Principles of the experiment design

Reference books usually present experiment designs as recipes, one of which should be chosen for each experiment. This approach extends to teaching and leads the researcher to understand that he is limited to the use of these experiment designs. The consequences are the adaptation of research plans to this restrict set of designs and the adoption of inappropriate designs to achieve research objectives. This approach arose from the relatively simple calculations required to analyze the results of experiments with those designs at a time when computing resources were precarious. The evolution of computing resources no longer justifies the restriction to experiment designs that require easy calculations. These resources made possible the elaboration of designs with properties appropriate for efficient experiments. This article considers the properties that constitute principles of the experiment design that must be considered when planning the experiment. Compliance with these principles allows the researcher to elaborate the most appropriate experiment design for each experiment.