Abstract

Basic concepts of experimental research, such as experimental factor, experimental unit and experimental error, are vaguely, imprecisely and inconsistently defined in the literature. This deficiency of literature is extended to teaching. This is the main source of the misunderstanding of these concepts by researchers and the consequent failures that imply the derivation of biased inferences from the experiment. This article presents a rational formulation particularly of the concepts of experimental factor, experimental unit and experimental error, coherent with their meanings in the process of the experiment.

Keywords: Experimental research; Planning of experiments; Basic concepts of experiment; Inferences from experiments