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

Question

Quizplus · Accepted Answer

By using eligibility criteria, the nurse researcher can limit the inclusion of participants who may introduce extraneous variables that may muddle the study's findings. By ensuring that the sample is homogeneous, the researcher can increase the internal validity of the study, which can ultimately enable the identification of causal relationships. Random assignment (B) is a method that is commonly used in experimental studies to control for extraneous variables; it does not guarantee homogeneity of the sample. Assigning one research assistant to collect data from all participants (C) may introduce bias if the assistant interacts differently with participants in the control versus experimental group. Collecting data from all participants at the same time of day (D) may be useful in controlling for some extraneous variables, such as circadian rhythms, but it may not guarantee homogeneity of the sample.

How Would a Nurse Researcher Ensure That the Sample Used