Recently, extensive data sets have been acquired from charged-particle detectors on low-altitude satellites pertinent to the study of the low-latitude boundary of the aurora, including both case studies and statistical treatments. The low-latitude auroral boundary can be thought of as the low-altitude manifestation of convection boundaries for magnetospheric particles of moderate energy, although the detailed shape of the boundary might be modified locally by spatial variations or temporal modulation of precipitation rates. Several attempts have been made to compare observed equatorial and low-altitude boundaries with theoretical representations, with varying degrees of success. Here, the results of statistical analysis and case studies of the auroral boundary using precipitating particle data acquired by the National Oceanic and Atmospheric Administration spacecraft are presented. The ability of standard convection models to account for the observed boundary characteristics is discussed, with emphasis on the roles of convection strength and time dependence. It is demonstrated that within reasonable parameter limits, steady state convection patterns for moderate energy electrons generally fail to account for certain observed characteristics of boundary shapes. Further, it is demonstrated that time-dependent transitions between various levels of activity can lead to characteristic boundary shapes that are quite dissimilar to steady state solutions and to some extent can provide a resolution between observed and computed boundary shapes for time scales pertinent to magnetospheric activity. The length of time after the onset of enhanced convection is found to be at least as important as the instantaneous level of activity as an ordering parameter for the shape of the low-latitude auroral boundary. ¿ Americal Geophysical Union 1987