Ch. 7 – PSY 350

population
The entire set of people or products in which one is interested

Sample
A smaller set, taken from part of a population

census
When every single member of a population is tested/studied

population of interest
When researchers generalize a limited population to study

Dr. Jennings is doing a study on the experience of being a racial minority on a college campus. He goes to the Asian Student Association, Black Student Union, and Hispanic Student Group on his campus to recruit participants for his study. Dr. Jennings only includes Asians, African-Americans, and Hispanic participants in his study. What type of sampling is Dr. Jennings using?
Question 2 options:

quota sampling

cluster sampling

systematic sampling

purposive sampling

purposive sampling

Biased sample
unrepresentative sample – some members of the population of interest have a much higher probability of being included in the sample compared to other members

representative sample/unbiased sample
all members of the population have an equal chance of being included in the sample. Only representative samples allow us to make inferences about the population of interest.

convenience sampling
Using a sample of people who are readily available to participate.
EX: College professors using college students

Quota sampling
A biased sampling technique in which a researcher identifies subsets of the population of interest, sets a target number for each category in the sample, and non-randomly selects individuals within each category until the quotas are filled.
In quota sampling participants are selected non-randomly (through convenience or purposive sampling).

systematic sampling
A probability sampling technique in which the researcher counts off members of a population to achieve a sample, using a randomly chosen interval (every nth person, where n is a randomly selected number)

Purposive sampling
A biased sampling technique in which only certain kinds of people are included in a sampling. Only purposive when this is not a random sample.

Cluster sampling
A probability sampling technique in which clusters of participants within the population of interest are selected at random, followed by data collection from all individuals in each cluster.

self – selection
a term used when a sample is known to contain only people who volunteer to participate.
EX: online polling – can have bad external validity.
ex: parents asked ‘ was your child an early reader? ‘ a higher than reality percentage showed because parents who did have early readers were eager to answer this polling question. not representative.
A more realistic ex would be people who rate items or amazon, or books on goodreads

probability sampling/random sampling
every member of the population of interest has an equal chance of being selected for the sample, regardless of whether they are close by, easy to contact, or motivated to respond

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

What kind of sample is best for external validity?
Question 3 options:

a sample that can be collected as quickly as possible

a sample where each member of the population has an equal chance of being selected

a sample that includes the majority of the population

the largest sample possible

‘In most cases, researchers are not able to check accuracy of their samples’ estimates, because they hardly ever complete a full census of a population on the variable of interest.’
In research, is a bigger sample always a better sample? not necessarily.
A sample of 1,000 people, as long as it is random, allows them to generalize to the population quite accurately.

Which of the following is considered a representative sampling method?
Question 4 options:

snowball sampling

convenience sampling

self-selected sampling

systematic sampling

systematic sampling

Snowball sampling
a variation of purposive sampling that can help researchers find rare individuals, in which participants are asked to recommend a few acquaintances for the study.
Nonrepresentative

Which of the following is most important for enhancing external validity?
Question 5 options:

random sampling

random assignment

a large sample size

using measures that are valid and reliable

random sampling

Multistage Sampling
Two random samples are selected: a random sample of clusters, then a random sample of people within those clusters.

Stratified Random Sampling
A multistage technique in which the researcher selects particular demographic categories on purpose and then randomly selects individuals within each of the categories.

Dr. Jennings is doing a study on the experience of being a racial minority on a college campus. He goes to the Asian Student Association, Black Student Union, and Hispanic Student Group n his campus to recruit participants for his study. Dr. Jennings only includes Asians, African-Americans, and Hispanic participants in his study. What type of sampling is Dr. Jennings using?
Purposive Sampling

Beth is working on a research study focused on attention span in children. Among the participants, the group of 11-year old boys is underrepresented. Beth asks her 11-year old brother to distribute flyers about participation in the study to his male classmates and soccer team. What type of sampling is this?
Snowball

Which of the following is considered a biased sampling method?
-Convenience Sampling
-Cluster Sampling
-Stratified Random Sampling
-Simple Random Sampling
Convenience Sampling

A political research center obtains a list of phone numbers of all registered voters in Texas and uses a random number generator to select 1,000 of the phone numbers to call. They ask each voter which gubernatorial candidate they plan to vote for in the upcoming election. What is the population of interest that the research center wants to generalize to?
All registered voters in Texas

Dr. Rhodes is interested in how differing levels of light affect how people perceive color. He finds participants for this research study by making an announcement in several psychology classes at his University. What kind of sampling is Dr. Rhodes using?
Convenience Sampling

