Abstract
An experiment involves manipulating or changing a variable or variables to see how the changes affect some other variable or variables, while eliminating or controlling the effects of other extraneous or confounding variables. The variable manipulated is called the independent variable. The variable upon which the possible effect of the change is measured is called the dependent variable. An experimental design is a procedure for ensuring that a change in a dependent variable may be attributed only to a change in an independent variable. Essentially, experimental design arrangements are intended to ensure that nothing other than the independent variable could have caused the observed changes in the dependent variable.
