chapter 5 MINUS 18 Flashcards
- Which of the following is a property of a confounding variable?
a. It is related to the explanatory variable; individuals who differ on the explanatory variable are also likely to differ on the confounding variable.
b. It affects the response variable.
c. Its effect on the response variable cannot be separated from the effect of the explanatory variable on the response variable.
d. All of the above
D
- What does randomization mean in terms of experiments?
a. Each of the experimental units is randomly selected to participate.
b. Each of the experimental units is randomly assigned to a treatment.
c. The researchers randomly select which treatments they will include in the experiment.
d. None of the above.
D
- Which of the following is not true about placebos?
a. Placebos can be very effective in producing a response.
b. Placebos are only useful if the subject is blind as to whether or not they receive one.
c. Participants assigned a placebo are part of the control group of an experiment.
d. All of the above are true statements.
D
- Which of the following statements is true?
a. A placebo can have a strong effect on experimental outcomes because the power of suggestion is somehow able to affect the result.
b. Participants in an experiment tend to respond differently than they otherwise would, just because they are in an experiment.
c. The expectations of an experimenter can really influence the results.
d. All of the above.
D
- It is the purpose of what type of study to find out whether one or more explanatory variables are related to a certain disease (for example whether smoking causes lung cancer)?
a. Case-control study
b. Matched-pairs experiment
c. Block design
d. None of the above
B
- Which of the following statements about case-control studies is false?
a. Case-control studies have some clear advantages over randomized experiments.
b. A properly designed case-control study does a good job of reducing potential confounding variables.
c. Any controls that are selected will improve the quality of the results of the study.
d. None of the above.
B
- Which of the following describes an experiment?
a. Create differences in the explanatory variable and then examine the results.
b. Observe differences in the explanatory variable and then notice whether these are related to differences in the response variable.
c. Both a) and b) are experiments.
d. Neither a) nor b) are experiments
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- What is the effect of recruiting volunteers to participate in a randomized experiment?
a. The results will be more credible because people who really wanted to participate took part in the study.
b. The results cannot necessarily be extended to the larger population.
c. There will be no effect because the people are always randomly assigned to treatments, eliminating any type of bias.
d. Researchers are never allowed to use volunteers to participate in an experiment.
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- Which of the following defines what is meant by a control group in an experiment?
a. A group that is handled identically to the treatment group(s) in all respects except that they are controlled to a greater extent than the other groups, providing baseline data.
b. A group that is used by researchers to monitor how the experiment is going.
c. A group that is handled identically to the treatment group(s) in all respects except that they don’t receive the active treatment.
d. None of the above
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- Which of the following is implemented in an experiment to reduce unknown systematic biases due to confounding variables that might otherwise exist between treatment groups?
a. Randomization
b. Blocks
c. Repeated measures
d. All of the above
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- Which of the following is implemented in an experiment to reduce known sources of natural variability in the response variable, so that differences due to the explanatory variable can be detected more easily?
a. Matched-pairs
b. Repeated measures
c. Blocks
d. All of the above
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- Which of the following influences on the experimental units can bias the results of an experiment?
a. Placebo effect
b. Hawthorne effect
c. Not being blinded
d. All of the above
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- Which of the following describes an experiment with little or no ecological validity?
a. An experiment that is harmful to the environment and can’t be justified.
b. An experiment whose results are not ecologically beneficial.
c. An experiment whose variables are measured in an artificial setting and whose results do not accurately reflect the real world.
d. None of the above.
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- Which of the following is a potential complication of a poorly designed/conducted experiment?
a. Confounding variables
b. Interacting variables
c. Hawthorne effect
d. All of the above
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- In order to establish a connection between an explanatory and response variable in an observational study, what is needed?
a. Statistical methods that examine the connection.
b. A comparison to determine if changes in the explanatory variable are related to changes in the response variable.
c. Either a) or b)
d. You can never establish a connection between an explanatory and a response variable without doing a randomized experiment.
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