The superintendent of schools in a small town in Ohio made a lot of policy changes to the way school administrators worked in his district. A researcher at a nearby university wanted to look at what teachers in his district thought about the changes. The researcher made a list of all of the schools in the district and used a random number generator to select a sample of five schools from the district. Then the researcher interviewed each teach at each of those 5 schools. What sampling method did the researcher use?
Cluster sampling

A _____ is the entire set of people in which researchers are interested
Population

Mr. Stratford is the president of a national organization of lesbian, bisexual, gay, and transgender people in the United States. He wants to survey 1,000 members of his organization about the position they want the organization not to take on several political issues. He knows that transgender people make up only 5% of his organization. But he wants to make sure that their views are accurately represented. He decides that he will randomly sample 100 transgender members and then adjust the final results so that transgender people are weighted to their actual proportion in the organization. What type of sampling is Mr. Stratford using?
Oversampling

Which sample would be most likely to represent the population of American teenagers?
A cluster sampling of 1,000 teenagers from around the United States

Which of the following is most important for enhancing external validity?
Random sampling

What kind of sample is best for external validity?
A sample where each member of the population has an equal chance of being selected

A college administrator knows that 70% of the students at his college are from out of state, so he decides to make sure that he includes 70 out of state students and 30 in state students in his survey about admission practices at the college. He randomly selects 70 students from the out of state list and 30 students from the in state list. What sampling method is he using?
Stratified random sampling

_____ is when you study every member of a population
Census

A political research center obtains a list of phone numbers for all registered voters in Texas and uses a random number generator to select 1,000 of the phone number to call. They ask each voter which gubernatorial candidate they plan to vote for in the upcoming election. What sampling method is being used?
Simple random sampling

Which of the following is considered a representative sampling method?
Systematic Sampling

The campus safety committee has asked Professor Ibrahim to study bicycling on his campus. He trains two observers and has them observe the number of cyclists and their safety at various points around campus. He selects 10 observation locations at random from the places bicycles can be ridden on campus and five one-hour spans of time at random from daylight hours at each place. He had his observers make observations at each of the ten places for each of the five time spans. What type of sampling is he using?
Multistage sampling

The directors of an annual community concert want to find the musical preferences of the audience. The ushers place a survey card on every sixth seat beginning with the second seat (2 and 6 were chosen form a random number table). All of the cards are returned as the audience leaves. Which type of sampling is being used?
Systematic Sampling

Dr. Lawrence is the director of Counseling Services at her university. She is planning to conduct a survey of 100 students at the university to see how aware they are of the counseling services that are offered at the university. She wants the proportion of males and females in her sample to reflect the proportion in the university as a whole. Dr. Lawrence plants to stand in the Student Union and ask people to participate until she has given the survey to 55 females and 45 males. What type of sampling method is Dr. Lawrence going to use?
Quota Sampling

Mr. Stratford is the president of a national organization of lesbian, bisexual, gay, and transgender people in the United States. He wants to survey 1,000 members of his organization, but he wants to make sure that their views are accurately represented. He decides that he will randomly sample 100 transgender members and teh nadjust the final results so that transgender people are weighted to their actual proportion in the organization. Is Mr. Stratford collecting a representative sample?
Yes, because the transgender people in the final sample were sampled randomly from the population of transgender people in the organization

A sample is always ____ a population
smaller than

What sample size is often cited as the optimal balance between accuracy and effort?
1,000

The student government at a college is interested in determining how important intercollegiate sports are to the students there. Since all students have e-mail accounts, they are able to send a survey to all the students. About 50% of the students respond. Which is the most likely bias in this sample?
Self-selection bias

What kind of sample is best for external validity?
A sample where each member of the population has an equal chance of being selected

Dr. Rhodes is interested in how differing levels of light affect how people perceive color. He finds participants for this research study by making an announcement in several psychology classes at his university. Should Dr. Rhodes be concerned about using this sampling method?
No, because external validity probably doesn’t matter for the type of claim he is making

Dr. Lawrence is the director of Counseling services at her university. She is planning to conduct a survey of 100 students at the university to see how aware they are of the counseling services that are offered at the university. She wants to proportion of males and females in her sample to reflect the proportion in the university as a whole. Dr. Lawrence plants to stand in the student union and ask people to participate until she has given the survey to 55 females and 45 males. Is Dr. Lawrence collecting a representative sample?
No, because the participants are selected non-randomly

What kind of sample is best for external validity?
a sample where each member of the population has an equal chance of being selected

A sample is always __________ a population.
smaller than

________ is when you study every member of a population.
A census

A college administrator knows that 70 percent of the students at his college are from out of state, so he decides to make sure that he includes 70 out-of-state students and 30 in-state students in his survey about admission practices at the college. He has a list of all of the out-of-state and all of the in-state students currently enrolled at the college. He randomly selects 70 students from the out-of-state list and 30 students from the in-state list. What sampling method is he using?
stratified random sampling

