Rotatable Designs and Rotatability

Abstract

Choosing a suitable experimental design is an important step in the investigations of the factors that may influence one or more response variables. There are several criteria to keep in mind when the choice is made, one of which is rotatability . When a design is rotatable , it will produce information that predicts ŷ with the same precision at all points equidistant from the coded origin of the design. Another way of saying this is that the contours of V (ŷ), the variance of the predicted value, will be spherical about the design origin. In experimental practice, exact rotatability is not essential, but the knowledge of how to obtain it is useful in producing approximate rotatability while perhaps attaining other desirable design characteristics.

Desarrollo racional de sistemas terapéuticos nanométricos para el tratamiento de la epilepsia refractaria

“…El agregado de los puntos centrales y axiales en un DCC es útil para evaluar curvaturas en la superficie de respuesta, principalmente para el ajuste de estas superficies a modelos cuadráticos (Chauhan et al 2013). Una de las características principales de este diseño es su rotabilidad, es decir, el diseño debe poder predecir la variable respuesta �, con la misma precisión en todos los puntos equidistantes al origen del diseño (puntos centrales) (Draper 2008).…”