CH 8 e

1. The measures used by a nurse researcher to maintain uniformity of conditions in a quantitative research study refer to which aspect of the study? a. Accuracy b. Methods c. Control d. Validity

C (Control is the term used for measures taken by the researcher to keep the conditions of a study uniform.)

10. Why should a nurse researcher want to limit or eliminate extraneous variables in a study? a. More research questions would be required to account for the extraneous variables. b. Extensive statistical analysis would be required to justify the presence of extraneous variables. c. Extraneous variables compete with the independent variables as explanations of the study's outcome. d. Manipulation of the extraneous variables increases the risk for researcher bias in the study's outcomes.

C (Extraneous or mediating variables interfere with analyzing the effect of the independent variables on the dependent variable.)

15. A nurse researcher assigns subjects to experimental and control groups in such a manner that each subject in a population has an equal chance of being selected. What is the researcher using? a. Selection bias b. Convenience sampling c. Randomization d. Internal validity

C (Randomization is the process of obtaining subjects so that each has an equal chance of being selected for experimental or control groups.)

20. A nurse researcher can control for selection bias in a study by taking which of these actions? a. Allow subjects to self-select into an experimental or a control group b. Handpick the subjects for group assignment c. Use defined selection criteria for approaching potential subjects d. Have someone other than the researcher select the subjects for the study

C (Selection criteria (inclusive and exclusive) that are consistently applied help obtain a representative sample and decrease the risk of selection bias.)

4. When reviewing a research report, the nurse determines that all aspects of a study systematically and logically flow from the research problem. Which condition has been met? a. Accuracy b. Feasibility c. Internal validity d. External validity

A (Accuracy indicates that all aspects of a study systematically and logically flow from the research question.)

5. Which factor is most likely to be a mediating variable in a study to determine if high doses of vitamin C help reduce the subjects' susceptibility to influenza? a. The subjects' use of influenza vaccine b. The subject' knowledge of vitamin C's functions c. The gender of the potential subjects d. The marital status of the potential subjects

A (An extraneous or mediating variable is one that interferes with the operations of the variables being studied, such as the study's outcome, which is susceptibility to influenza.)

12. A study is examining the effect of a new antilipemic drug, compared with placebo, on lipoprotein levels in postmenopausal women. Which of these actions represents the researcher's attempt at constancy in data collection to control extraneous variables? a. Drawing the serum lipoprotein levels of all subjects at the same time of day b. Having the same phlebotomist draw serum lipoprotein levels of all subjects c. Using the same room for drawing blood for lipoprotein levels of all subjects d. Ensuring that all subjects are postmenopausal women taking lipid-lowering medication

A (Constancy in data collection (e.g., identical timing of collecting blood samples) helps maintain control in the research design because lipid levels may fluctuate throughout the day.)

16. The issue of control would be less important in a quantitative study with which type of research design? a. Exploratory b. Experimental c. Correlational d. Randomized clinical trial

A (Control is less important in exploratory studies because the researcher is investigating an area in which little literature exists.)

8. How would a nurse researcher ensure that the sample used in a quantitative study is homogeneous? a. Use eligibility criteria to limit extraneous variables relevant to the study. b. Randomly assign subjects to either the experimental or the control group. c. Assign one research assistant to collect data from all subjects. d. Collect data from all subjects at the same time of day.

A (Homogeneity of a sample is ensured by restricting eligibility criteria.)

22. Which of these situations describes a reactive (Hawthorne) effect? a. Control subjects in an intervention study to reduce anxiety also experience a reduction in anxiety. b. The subjects in an intervention support group continue the support group after the study has ended. c. Subjects become concerned after learning that they received a placebo, not the treatment, during the study. d. Study subjects want to know the outcomes of the study after it is completed.

A (Reactivity occurs when control subjects respond to the investigator not because of the treatment but because of the fact they were being studied.)

24. What action by a nurse researcher will help eliminate bias on the dependent variable? a. Establishing strict eligibility criteria for the study participants b. Ensuring that all data are collected by a single researcher c. Formulating at least two hypotheses for each research question d. Developing a strong theoretical framework for the study

A (Strict eligibility criteria help reduce extraneous or mediating variables that compete with the study (independent) variables for impact on the dependent variable.)

14. For which of these reasons would a nurse researcher choose to assign subjects randomly to groups in a study? a. To help ensure that all groups within a study are representative of the larger population b. To increase the chance that the study groups will be different from each other with regard to extraneous variables c. To help ensure that current events do not influence the outcomes of the study d. To eliminate the need for establishing specific study criteria and subject eligibility

A (The purpose of randomization is to help ensure that subjects in the study's groups represent the larger population.)

