Quiz 7- Chapter 7

Which of the following is true of probability sampling? a) It is the best way to obtain a representative sample. b) It is the same as random assignment. c) It results in larger samples than nonprobability sampling. d) It should be used when external validity is not the goal of the study.

a) It is the best way to obtain a representative sample.

Which of the following statements is true of random assignment and random sampling? a) Random assignment is necessary for internal validity, whereas random assignment is necessary for external validity. b) They both are necessary for frequency claims. c) They both mean the same thing. d) Random sampling is more important than random assignment.

a) Random assignment is necessary for internal validity, whereas random assignment is necessary for external validity.

Convenience sampling relies on which of the following? a) Studying people who are easy to find b) Studying people who are willing to participate c) Studying people who are typical d) Studying people who are colleagues of the researcher

a) Studying people who are easy to find

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? a) This will lead to a biased sample because the type of students who take Psychology and Law may be different from the type of students who take Introduction to Neuroscience. b) This will lead to a biased sample because of self-selection. c) This will lead to a biased sample because the Psychology and Law students have a lot of time to complete the survey. d) The will lead to a sample that is representative of both of his classes.

a) This will lead to a biased sample because the type of students who take Psychology and Law may be different from the type of students who take Introduction to Neuroscience.

A sample is always ________ a population. a) More expensive to measure than b) Smaller than c) More interesting than d) More scientific than

b) Smaller than

Dr. Torres 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? a) Purposive sampling b) Snowball sampling c) Convenience sampling d) Self-selection sampling

b) Snowball sampling

Which of the following is true regarding interrogating frequency claims? a) Their accuracy can usually be determined. b)The chief concern is to evaluate the sampling technique. c) The most important thing to consider is the size of the sample. d) Frequency claims cannot be interrogated.

b)The chief concern is to evaluate the sampling technique.

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, what is Dr. Kramer's likely population of interest? a) All students at the university b) All psychology majors c) All students he is currently teaching d) All students in his Psychology and Law course

c) All students he is currently teaching

The difference between a cluster sample and a stratified random sample is: a) Cluster samples study all possible clusters; stratified random samples randomly select strata b) Cluster samples use oversampling; stratified random samples use undersampling c) Cluster samples use randomly selected clusters; stratified random samples use pre-determined strata d) There is no difference between them

c) Cluster samples use randomly selected clusters; stratified random samples use pre-determined strata

Why do studies that use probability samples have excellent external validity? a) They have good internal validity too. b) They study every member of the population of interest. c) They are more complicated to do. d) All members of the population are equally likely to be represented in the sample.

d) All members of the population are equally likely to be represented in the sample.