  Observing extrasolar planetary transits is one of the only ways that we may
infer the masses and radii of planets outside the Solar System. As such, the
detections made by photometric transit surveys are one of the only foreseeable
ways that the areas of planetary interiors, system dynamics, migration, and
formation will acquire more data. Predicting the yields of these surveys
therefore serves as a useful statistical tool. Predictions allows us to check
the efficiency of transit surveys (``are we detecting all that we should?'')
and to test our understanding of the relevant astrophysics (``what parameters
affect predictions?''). Furthermore, just the raw numbers of how many planets
will be detected by a survey can be interesting in its own right. Here, we look
at two different approaches to modeling predictions (forward and backward), and
examine three different transit surveys (TrES, XO, and Kepler). In all cases,
making predictions provides valuable insight into both extrasolar planets and
the surveys themselves, but this must be tempered by an appreciation of the
uncertainties in the statistical cut-offs used by the transit surveys.
