PSY 215 Chapter 7

Which of the following samples would be representative of the population of American teenagers? - a cluster sample of 1,000 teenagers from around the United States - a snowball sample of 1,500 teenagers from around the United States - an oversample of 1,250 U.S. teenagers - a purposive sample of 4,000 U.S. teenagers - a quota sample of 1,250 U.S. teenagers

- a cluster sample of 1,000 teenagers from around the United States - an oversample of 1,250 U.S. teenagers

If a study's sample is not generalizable to the rest of the population, we would say that the study has ___________ validity that is ___________.

- external - poor

sample can be biased in what 2 ways?

- might study only those they can contact conveniently - only those who volunteer to respond

Select all of the sampling techniques that use meaningful categories from the population (e.g., demographics) and involve recruiting a certain number of participants from each of the categories in the population.

- oversampling - stratified random sampling - quota sampling

A(n) _________ is the entire group of people that a researcher is interested in, while a(n) _________ is the smaller subset of that entire group that researchers study.A(n) ________ is conducted when a researcher investigates the entire group of people they are interested in.

- population - sample - census

Heejin wants to study the coping strategies used by partners of patients with breast cancer. She recruits participants by posting flyers about her study in the waiting rooms of several cancer treatment centers. Since she does not have enough participants, she then asks her participants to tell other partners of breast cancer patients about her study. Which of the following sampling methods does Heejin use in her study? - convenience sampling - purposive sampling - systematic sampling - snowball sampling

- purposive sampling - snowball sampling

Which of the following approaches increase external validity in a study? - using random assignment - using a representative sample - increasing the sample size - using a probability sampling technique

- using a probability sampling technique - using a representative sample

identify the samples as either biased or unbiased Ami randomly selects phone numbers for a telephone survey and then asks the people she calls to recruit additional participants

biased

identify the samples as either biased or unbiased Dr. Lin recruits participants from her psychology class and then randomly assigns them to one of three conditions.

biased

identify the samples as either biased or unbiased Zeynep posts advertisements for a study and then recruits every sixth person who contacts her.

biased

is this biased or unbiased? convenience sampling

biased

is this biased or unbiased? purposive sampling

biased

is this biased or unbiased? snowball sampling

biased

some members of the population of interest have a much higher probability than other members of being included in the sample

biased sample (unrepresentative)

a set of observations that contains all members of the population of interest.

census

Fill in the blanks to identify the type of sampling used in each scenario. Scenario 1: A researcher at a nearby university wants to look at what teachers in a certain school district think about new policy changes. The researcher makes a list of all the schools in the district and uses a random number generator to select five schools from the district. Then the researcher interviews every teacher at each of those five schools. The researcher is using __________ __________ in this study.

cluster sampling

Karim is investigating the well-being of health care workers in his county during the COVID-19 pandemic. He notes that the health care workers in his county consist of 15% physicians, 50% nurses, and 35% administrative staff. He is considering several different sampling techniques for his study. Match each term to the sampling technique that Karim is considering. Karim could randomly select 5 hospitals from his country and recruit all of the health care workers from those 5 hospitals

cluster sampling

clusters of participants within the population of interest are selected at random, followed by data collection from all individuals in each cluster

cluster sampling

what type of sampling is this? Researchers select five hospitals at random and survey all the nurses in each hospital.

cluster sampling

Jalon conducts a study to investigate whether anonymity affects the reported political opinions of college students. He recruits 156 participants from psychology classes and divides them into two groups. He asks the first group for their opinions about political issues and tells them that their responses will be completely anonymous. He asks the second group for their political opinions but does not tell them whether or not their opinions will be kept anonymous. Label the components of Jalon's study. Not all items will have a match. population-

college students

Jalon conducts a study to investigate whether anonymity affects the reported political opinions of college students. He recruits 156 participants from psychology classes and divides them into two groups. He asks the first group for their opinions about political issues and tells them that their responses will be completely anonymous. He asks the second group for their political opinions but does not tell them whether or not their opinions will be kept anonymous. Label the components of Jalon's study. Not all items will have a match. sampling method-

convenience sampling

using a sample of people who are easy to contact and readily available to participate

convenience sampling

what type of sampling is this? Dr. Khan asks his intro psych students to fill out a survey on sleep quality and stress after class.

