Exam 7: Sampling: Estimating the Frequency of Behaviors and Beliefs

Dr. Parrett is a sports psychologist for a large Southern university. The provost and chancellor have asked him to examine the relationship between athletic performance and academic stress at the university. For example, is it the case that the most talented athletes experience the greatest concern over their grades? The provost and chancellor have made it clear to Dr. Parrett that they want a large amount of external validity in the study. He has valid and reliable measures of both athletic performance and academic stress. He knows that he does not have the time or the money to study the entire population of interest. What is the difference between a cluster technique and a multistage technique? Explain why Dr. Parrett would be advised to use a cluster or a multistage technique rather than a simple random sample.

Having a representative sample is most important in which of the following example claims?

Which of the following sampling techniques would you recommend to a researcher interested in studying rare individuals, like people who have been struck by lightning?

Professor Kramer has decided to measure how happy his students are with his teaching this semester. He is teaching two classes this semester-Psychology and Law and Introduction to Neuroscience. He gives his students a survey. What is Dr. Kramer's likely population of interest?

Which of the following may lead to a biased sample?

Which of the following does NOT result in a biased sample?

Professor Kramer has decided to measure how happy his students are with his teaching this semester. He is teaching two classes this semester-Psychology and Law and Introduction to Neuroscience. He gives his students a survey. Dr) Kramer plans to give his survey only to his Psychology and Law students because he sees them on Mondays, Wednesdays, and Fridays and he can spare the class time (unlike in his Introduction to Neuroscience class, which only meets on Tuesdays and Thursdays). Which of the following is true?

Which of the following is necessary for a sample to be considered representative?

Dr. Dowling is a clinical psychologist who is interested in the link between mental illness and criminal activity. She gets IRB permission to study patients at all five inpatient/residential mental health facilities in her state. There are 4,307 patients currently living in these facilities. She asks patients whether they have ever been arrested for a crime and whether they have ever been convicted of a crime. She collects a sample size of 1,369. She finds that 27% (+/- 3%) report having been arrested for a crime but that only 13% (+/- 3%) have been convicted of a crime. Dr. Dowling is interviewed by a journalist about the findings of her study. The journalist criticizes the sample size as being too small and says that, because of that, the findings do not really have any real-world meaning. How should Dr. Dowling respond?

Another term for probability sampling is:

Why are techniques like cluster sampling and multistage sampling just as externally valid as simple random sampling?

Which of the following statements is true of random assignment and random sampling?

The difference between a cluster sample and a multistage sample is:

Dr. Cyril conducts a simple random sample of 500 men who became fathers for the first time in the past year. He finds that 23% of them report being unsure of their ability to be good fathers, plus or minus 4%. What is another term for the 4% value?

Why is the use of representative samples especially important in frequency claims?

When you are interrogating the external validity of a sample, which is the most important question to ask?

Why might a researcher choose purposive sampling over systematic sampling?

Why do studies that use probability samples have excellent external validity?

Explain why bigger samples are not always better samples.

If a study uses an unrepresentative sample, which of the following questions should you ask when assessing its external validity?