Question 1

A researcher wants to study adolescents who are homeless. He builds his sample by searching the streets, identifying an adolescent to interview, and then, asks the adolescent where the researcher can find another homeless adolescent to interview. What sampling method did this researcher use?

Accepted Answer

The researcher is using snowball sampling, where existing study subjects recruit future subjects from among their acquaintances, which is common in hard-to-reach populations like homeless adolescents.

Question 2

In one-stage cluster sampling, the random selection is done at the level of the:

Accepted Answer

In one-stage cluster sampling, the random selection is done at the level of the cluster unit.

Question 3

A researcher wants to study how children acquire a particular strategy to solve word problems. He chooses participants by screening children to determine if they already know the strategy. He chooses only those who have not learned the strategy yet. What sampling method did this researcher use?

Accepted Answer

The researcher is using purposive sampling because he is intentionally selecting participants who have not yet learned the strategy, based on specific criteria.

Question 4

A major disadvantage of convenience sampling is that:

Accepted Answer

Convenience sampling often leads to sampling bias because the sample is not randomly selected, making it difficult to generalize the results to the entire population.

Question 5

Snowball sampling is advantageous when one is:

Accepted Answer

Snowball sampling is particularly useful for accessing hard-to-locate or hidden populations, as it relies on referrals from initial subjects to recruit additional participants.

Question 6

A researcher is interested in studying a nationwide representative sample of the United States. She randomly chooses places to study using census tracts. She then randomly samples within each census tract from among the households within those tracts. What sampling method did this researcher use?

Accepted Answer

The researcher used a two-stage cluster sampling method by first randomly selecting census tracts (clusters) and then randomly sampling households within those selected tracts.

Question 7

Snowball sampling occurs when:

Accepted Answer

Snowball sampling is a non-probability sampling technique where existing study subjects recruit future subjects from among their acquaintances, leading to a growing sample size.

Question 8

In two-stage cluster sampling, random selection is done:

Accepted Answer

In two-stage cluster sampling, random selection is done in both stages: first, clusters are randomly selected, and then, within those clusters, individual elements are randomly selected.

Question 9

Which of the following is not true about stratified random sampling?

Accepted Answer

In stratified random sampling, the proportions of groups in the sample do not always have to match their population proportions, especially in disproportional stratified sampling where subgroups are intentionally overrepresented for analysis purposes.

Question 10

"Probability proportional to size" means:

Accepted Answer

In "probability proportional to size" sampling, the probability of selecting a cluster is directly related to its size, meaning larger clusters have a higher chance of being selected.

Question 11

When people with specific characteristics are recruited into a sample so that particular groups can be studied, this is called:

Accepted Answer

Purposive sampling involves selecting individuals with specific characteristics to ensure that particular groups are represented in the study, allowing for focused analysis on those groups.

Question 12

When a researcher looks for a certain number of people with a particular characteristic to serve in her sample, and she recruits such individuals until she has the number she wants, this is known as:

Accepted Answer

Quota sampling involves selecting a specific number of participants with certain characteristics to ensure that the sample represents those characteristics.

Question 13

An educational psychologist is interested in the effects of mnemonics on learning words lists. He asks for volunteers from a Psychology-101 class to find 50 volunteers to participate in his study. What sampling method did this researcher use?

Accepted Answer

The researcher used a convenience sample by selecting volunteers from a readily available group, the Psychology-101 class.

Question 14

Carly drew a sample by first identifying a comprehensive set of subgroups based on one or more variables, and then individuals were randomly selected from each of those subgroups. Carly used the technique known as:

Accepted Answer

Stratified random sampling involves dividing the population into subgroups (strata) and then randomly selecting samples from each subgroup.

Question 15

When a researcher uses a participant group primarily because of availability, this is called:

Accepted Answer

Convenience sampling is a non-probability sampling method in which participants are selected based on their availability and willingness to participate in the study.

Question 16

One advantage of cluster sampling is that:

Accepted Answer

Cluster sampling allows researchers to sample groups or clusters of a population, which means they do not need a complete list of all population members, just a list of clusters.

Question 17

An environmental action group is interested in how many people will participate in a recycling program in a particular town. They obtain the entire list of households in the town, and they assign each household a number from 1 to 3000 (the number of households in the town). They then use a computer to generate a list of 500 random numbers ranging from 1 to 3000. Using the list of random numbers, they draw a sample of 500 people to question about their use of the recycling program. What sampling method did this group use?

Accepted Answer

Simple random sampling is a method of selecting a sample from a population in which each member of the population has an equal chance of being selected. In this case, the environmental action group used a computer to generate a list of 500 random numbers ranging from 1 to 3000. This ensured that each household in the town had an equal chance of being selected for the sample.

Question 18

A researcher is interested in surveying physicians from a local medical society to examine their continuing education needs. He decides that she will draw a sample that contains physicians from a variety of different subspecialties. He divides the list of the population up by specialty, and then he randomly selects the number of physicians within each specialty in proportion to their percentage in the population. What is this type of sampling?

Accepted Answer

This is stratified random sampling, where the population is divided into subgroups (strata) based on a characteristic (in this case, specialty), and random samples are taken from each stratum in proportion to their representation in the population.

Question 19

For her thesis, Kathryn recruited individuals who were easily available. This is known as:

Accepted Answer

Convenience sampling involves selecting participants who are easily accessible to the researcher, which is what Kathryn did.

Question 20

Disproportionate stratified random sampling:

Accepted Answer

Disproportionate stratified random sampling involves selecting samples from different strata in varying proportions, often to ensure that smaller groups are adequately represented for meaningful analysis.

Quiz 10: Sampling in Quantitative, Qualitative, and Mixed Research