The student government at a college is interested in determining how important intercollegiate sports are to the students there. Since all students have e-mail accounts, they are able to send a survey to all the students. About 50 percent of the students respond. What is the most likely bias in this sample?
self-selection bias

What is considered a representative sampling method?
systematic sampling

What is considered a biased sampling method?
convenience sampling

Dr. Jennings is doing a study on the experience of being a racial minority on a college campus. He goes to the Asian Student Association, Black Student Union, and Hispanic Student Group on his campus to recruit participants for his study. Dr. Jennings only includes Asians, African-Americans, and Hispanic participants in his study. What type of sampling is Dr. Jennings using?
purposive sampling

A political research center obtains a list of phone numbers for all registered voters in Texas and uses a random number generator to select 1,000 of the phone numbers to call. They ask each voter which gubernatorial candidate they plan to vote for in the upcoming election. What is the population of interest that the research center wants to generalize to?
all registered voters in Texas

Which sample would be most likely to represent the population of American teenagers?
a cluster sampling of 1,000 teenagers from around the United States

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

Dr. Oishi is an educational psychologist interested in students’ attitudes toward math and the effect of those attitudes on performance on standardized tests. He chooses his local school district to study. There are 15 middle schools, and he randomly chooses five. Then, of the 1,500 students in each of those five schools, he randomly recruits 250 students. This is an example of what sampling techniques?
Multistage sample

Online surveys commonly suffer from what?
Self-selection

Another term for probability sampling is:
Random sampling

Why are techniques like cluster sampling and multistage sampling just as externally valid as simple random sampling?
They all contain elements of random selection.

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?
Snowball sampling

What does NOT result in a biased sample?
Systematic sample

What statement is true of random assignment and random sampling?
Random assignment is necessary for internal validity, whereas random sampling is necessary for external validity.

What kind of sample is best for external validity?
a sample where each member of the population has an equal chance of being selected

Dr. Rhodes is interested in how differing levels of light affect how people perceive color. He finds participants for this research study by making an announcement in several psychology classes at his university. What kind of sampling method is Dr. Rhodes using?
convenience sampling

Dr. Rhodes is interested in how differing levels of light affect how people perceive color. He finds participants for this research study by making an announcement in several psychology classes at his university. Should Dr. Rhodes be concerned about using this sampling method?
No, because external validity probably doesn’t matter for the type of claim he is making.

A sample is always __________ a population.
smaller than

________ is when you study every member of a population.
A census

A ________ is the entire set of people in which the researchers are interested.
population

The superintendent of schools in a small town in Ohio made a lot of policy changes to the way school administration worked in his district. A researcher at a nearby university wanted to look at what teachers in his district thought about the changes. The researcher made a list of all of the schools in the district and used a random number generator to select a sample of five schools from the district. Then the researcher interviewed every teacher at each of those five schools. What sampling method did the researcher use?
cluster sampling

A college administrator knows that 70 percent of the students at his college are from out of state, so he decides to make sure that he includes 70 out-of-state students and 30 in-state students in his survey about admission practices at the college. He has a list of all of the out-of-state and all of the in-state students currently enrolled at the college. He randomly selects 70 students from the out-of-state list and 30 students from the in-state list. What sampling method is he using?
stratified random sampling

The student government at a college is interested in determining how important intercollegiate sports are to the students there. Since all students have e-mail accounts, they are able to send a survey to all the students. About 50 percent of the students respond. Which is the most likely bias in this sample?
self-selection bias

The directors of an annual community concert want to find the musical preferences of the audience. The ushers place a survey card on every sixth seat beginning with the second seat (2 and 6 were chosen from a random number table). All of the cards are returned as the audience leaves. Which type of sampling is being used?
systematic sampling

Which of the following is most important for enhancing external validity?
random sampling

Which of the following is considered a representative sampling method?
systematic sampling

Which of the following is considered a biased sampling method?
convenience sampling

Beth is working on a research study focused on attention span in children. Among the participants, the group of 11-year-old boys is underrepresented. Beth asks her 11-year-old brother to distribute flyers about participation in the study to his male classmates and soccer team. What type of sampling is this?
snowball

Typically, in which type of claim is it most important to have a random sample?
frequency

What sample size is often cited as the optimal balance between accuracy and effort?
1,000

Mr. Stratford is the president of a national organization of lesbian, bisexual, gay, and transgender people in the United States. He wants to survey 1,000 members of his organization about the position they want the organization to take on several political issues. He knows that transgender people make up only 5 percent of his organization, but he wants to make sure that their views are accurately represented. He decides that he will randomly sample 100 transgender members and then adjust the final results so that transgender people are weighted to their actual proportion in the organization. What type of sampling is Mr. Stratford using?
oversampling

