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