convenience sampling

Dr. Lawrence is the director of Counseling Services at her university. She is planning to conduct a survey of 100 students to see how aware they are of the counseling services that the university offers. She wants the proportion of men and women in her sample to reflect the proportion at the university as a whole (55% women and 45% men). Dr. Lawrence plans to stand in the student center and ask people to participate until she has given the survey to 55 women and 45 men. Identify the true and false statements about Dr. Lawrence's study. Dr. Lawrence is using a representative sample

false

Dr. Lawrence is the director of Counseling Services at her university. She is planning to conduct a survey of 100 students to see how aware they are of the counseling services that the university offers. She wants the proportion of men and women in her sample to reflect the proportion at the university as a whole (55% women and 45% men). Dr. Lawrence plans to stand in the student center and ask people to participate until she has given the survey to 55 women and 45 men. Identify the true and false statements about Dr. Lawrence's study. Dr. Lawrence is using stratified random sampling

false

Identify the true and false statements about Internet-based samples. internet- based survey samples are always biased through self- selection

false

Identify the true and false statements about Internet-based samples. samples of people who have rated a specific product online are generally representative of the whole population of people who purchased the product

false

Identify the true and false statements about generalizability and external validity. External validity is always the highest priority in every type of claim.

false

Identify the true and false statements about generalizability and external validity. a large sample is always more representative than a small sample

false

Identify the true and false statements about generalizability and external validity. if a finding does not generalize to other populations, it is invalid

false

Identify the true and false statements about selecting research participants. combining sampling techniques increases bias

false

Identify the true and false statements about selecting research participants. self- selection is a form of unbiased sampling

false

Thora is considering whether the reports from a sample of drivers who have reported accidents on a navigation app are accurate. Identify the true and false statements about this sample of drivers. this group of drivers is a representative sample

false

Thora is considering whether the reports from a sample of drivers who have reported accidents on a navigation app are accurate. Identify the true and false statements about this sample of drivers. this sample consists of drivers who likely have the same personality traits as other drivers who have not reported accidents on the app

false

Fill in the blanks to identify the type of sampling used in each scenario. Scenario 2: The campus safety committee has asked Professor Ibrahim to study bicycling on his campus. He trains two observers to rate the safety behaviors of cyclists at various locations around campus. He randomly selects 10 observation locations from the places where bicycles can be ridden on campus and randomly selects five 1-hour durations for each location. He has his observers make observations at each of the 10 places for each of the five durations. Dr. Ibrahim is using _________________ .

multistage sampling

Karim is investigating the well-being of health care workers in his county during the COVID-19 pandemic. He notes that the health care workers in his county consist of 15% physicians, 50% nurses, and 35% administrative staff. He is considering several different sampling techniques for his study. Match each term to the sampling technique that Karim is considering. Karim could randomly select 5 hospitals from his county and then randomly select 50 health care workers from each of the selected hospitals

multistage sampling

two random samples are selected: a random sample of clusters and then a random sample of people within those clusters

multistage sampling

what type of sampling is this? Researchers select children at three different elementary schools at random by birth date.

multistage sampling

techniques involve nonrandom sampling and result in a biased sample

non probability sampling

Karim is investigating the well-being of health care workers in his county during the COVID-19 pandemic. He notes that the health care workers in his county consist of 15% physicians, 50% nurses, and 35% administrative staff. He is considering several different sampling techniques for his study. Match each term to the sampling technique that Karim is considering. Karim is concerned that 15 physicians might not give him a precise statistical estimate, so he could recruit more physicians and then adjust the results later

oversampling

in which the researcher intentionally overrepresents one or more groups

oversampling

what type of sampling is this? A survey interested in comparing prisoners to non-prisoners includes prisoners as 10% of its sample, even though they only make up 2.5% of the total population.

oversampling

the entire set of people or products in which you are interested

population

specifying a population to which researchers want to generalize

population of interest

Jalon conducts a study to investigate whether anonymity affects the reported political opinions of college students. He recruits 156 participants from psychology classes and divides them into two groups. He asks the first group for their opinions about political issues and tells them that their responses will be completely anonymous. He asks the second group for their political opinions but does not tell them whether or not their opinions will be kept anonymous. Label the components of Jalon's study. Not all items will have a match. sample-

psychology students

a biased sampling technique in which only certain kinds of people are included in a sample

purposive sampling

Karim is investigating the well-being of health care workers in his county during the COVID-19 pandemic. He notes that the health care workers in his county consist of 15% physicians, 50% nurses, and 35% administrative staff. He is considering several different sampling techniques for his study. Match each term to the sampling technique that Karim is considering. Karim could visit a local hospital and pass out his survey to health care workers that walk by until he reaches his goal of 15 physicians, 50 nurses, and 35 administrative staff

quota sampling

the researcher identifies subsets of the population of interest, sets a target number for each category in the sample, and nonrandomly selects individuals within each category until the quotas are filled

quota sampling

what type of sampling is this? Researchers conducting an online survey collect 50 men and 50 women in order to have equal gender representation.

