Hennessy, PippaBenford, SteveBowers, John2017-04-152017-04-151989This paper was first published in the Singapore International Conference on Networks'89, pages 56-61. It describes the COSMOS, AMIGO MIIS+, AMIGO Advanced, and MacAll II models of group communication, and compares them from four key perspectives. The need for an intergrated approach to modelling group working is stated, and features that should be included in any model are identified.enText