Method and apparatus for providing interactive services with multiple interfaces

Abstract

Interactive services are provided by employing a modular approach to implementing interactive services with multiple interfaces. Such an approach facilitates supporting natural language understanding interaction with users through use of interfaces that allow at least different ordering of inputs, and/or incomplete information, and/or correction of information, and/or the return of control to prior points in the service. This is realized, in an embodiment of the invention, by employing a single interactive service logic that uses “reactive constraint graphs”, i.e., a form of event-driven graph, in which nodes contain a set of constraints on events. Specifically, control progresses from a node to a derivative node, i.e., “child”, only when all the constraints in the set on the node have been satisfied. A single set of constraints implicitly supports a significant number of the possible different orderings of inputs. Incomplete information is supported because the constraints in the set are evaluated as soon as possible. Correction of information is supported because information in the constraint set is updated upon receipt of new information. Indeed, use of the reactive constraint graphs allows nodes to be labeled, and allows control to revert to a prior node, i.e., ancestor, hence allowing the user to go back to prior points in the service. New inputs can be added to the constraint sets with a complexity polynomial of the order of the input set.