A systematic analysis of low-energy anisotropy data derived from nonimpulsive energetic (0.3--0.5 MeV) proton events has been carried out with the APL/JHU detectors on board the IMP 7 and 8 spacecraft during 1972--1975. After reducing to a minimum any magnetospheric influence by applying various selection criteria, 1289 hourly anisotropy averages survived for which we also had simultaneous hourly averaged solar wind and magnetic field observations. These anisotropy vectors were resolved into components parallel and perpendicular to the measured magnetic field. Analysis of the resulting anisotropy distributions leads directly to the following conclusions: (1) The average perpendicular anisotropy component is nearly entirely accounted for in terms of the E¿B drift, and hence interplanetary transverse diffusion is negligible at these energies. (2) Application of diffusion-convection theory to our data yields an estimate of a representative value for the ratio of mean free paths transverse and parallel to B which is consistent with zero but bounded above, i.e., 0?&lgr;1/&lgr;∥<0.05. (3) The parallel anisotropy component averages nearly to zero over many events, consistent with virtually no net particle streaming along the field line in nonimpulsive particle events at 1 AU. Therefore the net event-averaged anisotropy of 0.3-- to 0.5-MeV protons observed by spacecraft located at 1 AU is outward away from the sun in a direction approximately perpendicular to the nominal magnetic field, implying that this population of protons is, on the average, being removed from the vicinity of 1 AU simply by 'cross-field convection,' i,e., the E¿B drift.