Kevin is a member of the Nursing Research Council of the hospital. His first assignment is to determine the level of patient satisfaction with the care they received from the hospital. He plans to include all adult patients admitted from April to May, with an average length of stay of 3-4 days, first admission, and with no complications. Which of the following is an extraneous variable of the study?
A. Date of admission
B. Length of stay
C. Age of patients
D. Absence of complications
Correct Answer: C. Age of patients
An extraneous variable is not the primary concern of the researcher but has an effect on the results of the study. Adult patients may be young, middle, or late adults. Extraneous variables are those that produce an association between two variables that are not causally related.
Option A: The date of admission is an independent variable. An independent variable is a variable believed to affect the dependent variable. This is the variable that the researcher will manipulate to see if it makes the dependent variable change.
Option B: The length of stay is an independent variable because it can also affect the dependent variable, which is the level of satisfaction of the patients. To reiterate, the independent variable is the thing over which the researcher has control and is manipulating.
Option D: The absence of complications is another independent variable because it can also affect the level of satisfaction of the patients. The experiment’s dependent variable is the ball throwing, which will hopefully change due to the independent variable. The scientific sentence is, ‘You are going to manipulate an independent variable to see what happens to the dependent variable.’