The Stoner‐Wohlfarth model is used to calculate the remanence of a randomly‐oriented assembly of singledomain particles when the applied field changes in direction. The cases considered are (1) fields applied successively in directions differing by multiples of ½&pgr; and (2) fields rotated through multiples of ½&pgr;. Some consideration is also given to the anhysteretic remanence when the unidirectional and alternating fields are orthogonal. Experimental results obtained on disks of &ggr;Fe2O3recording tape are found to be in reasonably good qualitative agreement with the calculations.