Which of the following best describes how to handle extraneous variabl

Which of the following best describes how to handle extraneous variables? (Choose all that apply.) The researcher:

a. can control all extraneous variables as long as they are identified.
b. can control for extraneous variables through study design.
c. must identify the main extraneous variables and control for them.
d. should include all extraneous variables in the data analysis to eliminate their influence.

ESSAYBID ANSWER

ANS: B, C
When contemplating the study design, it is helpful for the researcher to think of things that might influence the study, but are not part of the study. Sometimes there is not much the researcher can do about them. Other times the researcher can set up the study to eliminate them, making the sample as homogeneous as possible with the exception of what the researcher wants to explore.
The researcher needs to identify as many extraneous variables and control for them to reduce their effects on the results of the study.
There is no way to control for all extraneous variables.
Including extraneous variables in data analysis may actually increase their influence in the study.