Question 1

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?

Accepted Answer

The murder event is an external event that occurred during the study period, which could influence the study's outcomes independently of the intervention being tested. This is known as a historical threat to internal validity because it involves specific events that occur between the first and second measurements but outside of the experimental manipulation.

Question 2

Why should a nurse researcher want to limit or eliminate extraneous variables in a study?

Accepted Answer

Extraneous variables are factors that can potentially influence the outcome of a study, but are not the focus of the research question. By limiting or eliminating extraneous variables in a study, nurse researchers can improve the internal validity of their findings, meaning they are more confident that the observed effects are due to the independent variable being studied, rather than alternative explanations. This is because extraneous variables compete with the independent variable as explanations for the study's outcome. By reducing the influence of extraneous variables, researchers can increase the likelihood of accurately attributing observed changes to the independent variable, which strengthens the study's conclusions.

Question 3

When reviewing a research report, the nurse determines that all aspects of a study systematically and logically follow from the research problem. Which condition has been met?

Accepted Answer

A

Question 4

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?

Accepted Answer

A mediating variable is a variable that explains the relationship between an independent variable and a dependent variable. In this case, the independent variable is the high dose of vitamin C and the dependent variable is the susceptibility to influenza.
The use of influenza vaccine could be a mediating variable because it is a known preventative measure against the flu. If a subject is already vaccinated, their susceptibility to influenza may be reduced regardless of their intake of vitamin C. Therefore, it could be important to control for this variable in the study to determine if high doses of vitamin C have a significant impact on susceptibility to influenza.
The subject's knowledge of vitamin C's functions, as well as their gender or marital status, are unlikely to have a direct impact on their susceptibility to influenza, and therefore would not be mediating variables in this study.

Question 5

How could a nurse researcher's use of a homogeneous sample weaken a research study?

Accepted Answer

Homogeneous samples are composed of individuals who share similar characteristics, such as age, gender, ethnicity, or health status. While homogeneous samples can increase the internal validity of a study by reducing extraneous variability, they may also weaken the external validity or generalizability of the findings. This is because a homogeneous sample may not represent the diversity of the population, and the findings may not be applicable to individuals who differ from the sample in terms of the excluded characteristics. For example, if a nurse researcher studies the effects of a new pain medication on a sample of young, healthy adults, the findings may not be relevant to older adults or individuals with comorbidities. Thus, the use of a homogeneous sample may limit the applicability of the findings to the broader population, and the nurse researcher should consider the trade-off between internal and external validity when selecting a sampling strategy.

Question 6

The issue of control would be less important in a quantitative study with which type of research design?

Accepted Answer

The answer of The issue of control would be less...

Question 7

How would a nurse researcher ensure that the sample used in a quantitative study is homogeneous?

Accepted Answer

Homogeneity refers to the similarity of the study participants in terms of the variables that are relevant to the research question being asked. In a quantitative study, homogeneity of the sample is important to ensure that the results are valid and can be generalizable to the population of interest.
One way to ensure homogeneity of the sample is to use eligibility criteria that limit extraneous variables that are relevant to the study. Eligibility criteria are the characteristics or conditions that participants must meet to be included in the study. By using eligibility criteria, the nurse researcher can ensure that the participants are similar in terms of the variables that are important for the study. For example, if the research question is about the effect of a medication on blood pressure, the eligibility criteria could include a specific range of blood pressure values. This would ensure that the participants are similar in terms of their blood pressure levels.
Random assignment (Option B) and collecting data at the same time of day (Option D) are not directly related to ensuring sample homogeneity. Random assignment is a method used to allocate participants to different treatment groups in a study and is not necessarily related to sample homogeneity. Collecting data at the same time of day may reduce the impact of diurnal variation, but it does not ensure that the sample is homogeneous in terms of the variables that are important to the study.
Assigning one research assistant to collect data from all subjects (Option C) is not a sufficient method to ensure sample homogeneity. It is important to use eligibility criteria to ensure homogeneity, as well as other sampling methods, such as stratified sampling, to ensure that the sample is representative of the population of interest.

Question 8

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?

Accepted Answer

The nurse researcher is using randomization, which involves assigning subjects to the experimental and control groups randomly in such a way that every subject in the population has an equal chance of being selected. Randomization helps to reduce the risk of bias in the study and increases the likelihood that any observed effects are due to the intervention being tested rather than other factors such as participant characteristics or confounding variables. Selection bias refers to a situation in which the selection of participants for a study is not random and is therefore subject to bias. Convenience sampling involves selecting participants who are readily available and willing to participate, which can introduce bias into a study. Internal validity refers to the degree to which a study accurately measures what it is intended to measure, and is not directly related to the method of participant selection.

Question 9

What is the overall purpose of the research design in a quantitative research study?

