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

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 asks Dr.Dowling how many people live in all five,hospitals and Dr.Dowling answers.The journalist replies that given that there are only about 4,000 people,it seems reasonable that Dr.Dowling should have studied the entire population rather than just drawing a sample for her study to really tell us something about people suffering from mental illness.How should Dr.Dowling respond?

A representative sample is most necessary for which type of claim (frequency,association,or causal)? Why?

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. -In the above scenario,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?

Explain why a researcher may wish to choose snowballing sampling over a representative sampling technique.

Which of the following is true regarding interrogating frequency claims?

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.

Which of the following is NOT an example of a probability sample?

Explain why bigger samples are not always better samples.

Dr.Jackson is a personality psychologist who is interested in studying the characteristics of people who report being abducted by UFOs.She finds several people in a support group to research and asks them if they can provide the names and contact information of other people who have also been abducted.Upon contacting these new participants,she asks them to refer her to even more people they may know who have been abducted.This is an example of what kind of sampling?

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

Another term for probability sampling is:

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. -Choose a representative sampling technique and a biased sampling technique.Explain how Dr.Dowling would implement each of these sampling techniques.

Explain the two reasons nonrandom samples are sometimes acceptable.

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

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 because of that,the findings do not really have any real world meaning.How should Dr.Dowling respond?

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

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. -In the above scenario,if all the students in Dr.Kramer's two classes complete the survey,then Dr.Kramer has done which of the following?

If researchers measure every member of a population,they have:

For his research methods class project,Hiro is studying the effect of pet ownership on stress levels.Although a lot of research has been done on dog and cat owners,not much is known about other pets so Hiro decides to study hamster owners.Which of the following would demonstrate a snowball sampling technique?

External validity is most important for which of the following claims?