Most attempts to incorporate non-literal aspects of communication into natural language interlaces have attempted to model human performance as closely as possible. The typical mode of communication in such an interface, in which system and user type alternately on a single scroll of pager (or scrolled display screen), has been used as an analogy to normal spoken human conversation in Wlllcll contmunicallon takes place over a similar half-duplex channel, . a channel that only one party at a time can use witllout danger of confusion. .