Accepted Answer

The overall purpose of the research design in a quantitative research study is to provide the plan for answering the research question. The research design outlines the methods and procedures that will be used to collect and analyze data in order to address the research question. It involves making decisions about the study's population, sample size, sampling method, data collection methods, and statistical analysis. The research design should be carefully constructed to ensure that the data collected will be reliable and valid, and that the results will provide a clear and accurate answer to the research question. While determining sample size, identifying the problem statement, and identifying gaps in the knowledge base are all important components of a research study, they are not the overall purpose of the research design in a quantitative research study.

Question 10

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?

Accepted Answer

The answer of A study is examining the effect of...

Question 11

A nurse researcher should consider mortality a threat to the study's internal validity for which of these reasons?

Accepted Answer

Mortality, in research terminology, refers to the dropout rate of participants from a study. When participants drop out, it can threaten the internal validity of the study because those who leave may have different characteristics or outcomes compared to those who remain, potentially biasing the results.

Question 12

For which of these reasons would a nurse researcher choose to assign subjects randomly to groups in a study?

Accepted Answer

Random assignment helps ensure that groups are representative of the larger population by minimizing selection bias, thus making the groups more comparable with respect to known and unknown variables.

Question 13

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?

Accepted Answer

The answer of A nurse is designing a study to...

Question 14

A nurse researcher can control for selection bias in a study by taking which of these actions?

Accepted Answer

Selection bias occurs when certain subjects are systematically excluded or included in a study. To control for selection bias, a nurse researcher can use defined selection criteria for approaching potential subjects. This ensures that subjects are selected in a systematic and objective way, rather than through subjective or arbitrary means. Allowing subjects to self-select or handpicking subjects can introduce bias, as certain groups may be more likely to participate or be excluded based on personal characteristics. Having someone else select the subjects can also introduce bias if that person is not using defined selection criteria. Therefore, using defined selection criteria is the best way to control for selection bias in a study.

Question 15

In which of these ways does the nurse researcher's literature review help select the appropriate study design?

Accepted Answer

The answer of In which of these ways does the...

Question 16

The measures used by a nurse researcher to maintain uniformity of conditions in a quantitative research study refer to which aspect of the study?

Accepted Answer

The measures used by a nurse researcher to maintain uniformity of conditions in a quantitative research study refer to the aspect of the study known as "control." In research, control refers to the actions taken by the researcher to minimize the influence of extraneous variables on the study results. This involves standardizing the procedures used in the study, controlling for confounding variables, and ensuring that all participants are treated equally. By maintaining control, the researcher can ensure that the study conditions are as uniform as possible, which increases the internal validity of the study results. Therefore, the correct answer is C) Control.

Question 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?

Accepted Answer

Option C represents a threat to internal validity called "contamination" or "diffusion of treatment" effect. It occurs when the treatment in one group (in this case, the videotape of discharge instructions) is inadvertently received by the participants in the other group (the control group). In this situation, patients in the experimental group discussed aspects of the videotape with patients in the control group, which could have influenced the outcomes and biased the results in favor of the experimental group. This would compromise the internal validity of the study, making it difficult to draw conclusions about the true effects of the treatment.
Options A and B do not represent a threat to internal validity. Including both men and women in the study (Option A) is not a threat to internal validity, but it could impact external validity (generalizability) if there are gender differences in the response to the treatment. Similarly, the fact that two new surgeons began performing CABG surgery during the study period (Option B) is not a threat to internal validity unless there are significant differences in the outcomes between the surgeries performed by the new surgeons and those performed by the original surgeons.
Option D represents a potential threat to external validity (generalizability) but not internal validity. The length of data collection in the videotape and control groups may affect the generalizability of the results if the outcomes change over time or if the study population changes during the data collection period. However, it does not affect the internal validity of the study or the validity of the causal inferences that can be drawn from it.

Question 18

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?

Accepted Answer

Feasibility refers to the practicality of conducting a study, and several factors can affect it. Among the options given, option B is the factor that would negatively affect the feasibility of this study. The potential study subjects represented less than 1% of hospital admissions during the year previous to the study. This factor would make it difficult to recruit an adequate sample size for the study, which could affect the statistical power and generalizability of the findings.
Option A is not a negative factor since having a high percentage of eligible participants is an advantage that can facilitate recruitment. Option C is an ethical consideration that would require alternative approaches to obtain informed consent, such as seeking permission from parents or legal guardians. Option D is not an issue related to feasibility, but it highlights the novelty and relevance of the study.

Question 19

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?

Accepted Answer

This action represents the manipulation of the independent variable, as the researcher is actively changing who receives the experimental treatment and who does not, to observe the effects of this intervention on an outcome.

Question 20

When should a nurse researcher include an extraneous variable as part of a study's design?

Accepted Answer

The answer of When should a nurse researcher include an...

Quiz 8: Introduction to Quantitative Research