Density and birefringence studies are carried out on two lower homologues of alkoxybenzylidene alkoxyanilines viz., N-(p-n-ethoxy and propoxy benzylidene)-p-n-pentyloxy anilines, 2O.O5 and 3O.O5. Both the compounds exhibit high temperature nematic phase only with varied thermal ranges suitable for the study of birefringence. The refractive indices are measured using an indigenously developed spectrometer coupled with a small angled prism. The density measurements are carried out for the evaluation of molecular polarizabilities based on the two well known isotropic (Vuks) and anisotropic (Neugebauer) models. The molecular anisotropy is obtained using Lippincott delta-function model. Further, the molecular anisotropy was obtained using Haller's extrapolation technique. The orientation order parameter is evaluated (using different techniques developed) in the nematic phase and compared with one another and the results are discussed in the light of the literature data available on other liquid crystal compounds.