Mr. Stratford is the president of a national organization of lesbian, bisexual, gay, and transgender people in the United States. He wants to survey 1,000 members of his organization about the position they want the organization to take on several political issues. He knows that transgender people make up only 5 percent of his organization, but he wants to make sure that their views are accurately represented. He decides that he will randomly sample 100 transgender members and then adjust the final results so that transgender people are weighted to their actual proportion in the organization. Is Mr. Stratford collecting a representative sample?
Yes, because the transgender people in the final sample were sampled randomly from the population of transgender people in the organization.

Dr. Jennings is doing a study on the experience of being a racial minority on a college campus. He goes to the Asian Student Association, Black Student Union, and Hispanic Student Group on his campus to recruit participants for his study. Dr. Jennings only includes Asians, African-Americans, and Hispanic participants in his study. What type of sampling is Dr. Jennings using?
purposive sampling

Dr. Lawrence is the director of Counseling Services at her university. She is planning to conduct a survey of 100 students at the university to see how aware they are of the counseling services that are offered at the university. She wants the proportion of males and females in her sample to reflect the proportion in the university as a whole (55 percent female and 45 percent male). Dr. Lawrence plans to stand in the Student Union and ask people to participate until she has given the survey to 55 females and 45 males. What type of sampling method is Dr. Lawrence going to use?
quota sampling

Dr. Lawrence is the director of Counseling Services at her university. She is planning to conduct a survey of 100 students at the university to see how aware they are of the counseling services that are offered at the university. She wants the proportion of males and females in her sample to reflect the proportion in the university as a whole (55 percent female and 45 percent male). Dr. Lawrence plans to stand in the Student Union and ask people to participate until she has given the survey to 55 females and 45 males. Is Dr. Lawrence collecting a representative sample?
No, because the participants are selected nonrandomly.

A political research center obtains a list of phone numbers for all registered voters in Texas and uses a random number generator to select 1,000 of the phone numbers to call. They ask each voter which gubernatorial candidate they plan to vote for in the upcoming election. What is the population of interest that the research center wants to generalize to?
all registered voters in Texas

The campus safety committee has asked Professor Ibrahim to study bicycling on his campus. He trains two observers and has them observe the number of cyclists and their safety at various points around campus. He selects ten observation locations at random from the places bicycles can be ridden on campus and five one-hour spans of time at random from the daylight hours for each place. He has his observers make observations at each of the ten places for each of the five time spans. What type of sampling is he using?
multistage sampling

A political research center obtains a list of phone numbers for all registered voters in Texas and uses a random number generator to select 1,000 of the phone numbers to call. They ask each voter which gubernatorial candidate they plan to vote for in the upcoming election. What sampling method is being used?
simple random sampling

Which sample would be most likely to represent the population of American teenagers?
a cluster sampling of 1,000 teenagers from around the United States

What kind of sample is best for external validity?
a sample where each member of the population has an equal chance of being selected

Dr. Rhodes is interested in how differing levels of light affect how people perceive color. He finds participants for this research study by making an announcement in several psychology classes at his university. What kind of sampling method is Dr. Rhodes using?
convenience sampling

Dr. Rhodes is interested in how differing levels of light affect how people perceive color. He finds participants for this research study by making an announcement in several psychology classes at his university. Should Dr. Rhodes be concerned about using this sampling method?
No, because external validity probably doesn’t matter for the type of claim he is making.

A sample is always __________ a population.
smaller than

________ is when you study every member of a population.
A census

A ________ is the entire set of people in which the researchers are interested.
population

The superintendent of schools in a small town in Ohio made a lot of policy changes to the way school administration worked in his district. A researcher at a nearby university wanted to look at what teachers in his district thought about the changes. The researcher made a list of all of the schools in the district and used a random number generator to select a sample of five schools from the district. Then the researcher interviewed every teacher at each of those five schools. What sampling method did the researcher use?
cluster sampling

A college administrator knows that 70 percent of the students at his college are from out of state, so he decides to make sure that he includes 70 out-of-state students and 30 in-state students in his survey about admission practices at the college. He has a list of all of the out-of-state and all of the in-state students currently enrolled at the college. He randomly selects 70 students from the out-of-state list and 30 students from the in-state list. What sampling method is he using?
stratified random sampling

The student government at a college is interested in determining how important intercollegiate sports are to the students there. Since all students have e-mail accounts, they are able to send a survey to all the students. About 50 percent of the students respond. Which is the most likely bias in this sample?
self-selection bias

