This survey reveals that the five functioning automatic association programs existing today in the world, even though they were developed separately in independent institutions, all operate according to the same general schema. Different algorithms and strategies do appear in the event refinement process, and seem to use as much of the attributes of the data as possible to exclude misassociations and false alarms. Recommendations are made for the SDAC AA and ADAPS to use as many of these algorithms as can be supported by the data.