Chapter 12: Sampling

Methods of probability sampling include what? A. Cluster B. Convenience C. Quota D. Purposive

A Cluster sampling is a method of probability sampling. Convenience sampling is a method of non-probability sampling. Quota sampling is a method of non-probability sampling. Purposive sampling is a method of non-probability sampling.

Which sampling strategy is considered to be easy in terms of drawing a sample? A. Convenience B. Quota C. Simple random D. Stratified random

A Convenience sampling is considered easy in terms of drawing a sample. Quota sampling is considered relatively easy in terms of drawing a sample. Simple random sampling is considered laborious in terms of drawing a sample. Stratified random sampling is considered time consuming in terms of drawing a sample.

Which sampling strategy is considered to have the greatest risk of bias of any strategy? A. Convenience B. Quota C. Simple random D. Stratified random

A Convenience sampling is considered to have the greatest bias of any sampling strategy. Quota sampling does not have the greatest risk of bias of any of the sampling strategies. Simple random sampling does not have the greatest risk of bias of any of the sampling strategies. Stratified random sampling does not have the greatest risk of bias of any of the sampling strategies.

When is bias introduced into a study? A. When sample selection is carried out inconsistently B. When subjects do not volunteer to participate C. When probability sampling techniques are used D. When the population is homogeneous

A Inconsistent sample selection jeopardizes the representativeness of the sample and introduces bias. Random sampling introduces the least amount of bias in the sample. Probability sampling introduces the least amount of bias in the sample. Homogeneity in the population reduces the likelihood of bias.

What sampling technique uses random numbers to select a sample from a list of possible subjects? A. Simple random sampling B. Stratified random sampling C. Non-probability sampling D. Cluster sampling

A One technique of randomly selecting a sample is to use random numbers and select from a list of all possible subjects. Stratified random sampling involves dividing the target population into strata or subgroups. Random sampling is not a type of non-probability sampling. Cluster sampling is a multistage process.

Which sampling strategy has bias that increases with the greater heterogeneity of the population? A. Purposive B. Quota C. Cluster D. Convenience

A Purposive sampling is known to have bias that increases with the greater heterogeneity of the population.

Which sampling strategy has very limited ability to generalize because the sample is handpicked? A. Purposive B. Quota C. Cluster D. Convenience

A Purposive sampling is known to have very limited ability to generalize because the sample is handpicked.

A researcher wanted to conduct a study of depression among men working in executive corporate positions. The researcher located 10 subjects by advertising and then invited each of those subjects to refer their acquaintances who met the study criteria. What is this sampling technique called? A. Snowballing B. Matching C. Clustering D. Systematic

A Snowballing refers to finding people who meet the study criteria through social networks. Matching refers to constructing an equivalent comparison sample group by filling it with subjects who are similar to each subject in the control group. Clustering refers to a multistage process of successive random sampling. There is no sampling technique called systematic.

A research study explored the meaning of health for migrant farmworker women in a southern state. A convenience sample of 20 migrant farmworker women was surveyed. What is the population of this study? A. Migrant farmworker women in Georgia B. Migrant farmworkers C. Migrant farmworker women D. Migrant farmworkers in Georgia

A The population of this study is migrant farmworker women in Georgia. The study looked only at migrant farmworker women, not at all migrant farmworkers. The study looked only at farmworkers in Georgia, not at those in any other state. The study looked only at migrant farmworker women, not at all migrant farmworkers in Georgia.

Voluntary participation in a study may result in a sample that feels strongly about the issue being studied. This issue occurs in which type of sampling method? A. Convenience sampling B. Probability sampling C. Stratified random sampling D. Cluster sampling

A When a researcher selects a sample on the basis of convenience, the individuals willing to participate may do so because of their strong feelings about the topic being studied. They might not be representative of the larger population. With probability sampling, each member of the population has an equal chance of being included, thereby reducing the likelihood of having an overrepresentation of people with specific opinions. With any type of random sampling, each member of the population has an equal chance of being included, thereby reducing the likelihood of having an overrepresentation of people with specific opinions. With any type of random sampling, each member of the population has an equal chance of being included, thereby reducing the likelihood of having an overrepresentation of people with specific opinions.

Which sampling strategy is considered relatively easy in terms of drawing a sample? (Select all that apply.) A. Purposive B. Quota C. Simple random D. Stratified random

A, B Purposive sampling is used to draw a highly unusual sample and therefore may not be relatively easy. Quota sampling is considered relatively easy in terms of drawing a sample. Simple random sampling is considered laborious in terms of drawing a sample. Stratified random sampling is considered time consuming in terms of drawing a sample.

