. The smaller the sample size, the less effective randomization may be. (2 points)
A. True
B. False
5. A group of researchers wants to investigate three different risk factors for a disease. Which
of the following designs would be best? (2 points)
A. Factorial designed trial
B. Crossover trial
C. Parallel trial
D. Quasi-experimental study
, 2
6. If a study is said to have good internal validity, the results are representative of the general
population. (2 points)
A. True
B. False
7. Researchers utilize __Stratified__ randomization to ensure two comparison groups (e.g.,
receiving +/- intervention) are comparable in terms of a specific factor (e.g., sex and race).
(1 point)
8. If an investigator measures the outcome prior to and after an intervention in non-
randomized study groups, which of the following designs will that study follow? (2 points)
A. Experimental
B. Observational
C. Quasi-experimental
D. Cross-sectional
9. Choose which of the following are reasons to randomize. Check all that apply. (2 points)
☐ To control for confounding even by unmeasured or unknown factors.
☐ To ensure the effect of the intervention on the outcome is most likely attributable to the
intervention itself and not attributable to other factors.
☐ To rule out self-selection of subjects into the treatment and placebo groups.
☐ To ensure that each individual in a population has an equal chance of being selected into
the study.
