ABSTRACT
A semiquantitative spectral classification scheme for middle-type supergiant stars is presented which is wholly dependent on data in the near infrared. The method involves the measurement of central depths as indicators of the strengths of the Paschen hydrogen lines 12 through 16, the Ca II infrared triplet and the 7774-A blend of O I, and was tested on slit spectrograms of previously classified stars of spectral types B8 through G2. Results for the 142 stars considered are found to agree well with the MK spectral types determined previously, particularly in spectral types A5 through G0 and luminosity classes Ia through II.