The extent to which various factors contribute to smoothing of the classical small‐angle x‐ray scattering curve in the subsidiary peak region is examined. The effects of finite chromatic and angular resolutions and of shape and size distribution of heterogeneities are determined and discussed. Two methods of obtaining quantitative size data from curves exhibiting asymptotic behavior are discussed. An analysis is presented to show the validity of a method first suggested by Bragg from an empirical evaluation. A new method using an intercept of the extrapolated asymptotic curve is described. The significance of the effective mean heterogeneity dimensions found is discussed. It is shown how correlation with analysis of data for the Guinier region can be used to estimate the spread of heterogeneity size distributions.