Which statements are true about convenience sampling? (Select all that apply.) A. Convenience sampling is the most commonly used method of sampling. B. Convenience sampling is the strongest non-probability sampling strategy. C. Research consumers should be skeptical about the external validity of the finding. D. Convenience sampling provides level III evidence. E. A disadvantage is that it is difficult for the researcher to obtain subjects.

A, C The easiest and most commonly used method of sampling is convenience sampling. Convenience sampling is the weakest form of sampling strategy with regard to strength of evidence and generalizability and is at highest risk for problems with external validity. The risk of bias is higher than with any other type of sampling. Convenience sampling produces level VI evidence. An advantage of convenience sampling is that generally it is easier for the researcher to obtain subjects.

What should be considered when estimating a sample size? (Select all that apply.) A. The design of the study B. The time available for analyzing data C. The type of sampling procedure used D. The cost of collecting data E. Homogeneity of the attributes under investigation

A, C, D The design of the study helps determine the size of the sample that is necessary. The type of sampling procedure will influence the size of the sample. The cost of collecting data will influence the size of the sample. Because the sample size affects the strength of the evidence obtained, determination of the sample size should not depend on operational concerns. Heterogeneity of the attributes under investigation should be considered.

A random sample of U.S. hospitals is surveyed to discover their nurse-to-patient ratios. What is the sampling frame for this study? A. All nurses hired by hospitals B. All U.S. hospitals C. All patients of the sample hospitals D. Hospitals responding to the survey

B All U.S. hospitals will have an equal opportunity to be included in the study. The units of the population from which subjects will be selected will not be nurses hired by all U.S. hospitals. The units of the population from which subjects will be selected will not be all patients of the sample hospitals. The definition of sampling frame is a list of all of the units of the population studied.

Which population meets criteria for being most available for study? A. A target population B. An accessible population C. A convenience sample D. A representative population

B An accessible population is available for participation in a study. The target population might or might not be accessible. Although a convenience sample is available, it cannot be considered a population of the study. Representativeness is an important characteristic of a sample, not of a population.

A quota sampling technique introduces what type of bias? A. Internal validity B. External validity C. Face validity D. Content validity

B As with any non-probability sample, the quota strategy contains an unknown source of bias that affects external validity. A non-probability sample does not necessarily introduce problems with internal validity. Face validity refers to the expert opinion of the validity of the content of the data-collection instrument and does not refer to sampling techniques. Content validity refers to the validity of the content of the data-collection instrument and does not refer to sampling techniques.

In a nationwide study, a researcher collected blood samples from patients who had been diagnosed with clinical depression. The researcher also collected blood samples from each patient's nuclear family. Which sample technique did the researcher most likely use? A. Purposive B. Convenience C. Quota D. Random

B Because the population of patients diagnosed with clinical depression is not known, quota sampling and random sampling were not possible. There were few selection criteria, making purposive sampling unnecessary. The easiest and most commonly used sampling technique is convenience sampling. Because the total population of patients with clinical depression is not known, handpicking a "typical" sample would be impossible. Because the total population of patients with clinical depression is not known, handpicking a representative sample would be impossible. Because the population of patients diagnosed with clinical depression is not known, random sampling was not possible.

What do methods of non-probability sampling include? (Select all that apply.) A. Cluster B. Convenience C. Quota D. Purposive E. Stratified random

B, C, D Convenience sampling is a method of non-probability sampling. Quota sampling is a method of non-probability sampling. Purposive sampling is a method of non-probability sampling. Cluster sampling is a method of probability sampling. Stratified random sampling is probability sampling.

A nurse conducted a research study that compared patient outcomes (length of hospital stay and perceived knowledge of disease process) in groups of 12-year-old patients with a diagnosis of epilepsy. Which are delimitations of this study? (Select all that apply.) A. Gender B. Age C. Socioeconomic status D. Diagnosis

B, D Only 12-year-old patients were included. Only patients with a diagnosis of epilepsy were included. Attributes in subjects were not excluded or included such as gender or socioeconomic status.

Which sampling technique would the researcher most likely use to study specific characteristics of adult triplets who were raised separately? A. Convenience B. Quota C. Purposive D. Random

C A purposive sample is used when a highly unusual group is being studied. Because relatively few subjects will meet the sample criteria, another sampling technique will be more appropriate. The quota technique is used when there are many characteristics that must be represented in the sample. Random selection would not be useful in this study because of the rarity of the target population.

