  We explore the extent to which Spitzer IRS spectra taken at low spectral
resolution can be used in quantitative studies of organic molecular emission
from disks surrounding low mass young stars. We use Spitzer IRS spectra taken
in both the high and low resolution modules for the same sources to investigate
whether it is possible to define line indices that can measure trends in the
strength of the molecular features in low resolution data. We find that trends
in HCN emission strength seen in the high resolution data can be recovered in
low resolution data. In examining the factors that influence the HCN emission
strength, we find that the low resolution HCN flux is modestly correlated with
stellar accretion rate and X-ray luminosity. Correlations of this kind are
perhaps expected based on recent observational and theoretical studies of inner
disk atmospheres. Our results demonstrate the potential of using the large
number of low resolution disk spectra that reside in the Spitzer archive to
study the factors that influence the strength of molecular emission from disks.
Such studies would complement results for the much smaller number of
circumstellar disks that have been observed at high resolution with IRS.
