The expanding/contracting polar cap (ECPC) paradigm, or the time-dependent Dungy cycle, provides a theoretical framework for understanding solar wind-magnetosphere-ionosphere coupling. The ECPC describes the relationship between magnetopause reconnection and substorm growth phase, magnetotail reconnection and substorm expansion phase, associated changes in auroral morphology, and ionospheric convective motions. Despite the many successes of the model, there has yet to be a rigorous test of the predictions made regarding ionospheric convection, which remains a final hurdle for the validation of the ECPC. In this study we undertake a comparison of ionospheric convection, as measured by ion driftmeters on board DMSP (Defense Meteorological Satellite Program) satellites, with motions predicted by a theoretical model (Milan, 2013) coupled to measurements of changes in the size of the polar cap made using global auroral imagery from the IMAGE FUV (Imager for Magnetopause to Aurora Global Exploration Far Ultraviolet) instrument. The results are discussed in the context of our understanding of magnetic reconnection at the magnetopause and in the magnetotail.