The directors of an annual community concert want to find the musical preferences of the audience. The ushers place a survey card on every sixth seat beginning with the second seat (2 and 6 were chosen from a random number table). All of the cards are returned as the audience leaves. Which type of sampling is being used?
systematic sampling

Which of the following is most important for enhancing external validity?
random sampling

Which of the following is considered a representative sampling method?
systematic sampling

Which of the following is considered a biased sampling method?
convenience sampling

Beth is working on a research study focused on attention span in children. Among the participants, the group of 11-year-old boys is underrepresented. Beth asks her 11-year-old brother to distribute flyers about participation in the study to his male classmates and soccer team. What type of sampling is this?
snowball

Typically, in which type of claim is it most important to have a random sample?
frequency

What sample size is often cited as the optimal balance between accuracy and effort?
1,000

Mr. Stratford is the president of a national organization of lesbian, bisexual, gay, and transgender people in the United States. He wants to survey 1,000 members of his organization about the position they want the organization to take on several political issues. He knows that transgender people make up only 5 percent of his organization, but he wants to make sure that their views are accurately represented. He decides that he will randomly sample 100 transgender members and then adjust the final results so that transgender people are weighted to their actual proportion in the organization. What type of sampling is Mr. Stratford using?
oversampling

Mr. Stratford is the president of a national organization of lesbian, bisexual, gay, and transgender people in the United States. He wants to survey 1,000 members of his organization about the position they want the organization to take on several political issues. He knows that transgender people make up only 5 percent of his organization, but he wants to make sure that their views are accurately represented. He decides that he will randomly sample 100 transgender members and then adjust the final results so that transgender people are weighted to their actual proportion in the organization. Is Mr. Stratford collecting a representative sample?
Yes, because the transgender people in the final sample were sampled randomly from the population of transgender people in the organization.

Dr. Jennings is doing a study on the experience of being a racial minority on a college campus. He goes to the Asian Student Association, Black Student Union, and Hispanic Student Group on his campus to recruit participants for his study. Dr. Jennings only includes Asians, African-Americans, and Hispanic participants in his study. What type of sampling is Dr. Jennings using?
purposive sampling

Dr. Lawrence is the director of Counseling Services at her university. She is planning to conduct a survey of 100 students at the university to see how aware they are of the counseling services that are offered at the university. She wants the proportion of males and females in her sample to reflect the proportion in the university as a whole (55 percent female and 45 percent male). Dr. Lawrence plans to stand in the Student Union and ask people to participate until she has given the survey to 55 females and 45 males. What type of sampling method is Dr. Lawrence going to use?
quota sampling

Dr. Lawrence is the director of Counseling Services at her university. She is planning to conduct a survey of 100 students at the university to see how aware they are of the counseling services that are offered at the university. She wants the proportion of males and females in her sample to reflect the proportion in the university as a whole (55 percent female and 45 percent male). Dr. Lawrence plans to stand in the Student Union and ask people to participate until she has given the survey to 55 females and 45 males. Is Dr. Lawrence collecting a representative sample?
No, because the participants are selected nonrandomly.

A political research center obtains a list of phone numbers for all registered voters in Texas and uses a random number generator to select 1,000 of the phone numbers to call. They ask each voter which gubernatorial candidate they plan to vote for in the upcoming election. What is the population of interest that the research center wants to generalize to?
all registered voters in Texas

The campus safety committee has asked Professor Ibrahim to study bicycling on his campus. He trains two observers and has them observe the number of cyclists and their safety at various points around campus. He selects ten observation locations at random from the places bicycles can be ridden on campus and five one-hour spans of time at random from the daylight hours for each place. He has his observers make observations at each of the ten places for each of the five time spans. What type of sampling is he using?
multistage sampling

A political research center obtains a list of phone numbers for all registered voters in Texas and uses a random number generator to select 1,000 of the phone numbers to call. They ask each voter which gubernatorial candidate they plan to vote for in the upcoming election. What sampling method is being used?
simple random sampling

Which sample would be most likely to represent the population of American teenagers?
a cluster sampling of 1,000 teenagers from around the United States

population
The entire set of people or products in which one is interested

Sample
A smaller set, taken from part of a population

census
When every single member of a population is tested/studied

population of interest
When researchers generalize a limited population to study

Dr. Jennings is doing a study on the experience of being a racial minority on a college campus. He goes to the Asian Student Association, Black Student Union, and Hispanic Student Group on his campus to recruit participants for his study. Dr. Jennings only includes Asians, African-Americans, and Hispanic participants in his study. What type of sampling is Dr. Jennings using?
Question 2 options:

quota sampling

cluster sampling

systematic sampling

purposive sampling

purposive sampling

Biased sample
unrepresentative sample – some members of the population of interest have a much higher probability of being included in the sample compared to other members

representative sample/unbiased sample
all members of the population have an equal chance of being included in the sample. Only representative samples allow us to make inferences about the population of interest.

