Range as a measure of dispersion in forest sampling

The assumption of randomness, underlying the use of range as an estimator of the standard deviation in a normal parent population, was deliberately violated in order to assess how restrictive is this assumption in sampling tree diameters and heights. In only four, out of 34 non-random samples, were the estimates of population standard deviation using range significantly lower than the corresponding root-mean-square estimates. These underestimates were reduced by randomizing the collected data.