Abstract
A confounding variable is a variable that is associated with both the independent and the dependent variable and thus obscures or accentuates the relationship between the two. In experimental research, researchers are faced with a confoundation if the experimental manipulation(s) did inadvertently affect other variables. Therefore, in order to be able to draw valid causal conclusions researchers have to conduct (a) confoundation check(s). Crucial to the performance of such tests is their ordering and timing.
Hofer, Matthias