convenience sampling
Using a sample of people who are readily available to participate.
EX: College professors using college students

Quota sampling
A biased sampling technique in which a researcher identifies subsets of the population of interest, sets a target number for each category in the sample, and non-randomly selects individuals within each category until the quotas are filled.
In quota sampling participants are selected non-randomly (through convenience or purposive sampling).

systematic sampling
A probability sampling technique in which the researcher counts off members of a population to achieve a sample, using a randomly chosen interval (every nth person, where n is a randomly selected number)

Purposive sampling
A biased sampling technique in which only certain kinds of people are included in a sampling. Only purposive when this is not a random sample.

Cluster sampling
A probability sampling technique in which clusters of participants within the population of interest are selected at random, followed by data collection from all individuals in each cluster.

self – selection
a term used when a sample is known to contain only people who volunteer to participate.
EX: online polling – can have bad external validity.
ex: parents asked ‘ was your child an early reader? ‘ a higher than reality percentage showed because parents who did have early readers were eager to answer this polling question. not representative.
A more realistic ex would be people who rate items or amazon, or books on goodreads

probability sampling/random sampling
every member of the population of interest has an equal chance of being selected for the sample, regardless of whether they are close by, easy to contact, or motivated to respond

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

What kind of sample is best for external validity?
Question 3 options:

a sample that can be collected as quickly as possible

a sample where each member of the population has an equal chance of being selected

a sample that includes the majority of the population

the largest sample possible

‘In most cases, researchers are not able to check accuracy of their samples’ estimates, because they hardly ever complete a full census of a population on the variable of interest.’
In research, is a bigger sample always a better sample? not necessarily.
A sample of 1,000 people, as long as it is random, allows them to generalize to the population quite accurately.

Which of the following is considered a representative sampling method?
Question 4 options:

snowball sampling

convenience sampling

self-selected sampling

systematic sampling

systematic sampling

Snowball sampling
a variation of purposive sampling that can help researchers find rare individuals, in which participants are asked to recommend a few acquaintances for the study.
Nonrepresentative

Which of the following is most important for enhancing external validity?
Question 5 options:

random sampling

random assignment

a large sample size

using measures that are valid and reliable

random sampling

Multistage Sampling
Two random samples are selected: a random sample of clusters, then a random sample of people within those clusters.

Stratified Random Sampling
A multistage technique in which the researcher selects particular demographic categories on purpose and then randomly selects individuals within each of the categories.

What kind of sample is best for external validity?
a sample where each member of the population has an equal chance of being selected

A sample is always __________ a population.
smaller than

________ is when you study every member of a population.
A census

A college administrator knows that 70 percent of the students at his college are from out of state, so he decides to make sure that he includes 70 out-of-state students and 30 in-state students in his survey about admission practices at the college. He has a list of all of the out-of-state and all of the in-state students currently enrolled at the college. He randomly selects 70 students from the out-of-state list and 30 students from the in-state list. What sampling method is he using?
stratified random sampling

The student government at a college is interested in determining how important intercollegiate sports are to the students there. Since all students have e-mail accounts, they are able to send a survey to all the students. About 50 percent of the students respond. What is the most likely bias in this sample?
self-selection bias

What is considered a representative sampling method?
systematic sampling

What is considered a biased sampling method?
convenience sampling

Dr. Jennings is doing a study on the experience of being a racial minority on a college campus. He goes to the Asian Student Association, Black Student Union, and Hispanic Student Group on his campus to recruit participants for his study. Dr. Jennings only includes Asians, African-Americans, and Hispanic participants in his study. What type of sampling is Dr. Jennings using?
purposive sampling

A political research center obtains a list of phone numbers for all registered voters in Texas and uses a random number generator to select 1,000 of the phone numbers to call. They ask each voter which gubernatorial candidate they plan to vote for in the upcoming election. What is the population of interest that the research center wants to generalize to?
all registered voters in Texas

Which sample would be most likely to represent the population of American teenagers?
a cluster sampling of 1,000 teenagers from around the United States

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

Dr. Oishi is an educational psychologist interested in students’ attitudes toward math and the effect of those attitudes on performance on standardized tests. He chooses his local school district to study. There are 15 middle schools, and he randomly chooses five. Then, of the 1,500 students in each of those five schools, he randomly recruits 250 students. This is an example of what sampling techniques?
Multistage sample

Online surveys commonly suffer from what?
Self-selection

Another term for probability sampling is:
Random sampling

Why are techniques like cluster sampling and multistage sampling just as externally valid as simple random sampling?
They all contain elements of random selection.

