CH 12

12. The primary characteristic of a probability sample is considered to be what? a. Self-selection of subjects b. Random selection of the sample c. Subjects handpicked by the researcher d. Representation of proportional segments of the population

B The primary characteristic of a probability sample is random selection.

6. A nurse researcher should be concerned about establishing clear eligibility criteria for inclusion in a study sample because such criteria will do what? a. Increase the homogeneity of the sample b. Decrease the homogeneity of the sample c. Increase the size of the sample d. Decrease the size of the sample

A Clear eligibility criteria are designed to increase the homogeneity of the sample.

10. A nurse researcher would hesitate to use nonprobability sampling because: a. It will result in reduced or limited generalizability. b. Informed consent must be obtained. c. It will require large, unmanageable sample sizes. d. Sample sizes are too small for most methods of statistical analysis.

A Nonprobability sampling reduces or limits generalizability.

17. A nurse researcher can most accurately use the technique of power analysis to do what? a. To estimate sample size b. To establish sampling strata c. To assign subjects randomly d. To analyze sample representativeness

A Power analysis is a statistical procedure used to estimate needed sample size.

1. What is the process of selecting representative units of a population for study in a research investigation? a. Sampling b. Snowballing c. Delimination d. Random assignment

A Sampling is the process of selecting representative units of a population for a research study.

18. A nurse researcher should be particularly concerned about having a small sample size for which reason? a. There is increased risk of obtaining a nonrepresentative sample. b. There is increased risk of a study subject interacting with another study subject. c. There is increased potential for loss of confidentiality. d. There is increased regression toward the mean.

A Small sample sizes tend to increase the risk of a sample being nonrepresentative.

13. A nurse researcher opts to use a stratified sample in a research study for which reason? a. The sample population is divided into subsets that are homogeneous for a particular trait or feature. b. The sample population is divided into subsets for random assignment into an intervention or a usual-care group. c. The sample population is randomly assigned to a specific subgroup that will vary from the others on the basis of type of treatment. d. The sample population is randomly assigned to a specific subgroup that will vary from the others on the basis of treatment duration.

A The major characteristic of a stratified sample is that selected subjects represent population subgroups that are homogeneous.

1. What are types of nonprobability of sampling? (Select all that apply.) a. Purposive b. Quota c. Stratified random d. Multistage (cluster) e. Convenience

A,B,E Purposive sampling is a nonprobability type. Quota sampling is a nonprobability type. Convenience sampling is a nonprobability type.

3. The nurse researcher is attempting to develop a purposive sampling strategy as part of a research study. What criteria will be used to determine whether the strategy is purposive? (Select all that apply.) a. Validation of scale with a known-group technique b. Focus of study population relates to specific diagnosis c. Focus of study population relates to broad, general topic d. Effective posttesting of instruments e. Collection of exploratory data f. Collection of descriptive data

A,B,E,F This would be a criterion used to determine whether the sampling strategy is purposive.

19. A research consumer should evaluate sample size in a research report by doing what? a. By asking how many assistants were involved in data collection b. By asking how representative the sample is relative to the target population c. By asking how great the outcome difference is between or among study groups d. By asking how many previous studies the researcher has conducted on similar topics

B A major factor to be evaluated about sample size is how representative of the population the sample is.

7. A nurse researcher should attempt to clearly specify exclusion criteria for a study sample because such criteria will do what? a. Limit the time needed to complete the study b. Reduce the effect of extraneous variables on the accurate evaluation of the outcome variable c. Eliminate the outside influences and inferences regarding the effectiveness of a behavioral intervention d. Ensure that an adequate sample size is accrued to meet assumptions for accurate statistical analysis

B Exclusion criteria are designed to control sample characteristics and thereby reduce the potential effect of extraneous variables on the outcome variable.

4. Which statement is most accurate regarding inclusion and exclusion criteria? a. These criteria are not needed when the population being studied is composed of events. b. These criteria serve to ensure that the characteristics of the sample and the population are congruent. c. Inclusion criteria are used to define the independent variables, and exclusion criteria are used to define dependent variables. d. Inclusion criteria are used to define the dependent variables, and exclusion criteria are used to define independent variables.

B Inclusion and exclusion criteria are designed to keep the population and sample characteristics congruent.

14. The researcher used word of mouth to accrue a sample of participants. This is most accurately referred to as what? a. Referral b. Networking c. Recruitment d. Quasi-probability

B Networking is a sampling strategy using word-of-mouth via social networks.

3. A nurse researcher has made a generalization on the basis of the experience of a small number of participants. What will the result of this be? a. The small sample will invalidate the hypotheses. b. The researcher will be unable to eliminate his or her bias. c. The data obtained from a small number will inadequately represent the phenomenon. d. The small number of participants will increase the threat to internal validity influenced by history.

C A too-small sample may inadequately represent the phenomenon and threaten valid conclusions.

5. What can a nurse researcher use to restrict the study population to homogeneous groups of subjects? a. Sampling b. Self-selection c. Eligibility criteria d. Defining study limitations

C Eligibility criteria restrict or control the homogeneity of subjects in relation to the population.

15. The nurse researcher selects matching as a technique in a research study. What does the technique of matching in a sampling strategy contribute to the research? a. Improved overall design of the study b. Elimination of the need for a control group c. Increased equivalency of the comparison group d. Reduced sample size; subjects serve as their own controls

C Matching is a special strategy used to construct an equivalent comparison group.

2. The nurse researcher is deciding on a sampling strategy for the research study. Which type(s) of strategies would be considered to be probability sampling strategies? (Select all that apply.) a. Convenience b. Quota c. Simple random d. Cluster e. Purposive f. Stratified random

C,D,F This is a probability sampling strategy.

16. The nurse researcher can most accurately determine sample size by considering what? a. The stamina of the researcher in data collection b. The importance of the independent variable c. The age of the potential subjects d. The design of the study

D A major factor determining sample size is the type of design used.

2. How should a nurse researcher expect a sample to differ from a population? a. A sample can mean objects or events, whereas population refers to individuals or groups of people. b. A population has a broad set of defining characteristics, and a sample has a narrow set of defining characteristics. c. A population is a representative segment of a defined sample. d. A sample is a representative segment of a defined population.

D A sample is a set of elements or segments of a specified population.

11. Which type of sampling is most at risk for sample bias? a. Quota b. Random c. Purposive d. Convenience

D Convenience sampling is most at risk for sample bias.

20. Which statement regarding sample size is most accurate? a. Studies with smaller sample sizes have more accurate results. b. Studies with smaller sample sizes are more likely to be representative of the target population. c. Studies with larger sample sizes have more accurate results. d. Studies with larger sample sizes are more likely to be representative of the target population.

D In general, studies with larger sample sizes are more representative of the population.

8. The nurse researcher knows that a sample is representative of a population when which statement is true? a. The sample is homogeneous. b. All units of a population are included. c. The most readily accessible persons are used as subjects. d. The characteristics of the sample closely approximate those of the population.

D The foremost criterion in evaluating a sample is its representativeness.

9. How can a nurse researcher tell the difference between an accessible population and a target population? a. The accessible population meets the inclusion criteria, and the target population meets the exclusion criteria. b. The target population meets the inclusion criteria, and the accessible population meets the exclusion criteria. c. The accessible population represents the entire set of cases the researcher wishes to study, and the target population represents that part of the accessible population that could feasibly be included in the study. d. The target population represents the entire set of cases the researcher wishes to study, and the accessible population represents that part of the target population that could feasibly be included in the study.

D The target population is the entire set of cases the researcher wants to study; the accessible population meets population criteria and is available for study.