Despite a long history of both experimental and theoretical investigations, the microscopic picture of ions at the aqueous liquid-vapor interface remains controversial, particularly with respect to ion partitioning between the bulk fluid and the surface. Although thermodynamics predicts that the interface should be depleted of ions based on the increase in surface tension, many recent studies demonstrate that certain anions, such as Cl- and I-, seem instead to prefer a surface location. Reasons for this apparent preference remain unclear, but the surface enhancement is often attributed to increasing polarizability of these ions. While the radius of the ions also increases with the polarizability, little has been learned about separating the size and polarizability effects. In an effort to further explore the driving force of the observed partitioning, we perform Monte Carlo simulations to investigate the interface for neat water and water-ion mixtures. We consider two types of ion mixtures: one with ions of varying size, but all having the same fixed charge, and the other with ions of varying polarizability, but all having the same size. By comparing the effects of both ion size and polarizability, we are better able to understand what role these attributes play in ion partitioning.