  Pulsation models are crucial for the interpretation of spectrophotometric and
interferometric observations of Mira variables. Comparing predicted and
observed spectra is one way of establishing the validity of such models. In
this paper, we focus on the models published between 1996 and 1998 by Bessell,
Hofmann, Scholz and Wood. A few new model spectra are added, to improve
available phase coverage. We compare the synthetic spectra with observed low
resolution spectra of optically selected oxygen-rich Miras, over a range of
optical and near-IR wavelengths that encompasses most of the stellar energy
output. We investigate the overall energy distributions, and specific spectral
features in the near-IR wavelength range. The agreement between the observed
and the model-predicted properties is found to be reasonably good. However,
there are discrepancies seen especially in various molecular bands. We find
that different combinations of stellar parameters and pulsation phases often
result in very similar model spectra. Therefore the problem of deriving
parameters of a Mira variable from its spectrum has no unique solution. More
advanced models than presently available, providing even better fits to the
data and covering a wider range of parameters, would be needed to achieve
better discrimination.
