3. A computer-implemented interactive voice response system for dynamically modifying automated machine playback of messages in a manner that approximates actual human dialog by varying key variables associated with an application domain, comprising: a database containing a plurality of synonyms for the key variables associated with the application domain and predetermined rules for selecting a synonym for a key variable based on a context of a message to be generated; and a processor that accesses the database, wherein the processor is programmed to: receive a user request for information; retrieve data based on the information requested; generate a message responsive the user request for conveying the information to the user; dynamically modify the message by altering intonation and selecting an appropriate synonym for each key variable of the message from the database, wherein the altering and the selecting are both based on a context of the information to be presented, wherein the context is related to the application domain and defines situations where different key variables can be selected based on certain determination criteria; and play back the modified message to the user; wherein the intonation includes at least one of a volume, a speed, and a pitch, wherein the key variables include at least one of key verbs and adverbs, and wherein the key variables are selected among a finite set of synonyms in the database based on the context of the information to be presented to the user.
4. The system of claim 3 , wherein the finite set of synonyms vary along a continuum from a standard outcome to a highly unlikely outcome or to an extreme outcome of an event.