Temperature classes based on photometric measurements of the 7100 Å band of TiO are compared with published spectroscopic classifications by various investigators. Dwarfs, giants, and supergiants are treated separately. The photometric types are in excellent agreement with types given by P. C. Boeshaar for M dwarfs and by P. C. Keenan and Y. Yamashita for M giants. In all other cases the scatter is larger. The usefulness of the types given by various authors for dwarfs and giants is tested by examining their correlation with color temperature determined by narrow-band photometry.