Tools for Experimental Design Sizing // Sizes field experiments from uniformity-trial data, following the relationship between the coefficient of variation and plot size. Checks a trial for the spatial structure the sizing methods assume (semivariogram, Moran's I, kriged field map), summarises the coefficient of variation over every plot shape the grid admits, and estimates the optimal plot size by the modified maximum curvature method of Meier and Lessman (1971), by the linear response plateau (LRP) and quadratic response plateau (QRP) models, and by the closed form of Paranaiba, Ferreira and Morais (2009), which can be compared side by side. From the coefficient of variation at the optimum it derives the number of replications needed to detect a given difference between treatment means, as in Cargnelutti Filho and others (2014). Every method returns standardised diagnostic statistics, optional bootstrap uncertainty for the breakpoint, and publication-style plots.