A method is described for estimating the shape factor, the ratio of the maximum and minimum projected diameters, of a fiber from measurements made on a longitudinal view. The method assumes that the measured diameters have a uniform distribution, an assumption which seems justified for cotton fibers. An estimator of the shape factor is given; a confidence interval for the shape factor is derived; and a sampling plan together with formulae for determining an adequate sample size is presented.
Confidence interval estimation for pooled-sample biomonitoring from a complex survey design
