  We examine the decay rate of the particle decay $B^0 \rightarrow D^- \ell^+
\nu_{\ell}$ using data collected from the Belle Collaboration. We studied three
parameterizations of the form factor which describe the differential decay
rate, the Caprini, Lellouch, and Neubert (CLN) parametrization, the Boyd,
Grinstein, and Lebed (BGL) parametrization, and the Bourrely, Caprini, and
Lellouch (BCL) parameterization. The form factor is a function of the hadronic
recoil variable $w$, and each parameterization contains unique free parameters
which are the focus of this work. We test the extrapolations of the form factor
by fitting many different subsets of the low $w$ data and then compare the
prediction of the fit to the high $w$ data using a $\chi^2$-metric. By only
fitting the low $w$ data we are able to examine the stability of extrapolations
which will be informative for lattice simulations.