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?
Snowball sampling

What does NOT result in a biased sample?
Systematic sample

What statement is true of random assignment and random sampling?
Random assignment is necessary for internal validity, whereas random sampling is necessary for external validity.

population
The entire set of people or products in which one is interested

Sample
A smaller set, taken from part of a population

census
When every single member of a population is tested/studied

population of interest
When researchers generalize a limited population to study

Dr. Jennings is doing a study on the experience of being a racial minority on a college campus. He goes to the Asian Student Association, Black Student Union, and Hispanic Student Group on his campus to recruit participants for his study. Dr. Jennings only includes Asians, African-Americans, and Hispanic participants in his study. What type of sampling is Dr. Jennings using?
Question 2 options:

quota sampling

cluster sampling

systematic sampling

purposive sampling

purposive sampling

Biased sample
unrepresentative sample – some members of the population of interest have a much higher probability of being included in the sample compared to other members

representative sample/unbiased sample
all members of the population have an equal chance of being included in the sample. Only representative samples allow us to make inferences about the population of interest.

convenience sampling
Using a sample of people who are readily available to participate.
EX: College professors using college students

Quota sampling
A biased sampling technique in which a researcher identifies subsets of the population of interest, sets a target number for each category in the sample, and non-randomly selects individuals within each category until the quotas are filled.
In quota sampling participants are selected non-randomly (through convenience or purposive sampling).

systematic sampling
A probability sampling technique in which the researcher counts off members of a population to achieve a sample, using a randomly chosen interval (every nth person, where n is a randomly selected number)

Purposive sampling
A biased sampling technique in which only certain kinds of people are included in a sampling. Only purposive when this is not a random sample.

Cluster sampling
A probability sampling technique in which clusters of participants within the population of interest are selected at random, followed by data collection from all individuals in each cluster.

self – selection
a term used when a sample is known to contain only people who volunteer to participate.
EX: online polling – can have bad external validity.
ex: parents asked ‘ was your child an early reader? ‘ a higher than reality percentage showed because parents who did have early readers were eager to answer this polling question. not representative.
A more realistic ex would be people who rate items or amazon, or books on goodreads

probability sampling/random sampling
every member of the population of interest has an equal chance of being selected for the sample, regardless of whether they are close by, easy to contact, or motivated to respond

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

What kind of sample is best for external validity?
Question 3 options:

a sample that can be collected as quickly as possible

a sample where each member of the population has an equal chance of being selected

a sample that includes the majority of the population

the largest sample possible

‘In most cases, researchers are not able to check accuracy of their samples’ estimates, because they hardly ever complete a full census of a population on the variable of interest.’
In research, is a bigger sample always a better sample? not necessarily.
A sample of 1,000 people, as long as it is random, allows them to generalize to the population quite accurately.

Which of the following is considered a representative sampling method?
Question 4 options:

snowball sampling

convenience sampling

self-selected sampling

systematic sampling

systematic sampling

Snowball sampling
a variation of purposive sampling that can help researchers find rare individuals, in which participants are asked to recommend a few acquaintances for the study.
Nonrepresentative

Which of the following is most important for enhancing external validity?
Question 5 options:

random sampling

random assignment

a large sample size

using measures that are valid and reliable

random sampling

Multistage Sampling
Two random samples are selected: a random sample of clusters, then a random sample of people within those clusters.

Stratified Random Sampling
A multistage technique in which the researcher selects particular demographic categories on purpose and then randomly selects individuals within each of the categories.

Dr. Jennings is doing a study on the experience of being a racial minority on a college campus. He goes to the Asian Student Association, Black Student Union, and Hispanic Student Group n his campus to recruit participants for his study. Dr. Jennings only includes Asians, African-Americans, and Hispanic participants in his study. What type of sampling is Dr. Jennings using?
Purposive Sampling

Beth is working on a research study focused on attention span in children. Among the participants, the group of 11-year old boys is underrepresented. Beth asks her 11-year old brother to distribute flyers about participation in the study to his male classmates and soccer team. What type of sampling is this?
Snowball

Which of the following is considered a biased sampling method?
-Convenience Sampling
-Cluster Sampling
-Stratified Random Sampling
-Simple Random Sampling
Convenience Sampling

A political research center obtains a list of phone numbers of all registered voters in Texas and uses a random number generator to select 1,000 of the phone numbers to call. They ask each voter which gubernatorial candidate they plan to vote for in the upcoming election. What is the population of interest that the research center wants to generalize to?
All registered voters in Texas

