title: The variance of the index (R) of aggregation of Clark and Evans.
abstract: The exact formula for the variance of the Index (R) of aggregation of Clark and Evans is derived. Due to the fact that R is a dimensionless number, its variance is independent of population density, being only a function of the sample size and so can be manipulated.
authors.affiliation: UNESP-Depto de Ecologia, 13.500, Rio Claro, SP, Brazil.
authors.forename: Miguel
authors.initials: M
authors.lastname: Petrere