That which the experimenter changes to see how it affects other factors is called the

dependent variable
controlled variable
independent variable
experimental variable

Only twenty percent of your mail surveys are returned. Why might conclusions drawn from these surveys be flawed?

A low response rate usually indicates that your questions are not objective.
The people who returned the survey probably do not represent the general population.
A low response rate usually means your questions are outdated.
all of the above

Question

That which the experimenter changes to see how it affects other factors is called the
 	
	dependent variable
	controlled variable
	independent variable
	experimental variable

Only twenty percent of your mail surveys are returned. Why might conclusions drawn from these surveys be flawed?
 	
	A low response rate usually indicates that your questions are not objective.
	The people who returned the survey probably do not represent the general population.
	A low response rate usually means your questions are outdated.
	all of the above

shane_b · Answer

For the first one, maybe this will help:

"The independent variable is typically the variable representing the value being manipulated or changed and the dependent variable is the observed result of the independent variable being manipulated. "

I'm not sure about the second...I'd say the real answer is that 80% of the people are tired of taking surveys :)