The number of individual scores that can vary without changing the sample mean. Statistically written as 'N-1' where N represents the number of subjects.
A variable whose effect on the response variable cannot be separated from the effect of the explanatory variable on the response variable. Note: Usually confounded variables are lurking variables but only a few lurking variables are also confounded.
Not dependent on or conditioned by or relative to anything else
The branch of statistics that includes numerical, graphical, and tabular methods for organizing and summarizing data