Question 1

A scientific technique that allows a researcher to learn something about a population by studying a few members of that population is called:

Accepted Answer

Sampling involves selecting a small group of individuals (the sample) from a larger population and using that group to draw conclusions or make inferences about the population as a whole. This technique is commonly used in scientific research to save time and resources while still yielding accurate results.

Question 2

A researcher is interested in whether participants in a drug treatment program are successful in their rehabilitation. He asks for volunteers to participate in a long-term study of post-treatment success. Twenty of the 130 participants volunteer to participate in the four-year follow up study. The bias in this sampling plan is best described as:

Accepted Answer

A

Question 3

A researcher wants to study a drug use prevention program targeted at high school freshmen in Chicago. The student population is around 200,000 and is extremely diverse with respect to race, ethnicity, and socio-economic status. The researcher makes a list of all the high school freshmen in the city and randomly draws 100 names from the list. The bias in this sampling plan is best described as:

Accepted Answer

The bias in this sampling plan is selection bias because the sample is not representative of the population due to the small sample size and potential for certain groups to be overrepresented or underrepresented in the sample. The researcher should use a more representative sampling method to reduce bias and improve the generalizability of the results to the broader population.

Question 4

The measure of a sample's representativeness and therefore its ability to accurately predict conditions with the population from which it was collected is referred to as its:

Accepted Answer

The measure of a sample's representativeness and ability to accurately predict conditions in the population is indicated by its level of precision. This is because precision refers to the extent to which a measurement or sample is consistent, and a precise sample is more likely to be representative of the population from which it was collected. Accuracy indicator, estimated error, and overall reliability are related concepts but do not specifically address the issue of representativeness.

Question 5

What can be said about the following statement: Results from a non-probability sample can be inferred to the larger population from which the sample was obtained.

Accepted Answer

Non-probability samples do not allow for generalization to the larger population because they do not provide every individual in the population an equal chance of being selected, leading to potential biases.

Question 6

A researcher draws names out of a hat to see which police officers in a particular precinct will be interviewed for a study on workplace satisfaction. This probability sampling technique is best defined as:

Accepted Answer

Simple random sampling involves selecting items or individuals from a population at random, where each member of the population has an equal chance of being selected. In this scenario, the researcher is randomly selecting police officers from a particular precinct, ensuring that each officer has an equal chance of being chosen for the study. Therefore, simple random sampling is the most appropriate technique.

Systematic random sampling involves selecting every nth item or individual from a population, whereas cluster sampling involves randomly selecting groups or clusters from a population to be included in the sample. Stratified random sampling involves dividing a population into subgroups based on certain characteristics and then randomly selecting individuals from each subgroup. None of these techniques are being used in this scenario.

Question 7

A researcher randomly selects ten drug treatment centers in the state and then randomly selects twenty patients at each of the drug treatment centers to survey. This probability sampling technique is best defined as:

Accepted Answer

This is an example of cluster sampling because the researcher is selecting entire treatment centers (clusters) instead of individual patients, and then sampling all patients within each selected center.

Question 8

A researcher divides the residents of a low-income housing project into two groups: those age 30 and under, and those over age 30. Ten people from each group are randomly selected for interviews. This probability sampling technique is best defined as:

Accepted Answer

This is an example of stratified random sampling because the population is divided into two strata based on age and a random sample is taken from each stratum.

Question 9

A researcher selects every 20th name from a list of probation officers in the state to create a sample for a study of officer education and training. This probability sampling technique is best defined as:

Accepted Answer

The researcher is selecting every 20th name from a list, which is a form of systematic random sampling. This technique involves selecting every nth element from a list or population, where n is a fixed interval determined by the researcher.

Question 10

A researcher interviews a member of a dangerous religious cult that she has been introduced to. At the end of the interview, she asks for the name of other members of the cult that she might interview. This non-probability sampling technique is best defined as:

Accepted Answer

Snowball sampling is a non-probability sampling technique where participants are recruited through referrals from other participants. In this scenario, the researcher asks for referrals of other members of the cult, making it a snowball sample. Other options are not applicable to this scenario as there is no indication of convenience sampling or selecting typical or extreme cases.

Question 11

A researcher conducts an in-depth study of a town experiencing rapid population growth to understand the relationship between population growth and crime. This non-probability sampling technique is best defined as:

Accepted Answer

Extreme case sampling focuses on specific instances that are unusual or of particular interest, such as a town experiencing rapid population growth, to gain a deeper understanding of the phenomenon and its implications, such as its relationship with crime.

Question 12

A researcher writes a life history of a reformed repeat sex offender to see if the offender's life provides any insight into rare cases of rehabilitation among repeat sex offenders. This non-probability sampling technique is best defined as:

Accepted Answer

The answer of A researcher writes a life history of...

Question 13

Any condition that causes a sample to be less than representative of the population from which it came is referred to as:

Accepted Answer

Bias refers to any factor that causes a sample to differ from the population it is meant to represent, which can include errors and discrimination/prejudice. However, error, discrimination, and prejudice may not always specifically refer to issues with representativeness, while bias does.

Question 14

A complete list of the population from which a researcher will draw a sample is referred to as a sampling:

Accepted Answer

A sampling frame is a complete list of the population from which a researcher will draw a sample. A sampling plan refers to the specific method or strategy for selecting a sample from the population, a sampling scheme is a broader term that encompasses all aspects of the sampling process, and a unit refers to the individual elements or objects in the population being sampled.

Question 15

The individual units of analysis in a population that constitute a sample are called the:

Accepted Answer

The term "elements" is used in statistics to refer to individual units of analysis in a population that constitute a sample. While "cases" and "members" may also be used in some contexts, "elements" is the most common and accepted term. Therefore, B is the best choice.

Question 16

A police officer who draws ten business cards from a hat containing the business cards of 100 officers is conducting what type of sampling technique?

Accepted Answer

The police officer is randomly selecting 10 out of 100 business cards, which is a representative sample of the population of officers.

Question 17

A researcher who divides a population into two groups (male and female) and then randomly selects a sample from each group is conducting what type of sampling technique?

Accepted Answer

The researcher is dividing the population into two strata (male and female) and then randomly sampling from each stratum, which is called stratified random sampling. This technique ensures representation from each stratum and increases the precision and accuracy of the sample.

Question 18

After completing an in-depth interview with a burglar, a researcher who asks the burglar to give him the name of other burglars in the area is conducting what type of sampling technique?

Accepted Answer

The researcher is using snowball sampling, as they are asking the burglar to provide names of other burglars in the area, who they may know through their criminal network. This technique involves collecting referrals from initial participants to identify additional individuals to participate in the study.

Question 19

A researcher who interviews psychopaths who have murdered at least five people is using what type of sampling technique?

Accepted Answer

The researcher is using extreme case sampling as they are targeting a very specific and extreme subset of the population (psychopaths who have committed at least five murders). This type of sampling is often used in research that aims to study rare or extreme phenomena.

Question 20

The entire set of individuals that are relevant to a research project are called:

Accepted Answer

The term "population" refers to the entire set of individuals or objects that are relevant to a research question. The terms "sample" and "census" refer to subsets of the population, while "frame" refers to a list of the individuals or objects in the population.

Quiz 8: Sampling