When setting up a scientific study it is important to ensure that variables do not confound each other. This will occour when a variable correlates either positively or negatively with both the dependent and the independent variable. This relationship can cause a researcher to develp a false analysis from the results gained. It is not always possibe to remove all variables, especially outside of
. a lab situation. Experimental designs need to be carefully planned to eliminate the problem of the confounding variable. In this way many of the worst confounding varibales can be filtered out.
