21. The system of claim 15 wherein the at least one processor is further programmed to: provide a session document for the presentation, wherein the session document includes a session grammar and a session structured document; select from the session structured document a classified structural element in dependence upon user classifications of a user participant in the presentation; and present the selected structural element to the user participant.
22. The system of claim 21 wherein the at least one processor is further programmed to select a classified structural element having an associated classification identifier that corresponds to the user classification.