In the scientific method, an experiment (Latin: ex- periri, "of (or from) trying") is a set of observations performed in the context of solving a particular problem or question, to retain or falsify a hypothesis or research concerning phenomena. The experiment is a cornerstone in the empirical approach to acquiring deeper knowledge about the physical world. Design of experiments · That the independent variable is the only factor that varies systematically in the experiment; in other words, that the experiment is appropriately controlled - that confounding variables are eliminated; and · That the dependent variable truly reflects the phenomenon under study (a question of validity) and that the variable can be measured accurately (i.e., that various types of experimental error, such as measurement error can be eliminated).In a pure application of the scientific method, hypotheses are tested by critical ex