When should a nurse researcher include an extraneous variable as ...

[cherise1989]

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

Question 2

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.

[wilsonbho]

Answer to Question 1

ANS: B

Feedback
A Excluding extraneous variables frequently limits a study's generalizability to a larger population. This is often necessary in order to have meaningful, unambiguous study outcomes.
B If the researcher believes that an extraneous variable is important to the outcome, it should be included in the design.
C Time and financial demands should not solely influence the inclusion of extraneous variables in a study's design.
D Extraneous or mediating variables are a concern only if they may influence the outcome of a study. If a variable has no relationship to the study's outcome, it would be superfluous to include it in the study design.

Answer to Question 2

ANS: A

Feedback
A Homogeneity of a sample is ensured by restricting eligibility criteria.
B Random assignment to experimental or control groups helps avoid bias but does not ensure homogeneity of the sample.
C Data collection by one researcher helps ensure consistency in data collection but does not ensure a homogenous sample.
D Uniform timing of data collection helps ensure consistency of data collection but does not ensure a homogeneous sample.