Dr. Rhodes is interested in how differing levels of light affect how people perceive color. He finds participants for this research study by making an announcement in several psychology classes at his University. What kind of sampling is Dr. Rhodes using?
Convenience Sampling

The superintendent of schools in a small town in Ohio made a lot of policy changes to the way school administrators worked in his district. A researcher at a nearby university wanted to look at what teachers in his district thought about the changes. The researcher made a list of all of the schools in the district and used a random number generator to select a sample of five schools from the district. Then the researcher interviewed each teach at each of those 5 schools. What sampling method did the researcher use?
Cluster sampling

A _____ is the entire set of people in which researchers are interested
Population

Mr. Stratford is the president of a national organization of lesbian, bisexual, gay, and transgender people in the United States. He wants to survey 1,000 members of his organization about the position they want the organization not to take on several political issues. He knows that transgender people make up only 5% of his organization. But he wants to make sure that their views are accurately represented. He decides that he will randomly sample 100 transgender members and then adjust the final results so that transgender people are weighted to their actual proportion in the organization. What type of sampling is Mr. Stratford using?
Oversampling

Which sample would be most likely to represent the population of American teenagers?
A cluster sampling of 1,000 teenagers from around the United States

Which of the following is most important for enhancing external validity?
Random sampling

What kind of sample is best for external validity?
A sample where each member of the population has an equal chance of being selected

A college administrator knows that 70% of the students at his college are from out of state, so he decides to make sure that he includes 70 out of state students and 30 in state students in his survey about admission practices at the college. He randomly selects 70 students from the out of state list and 30 students from the in state list. What sampling method is he using?
Stratified random sampling

_____ is when you study every member of a population
Census

A political research center obtains a list of phone numbers for all registered voters in Texas and uses a random number generator to select 1,000 of the phone number to call. They ask each voter which gubernatorial candidate they plan to vote for in the upcoming election. What sampling method is being used?
Simple random sampling

Which of the following is considered a representative sampling method?
Systematic Sampling

The campus safety committee has asked Professor Ibrahim to study bicycling on his campus. He trains two observers and has them observe the number of cyclists and their safety at various points around campus. He selects 10 observation locations at random from the places bicycles can be ridden on campus and five one-hour spans of time at random from daylight hours at each place. He had his observers make observations at each of the ten places for each of the five time spans. What type of sampling is he using?
Multistage sampling

The directors of an annual community concert want to find the musical preferences of the audience. The ushers place a survey card on every sixth seat beginning with the second seat (2 and 6 were chosen form a random number table). All of the cards are returned as the audience leaves. Which type of sampling is being used?
Systematic Sampling

Dr. Lawrence is the director of Counseling Services at her university. She is planning to conduct a survey of 100 students at the university to see how aware they are of the counseling services that are offered at the university. She wants the proportion of males and females in her sample to reflect the proportion in the university as a whole. Dr. Lawrence plants to stand in the Student Union and ask people to participate until she has given the survey to 55 females and 45 males. What type of sampling method is Dr. Lawrence going to use?
Quota Sampling

Mr. Stratford is the president of a national organization of lesbian, bisexual, gay, and transgender people in the United States. He wants to survey 1,000 members of his organization, but he wants to make sure that their views are accurately represented. He decides that he will randomly sample 100 transgender members and teh nadjust the final results so that transgender people are weighted to their actual proportion in the organization. Is Mr. Stratford collecting a representative sample?
Yes, because the transgender people in the final sample were sampled randomly from the population of transgender people in the organization

A sample is always ____ a population
smaller than

What sample size is often cited as the optimal balance between accuracy and effort?
1,000

The student government at a college is interested in determining how important intercollegiate sports are to the students there. Since all students have e-mail accounts, they are able to send a survey to all the students. About 50% of the students respond. Which is the most likely bias in this sample?
Self-selection bias

What kind of sample is best for external validity?
A sample where each member of the population has an equal chance of being selected

Dr. Rhodes is interested in how differing levels of light affect how people perceive color. He finds participants for this research study by making an announcement in several psychology classes at his university. Should Dr. Rhodes be concerned about using this sampling method?
No, because external validity probably doesn’t matter for the type of claim he is making

Dr. Lawrence is the director of Counseling services at her university. She is planning to conduct a survey of 100 students at the university to see how aware they are of the counseling services that are offered at the university. She wants to proportion of males and females in her sample to reflect the proportion in the university as a whole. Dr. Lawrence plants to stand in the student union and ask people to participate until she has given the survey to 55 females and 45 males. Is Dr. Lawrence collecting a representative sample?
No, because the participants are selected non-randomly