51.Your friend Carrie took a daily supplement of vitamin C : 1401514.
51.Your friend Carrie took a daily supplement of vitamin C for a week following the first signs of a cold and stated that she felt a lot better. Which of the following best describes her experience?
b.a blind experiment
c.a human intervention trial
d.a case-control experience
52.In the scientific method, what is the name for a statement such as the following? “The researchers anticipate that more of the variation in body weight will be explained by diet than physical activity.”
b.the placebo effect
53.Among the following, which is the major weakness of a laboratory-based study?
a.The costs are usually high.
b.It is difficult to replicate the findings.
c.The results cannot be directly applied to human beings.
d.Experimental variables cannot be easily controlled.
54.Who are the subjects in a clinical trial?
a.tissue cells in culture
b.rats, mice or other experimental animals
c.individual human beings
d.populations of human beings
55.What is the meaning of a double-blind experiment?
a.Two groups of subjects take turns getting the control or experimental treatment.
b.Neither subjects nor researchers know which subjects are in the control or experimental group.
c.Subjects know whether they are in the control or experimental group, but the researchers do know.
d.One group of subjects receives placebo treatment twice.
56.What is the benefit of using controls in an experiment?
a.The subject group size can be very large.
b.The subjects do not know anything about the experiment.
c.The subjects who are treated are balanced against the placebos.
d.The subjects are similar in all respects except for the treatment being tested.
57.What is the benefit of using placebos in an experiment?
a.All subjects are similar.
b.All subjects receive a treatment.
c.Neither subjects nor researchers know who is receiving treatment.
d.All subjects will feel some improvement.
58.Research has found that countries across the world with higher dietary fibre intakes have lower rates of some chronic diseases. Which of the following types of studies does such research refer to?
c.human intervention trials
59.What is the benefit of using a large sample size in an experiment?
a.Chance variation is ruled out.
b.There will be no placebo effect.
c.The experiment will not need to be double-blind.
d.The control group will be similar to the experimental group.
60.In a study of the effectiveness of vitamin C in reducing the incidence of colds in grade 6 students,, a researcher plans to distribute all the vitamin C pill bottles to the girls and all the placebo pill bottles to the boys. What should the researcher do differently?
a.He should allow the girls and boys to choose whether they want the vitamin C or placebo pills.
b.He should distribute the bottles randomly, and then tell the students what they are getting.
c.He should have students randomly choose the bottles but not tell him what group they received until the end of the study.
d.He should arrange that neither he nor the students knows the contents of the randomly distributed pill bottles.