An additivity model of the apolar solute‐solvent parameter log(L16) was verified using sets of 939 nonaromatic and 1075 aromatic compounds. Unbiased distributions of errors and of the contribution significance level were statistically tested. An analysis of the CH2group contribution in 34 homologous series indicates that the differences among the homologous series are statistically insignificant and related to interactional contributions rather than to the nature of the CH2group. ©1996 American Institute of Physics and American Chemical Society.