  We present the results of a study of selection criteria to identify Type Ia
supernovae photometrically in a simulated mixed sample of Type Ia supernovae
and core collapse supernovae. The simulated sample is a mockup of the expected
results of the Dark Energy Survey. Fits to the MLCS2k2 and SALT2 Type Ia
supernova models are compared and used to help separate the Type Ia supernovae
from the core collapse sample. The Dark Energy Task Force Figure of Merit
(modified to include core collapse supernovae systematics) is used to
discriminate among the various selection criteria. This study of varying
selection cuts for Type Ia supernova candidates is the first to evaluate core
collapse contamination using the Figure of Merit. Different factors that
contribute to the Figure of Merit are detailed. With our analysis methods, both
SALT2 and MLCS2k2 Figures of Merit improve with tighter selection cuts and
higher purities, peaking at 98% purity.