What is the most important characteristic of a sample? A. Delimitation B. Purposiveness C. Representativeness D. Accessibility

C A sample must have characteristics that are similar to the larger population. The term delimitation refers to the exclusion and inclusion criteria for sample selection. The term purposive refers to a sampling approach, not to a sample characteristic. Although it is easier to have a sample that is readily accessible, there is another, more important characteristic.

Which sampling method is considered to be either less or more time consuming depending on the strata? A. Purposive B. Quota C. Cluster D. Convenience

C Cluster sampling is considered to be less or more time consuming depending on the strata.

What is true about both non-probability sampling techniques and probability sampling techniques? A. Non-probability sampling techniques are more rigorous. B. Each element has an equal chance of being included in the study with either technique. C. Probability sampling more likely results in a representative sample. D. Generalizability of findings is not possible with either technique.

C Probability, or random, sampling is more likely to provide a representative sample. Probability sampling is more rigorous. Only with probability sampling does each element have an equal chance of being included in the study. Generalizability is possible with probability sampling.

What is the purpose of establishing inclusion and exclusion criteria? A. To randomize sample selection B. To delineate an accessible population C. To control for potential bias D. To clarify the research question 3.

C To control for extraneous variables and ensure a representative sample, inclusion and exclusion criteria are carefully established. Selection criteria do not affect randomization of subjects. Selection criteria do not necessarily ensure accessibility of the population. Selection criteria should be consistent with the research questions, but they do not clarify any part of the research question.

When is purposive sampling most useful? A. When few people are willing to participate B. When members of the target population are heterogeneous C. When a highly unusual group is being studied D. When many subjects drop out of a study before it is completed

C When few people meet the selection criteria, researchers often form a sample from all those eligible people who are willing to participate. If few people are willing to participate, a convenience sampling technique is most useful. Random sampling techniques are best to use with heterogeneous populations. In quantitative research, sample selection occurs before data collection begins.

Which sampling strategy is considered laborious in terms of drawing a sample? (Select all that apply.) A. Convenience B. Quota C. Simple random D. Snowballing

C, D Simple random sampling is considered laborious in terms of drawing a sample. Stratified random sampling is considered time consuming and laborious in terms of drawing a sample. Convenience sampling is considered easy in terms of drawing a sample. Quota and snowballing sampling is considered relatively easy in terms of drawing a sample.

What can jeopardize the representativeness of the sample regardless of the technique used? (Select all that apply.) A. A large sample size B. Equal representation of each sample subset C. Sample heterogeneity D. Subjects dropping out of the study E. Ability to replicate the study population

C, D, E When the sample is heterogeneous, its representativeness is jeopardized. A high attrition rate can jeopardize the representativeness of the sample. A large sample size enhances the representativeness of the sample. An equal representation of each sample subset enhances the representativeness of the sample. Being able to replicate the study population enhances the study.

Which sampling strategy is considered to be easy in terms of ease of drawing the sample? A. Purposive B. Quota C. Cluster D. Convenience

D Convenience sampling is considered to be easy in terms of ease of drawing the sample.

Which sampling strategy has a greater risk of bias as compared to other sampling strategies? A. Purposive B. Quota C. Cluster D. Convenience

D Convenience sampling is known to have a greater risk of bias than any other sampling strategy.

Which sampling strategy is considered time consuming in terms of drawing a sample? A. Convenience B. Quota C. Simple random D. Stratified random

D Stratified random sampling is considered time consuming in terms of drawing a sample. Convenience sampling is considered easy in terms of drawing a sample. Quota sampling is considered relatively easy in terms of drawing a sample. Simple random sampling is considered laborious in terms of drawing a sample.

To conduct a practice analysis of nurse aides, a researcher uses the outlined steps to select a sample of nurse aides: 1. Obtaining a random sample of all hospitals in the United States. 2. Acquiring a list of every aide working in those hospitals 3. Randomly selecting two aides from each hospital. What is this sampling technique used? A. Quota sampling B. Stratified random sampling C. Purposive sampling D. Cluster sampling

D The sample for this study was chosen by "clustering" each level of sample selection. In quota sampling, subjects are hand-selected to ensure a proportional number of subjects with selected characteristics. In stratified random sampling, the population is divided into strata, or subgroups, before random selection of subjects. A purposive sample is used when a highly unusual group is being studied.