Does the use of cell phones lead to a higher incidence of brain cancer? People with brain cancer were matched with people who did not have brain cancer on age, gender, and living environment. Each participant in the study was asked to answer questions about previous life experiences and exposures. Determine whether or not each of the following terms applies to this observational study.
a. prospective
b. retrospective
c. case-control study
5. A study involving ten people wants to compare the effectiveness of two different brands of antihistamines with regard to enhancing sleep. Each person is randomly assigned to take either Antihistamine A or Antihistamine B on the first night. Then each takes the other antihistamine on the following night. With each person, the hours of sleep were recorded for each night. Explain whether each of the following terms applies to this study.
a. observational study
b. randomized experiment
c. carry-over effect (confounding)
d. matched pairs (dependent samples)
e. explanatory variable (What is it?)
f. response variable (What is it?)