Data from an accelerometer package are used to estimate the rates at which interaction events occur between adjacent ice floes in the marginal ice zone. Observations suggest that the events are principally the result of a modified collision process, where brash ice partially filling the gap between two floes acts as an intermediary in the transfer of momentum from one to the other. A model is presented from which the rate at which these interactions occur can be predicted. Comparison of the rates estimated from the data with those predicted by the model shows there to be some agreement, although there is considerable room for improvement. The predicted event rate depends strongly on the ratio of the root-mean-square wave height to the ammount of open water between pairs of flows. The form of this dependence offers an explanation for grouping of events, a feature that may be readily observed in many extracts of data. ¿ American Geophysical Union 1992