Two approaches for improving the method of extracting thin-film optical parameters from spectrophotometer measurements, developed by Case, have been presented: (1) The same unknown thin film was evoporated on two different substrates and the measured reflectances R of the two films at one wavelength were then used for determining the parameters; (2) The unknown thin film was evoporated on one Substrate and its measured reflectances E at different wavelengths were then used for determining the parameters. (2) The unknown, thin film was evoporated on one Substrate and its measured reflectances R at different wavelengths were then used for determining the parameters. These two approaches are not only easy, but also provide higher accuracy.