A quantitative treatment of the specular reflection spectra obtained from the surface of uniaxially drawn poly(ethylene terephthalate) samples has been performed. A procedure for correcting for the effect of surface irregularities is presented, and an overall orientation function based on the orientation and content of trans conformers is calculated. The results are correlated with mechanical modulus and crystallinity values. In addition, an unconventional dichroic ratio parameter based on a combination of two major bands is proposed. Results obtained from the Kramers-Kronig analysis and directly from the reflection spectra are discussed. Both are compared with the overall orientation function obtained before.