quota sampling

creating a sample using some random method so each member of the population of interest has an equal chance of being selected

random sampling

every member of the population of interest has an equal and known chance of being selected for the sample, regardless of whether they are convenient or motivated to volunteer

random sampling (probability sample)

a smaller set, taken from that population

sample

a term used when a sample is known to contain only people who volunteer to participate

self selection

the most basic form of probability sampling, in which the sample is chosen completely at random from the population of interest

simple random sampling

what type of sampling is this? Researchers choose students at random by selecting the last digit of their student IDs.

simple random sampling

a variation on purposive sampling, a biased sampling technique in which participants are asked to recommend acquaintances for the study

snowball sampling

what type of sampling is this? At the end of an online survey, participants are asked to tell their friends about it.

snowball sampling

Karim is investigating the well-being of health care workers in his county during the COVID-19 pandemic. He notes that the health care workers in his county consist of 15% physicians, 50% nurses, and 35% administrative staff. He is considering several different sampling techniques for his study. Match each term to the sampling technique that Karim is considering. Karim could randomly select 15 physicians, 50 nurses, and 35 administrative staff for his sample of 100 participants

stratified random sampling

Scenario 1: A college administrator knows that 30% of the students at her college are from out of state, and she wants to make sure that she maintains this proportion in her survey about admission practices at the college. She has a list of all the out-of-state and in-state students and randomly selects 30 students from the out-of-state list and 70 students from the in-state list. She is using _______________.

stratified random sampling

in which the researcher purposefully selects particular demographic categories, or strata, and then randomly selects individuals within each of the categories, proportionate to their assumed membership in the population

stratified random sampling

Scenario 2: The directors of an annual community concert want to learn the musical preferences of the audience. The directors choose 2 and 6 from a random number generator and place a survey card on every sixth seat beginning with the second seat. All the cards are returned as the audience leaves. They are using _____________.

systematic sampling

a probability sampling technique in which the researcher uses a randomly chosen number N, and counts off every Nth member of a population to achieve a sample

systematic sampling

what type of sampling is this? A researcher approaches every fifth shopper who walks into a grocery store.

systematic sampling

Dr. Lawrence is the director of Counseling Services at her university. She is planning to conduct a survey of 100 students to see how aware they are of the counseling services that the university offers. She wants the proportion of men and women in her sample to reflect the proportion at the university as a whole (55% women and 45% men). Dr. Lawrence plans to stand in the student center and ask people to participate until she has given the survey to 55 women and 45 men. Identify the true and false statements about Dr. Lawrence's study. Dr. Lawrence is using quota sampling

true

Dr. Lawrence is the director of Counseling Services at her university. She is planning to conduct a survey of 100 students to see how aware they are of the counseling services that the university offers. She wants the proportion of men and women in her sample to reflect the proportion at the university as a whole (55% women and 45% men). Dr. Lawrence plans to stand in the student center and ask people to participate until she has given the survey to 55 women and 45 men. Identify the true and false statements about Dr. Lawrence's study. Dr. Lawrence's study will have poor external validity

true

Identify the true and false statements about Internet-based samples. internet- based samples might consist of people who have stronger opinions than those who do not post their opinions online

true

Identify the true and false statements about Internet-based samples. the external validity of an internet- based survey depends on how the sample is recruited

true

Identify the true and false statements about generalizability and external validity. A random sample of 1,000 people is enough to generalize to a population of 100 million people.

true

Identify the true and false statements about selecting research participants. convenience sampling is the most commonly used sampling technique

true

Identify the true and false statements about selecting research participants. random assignment is only used in experimental designs

true

Thora is considering whether the reports from a sample of drivers who have reported accidents on a navigation app are accurate. Identify the true and false statements about this sample of drivers. in this case, the sampling method does not affect the accuracy of the report

true

Thora is considering whether the reports from a sample of drivers who have reported accidents on a navigation app are accurate. Identify the true and false statements about this sample of drivers. the sample was obtained through self- selection

true

identify the samples as either biased or unbiased Nasir selects telephone numbers from a random-digit dialer and then asks for the youngest male in the house who is at least 18.

unbiased

identify the samples as either biased or unbiased Travis randomly selects 15 major universities and then randomly selects 15 students from each of those universities.

unbiased

is this biased or unbiased? probability sampling

unbiased

is this biased or unbiased? stratified random sampling

unbiased

is this biased or unbiased? systematic sampling

unbiased

all members of the population have an equal chance of being included in the sample

unbiased sample (representative)

If they determine that the final sample contains fewer members of a subgroup than it should (such as fewer young adults or fewer low- income people), they adjust the data so responses from members of underrepresented categories count more and overrepresented members count less

weighting