6. A nurse researcher is designing a quantitative research study involving a specific group of patients admitted to local hospitals. Which factor would negatively affect the feasibility of this study? a. The local region has a high percentage of families that could participate in the study. b. Potential study subjects represented less than 1% of hospital admissions during the year previous to the study. c. Study participants who were hospitalized children younger than 5 years could not give direct informed consent to participate in the study. d. A comprehensive review of the literature revealed no studies were conducted that examined this question during the past 15 years.

B (Feasibility refers to the pragmatic considerations of a study -e.g., availability of subjects, cost.)

9. How could a nurse researcher's use of a homogeneous sample weaken a research study? a. By decreasing the reliability of the findings b. By decreasing the generalizability of the findings c. By increasing the number of subjects needed to reach statistical significance d. By increasing the risk that the findings were the result of chance alone

B (Homogeneity of a sample can decrease the generalizability of the findings to other populations.)

11. When should a nurse researcher include an extraneous variable as part of a study's design? a. When excluding the variable would limit the study's generalizability b. When the variable is an important consideration for the study's outcome c. When the researcher is limited by time or monetary constraints d. When it would not make a difference in the overall study outcome

B (If the researcher believes that an extraneous variable is important to the outcome, it should be included in the design.)

3. In which of these ways does the nurse researcher's literature review help select the appropriate study design? a. By enlarging the scope of the study's hypotheses b. By objectively assessing available knowledge of the area c. By comparing current findings with previous study findings d. By ensuring faithfulness to the study's purpose

B (Objectivity in the conceptualization of the research question is derived from a thorough review of the literature.)

19. A nurse researcher should consider mortality a threat to the study's internal validity for which of these reasons? a. There is concern that the intervention may have harmful effects on subjects. b. Those who dropped out of the study may be different than those who remained in the study. c. Those who participated in the study may have died as a result of being in the study. d. There is concern that the design is inappropriate for the study question if a large number of participants drop out of a study.

B (Subjects who drop out or who are otherwise lost from a study may differ in some important way from remaining subjects and therefore threaten internal validity.)

7. A nurse is designing a study to determine whether a videotape or a written pamphlet is more effective in teaching young women how to perform breast self-examination (BSE). Which of these actions would provide the best control for a mediating variable? a. Include identical content in both BSE teaching methods b. Exclude subjects who already perform BSE on a regular basis c. Limit the study subjects to women who are heterosexual d. Determine what breast cancer means to the individual participants

B (Subjects who were already performing BSE would not be appropriate to include in the study.)

17. Which situation represents a threat to internal validity in an experimental study measuring the effect of a videotape of discharge instructions for patients who underwent coronary artery bypass graft (CABG) surgery? a. Both men and women undergoing CABG surgery were included as subjects in the study. b. Two new surgeons began performing CABG surgery during the study period. c. Patients in the experimental group discussed aspects of the videotape with patients in the control group. d. Data collection for the videotape and control groups took 1 year.

C (Sharing aspects of the videotape with control group members interferes with interpretation of the true effect of the independent variable on the dependent variables.)

13. A nurse researcher assigns half a study sample to an experimental group and the other half to a control group. What does this action represent? a. Instrumentation of the independent variable b. Manipulation of the mediating variable c. Elimination of the mediating variable d. Manipulation of the independent variable

D (Administration of a treatment or intervention to an experimental (treatment) group and not to a control group represents manipulation of the independent variable.)

21. External validity refers to which of these issues? a. The relationship existing between the independent variable and the study outcomes b. The influence of a specific event on the independent variable c. The degree to which extraneous or mediating variables interfere with the study outcomes d. The degree to which findings are generalizable to populations beyond those studied

D (External validity deals with possible problems of generalizability of the investigation's findings to other populations or environments.)

23. A nurse researcher is investigating the effect of type of operating room mattress and surgical position on tissue interface pressures in healthy young adults. Which component of research is most affected by the choice of subjects? a. Mortality b. Instrumentation c. Internal validity d. External validity

D (Subject selection affects external validity (generalizability), especially because most surgical patients are not healthy young adults.)

18. The nurse researcher designed a study examining anxiety among elementary school children. If a widely publicized murder of a child occurred in the city during the time frame of the study, what type of threat to internal validity would the murder represent? a. Maturation b. Instrumentation c. Selection bias d. Historical

D (The murder would represent a historical event threatening internal validity.)

2. What is the overall purpose of the research design in a quantitative research study? a. To determine sample size b. To identify the problem statement c. To assist the researcher in identifying gaps in the knowledge base d. To provide the plan for answering the research question

D (The purpose of the research design is to provide the plan for answering the research questions.)