01191naa a2200145 a 450000100080000000500110000800800410001910000200006024500990008026000090017952007910018865300130097970000200099277300330101216487702000-04-27 1958 bl --- 0-- u #d1 aHATHEWAY, W. H. aEfficient estimation of the relationship between plot size and the variability of crop yields. c1958 aThe optimum size of plot in field experimentation depends on the relationship between fixed costs and costs varying with number of units, and on soil variability. Perhaps the most useful measure of soil hetero geneity yet devised is that of Smith [1938], who showed empirically that the logarithm of the variance between plots of a given size was linearly related to the logarithm of the size of the plot. In the presentpaper we consider only the relationship between size and variability. The objects of the paper are, firstly, to show efficient estimates of the constants in this relationship may be determined, and secondly, to illustrate a general method of determining efficient linear estimates when the data are, as in the present instance, correlated and of unequal variability. aCulturas1 aWILLIAMS, E. J. tBiometrics, p.207-222, 1958.