Iσ‐Index, a measure of dispersion of individuals

Conclusion and summary As the I σ ‐index is neither affected by the mean per sample unit except for regular distribution nor standing on the assumption of any definite type of contagious distribution, it may have the most wide range of application among the ones hitherto deviced for measuring the dispersion of individuals in a population. The relations of the I σ ‐index to , k of negative binomial distribution and N of binomial distribution as well as the new dispersion index, I B , given in this paper may serve, if necessary, for the analysis of data in the ecological works.