500 câu trắc nghiệm Kinh tế lượng – 1C

Identify the type of observational study.

14) A town obtains current employment data by polling 10,000 of its citizens this month.
○ Prospective
○ Retrospective
● Cross-sectional
○ None of these

Identify which of these types of sampling is used: random, stratified, systematic, cluster, convenience.

15) A market researcher selects 500 drivers under 30 years of age and 500 drivers over 30 years of
age.
○ Cluster
○ Systematic
● Stratified
○ Random
○ Convenience

16) A researcher interviews 19 work colleagues who work in his building.
○ Stratified
○ Random
○ Cluster
○ Systematic
● Convenience

SHORT ANSWER.

Write the word or phrase that best completes each statement or answers the question. Provide an appropriate response.

17) Describe a double blind experiment and explain why blinding is used. Define the term “placebo effect” as part of the answer.

A double blind experiment is one in which neither the subjects nor the researchers know who is getting the treatment. Blinding is when the subject does not know whether he or she is receiving a treatment or a placebo. Blinding is used to counteract the placebo effect in which an untreated subject believes he or she is receiving a treatment and reports an improvement in symptoms due to this belief.

18) Define observational study and experiment. Define the terms “treatment group” and “control group” as part of your answer.

In an observational study, we observe and measure specific characteristics, but we don’t attempt to manipulate or modify the subjects being studied. In an experiment we apply some treatment and then proceed to observe its effects on the subjects. In the experiment, the group receiving the treatment is called the treatment group. The control group is the group that is not given the treatment.

This is cluster sampling. The sample obtained will not be a simple random sample of all high school teachers in the district because different samples have different chances of being selected due to varying numbers of teachers in different schools.

19) A researcher obtains a sample of high school teachers in his school district by randomly selecting 10 high schools and interviewing all the teachers at each of these 10 schools. What kind of sampling is being used here? Will the resulting sample be a simple random sample of the population of teachers in the school district? Explain your thinking.

20) Explain what is meant by the term “confounding” and give an example of an experiment in which confounding is likely to be a problem.
Confounding occurs in an experiment when the effects of two or more variables cannot be distinguished from each other.

Examples will vary.