“…In theory, the ultimate solution for this would be a full naturallanguage interface with an intelligent agent in the background that has both the full domain knowledge as well as the required conversational knowledge, i.e., how to lead dialogs or react on specific situations. Existing work in that direction (e.g., [22], [23]) shows the general applicability of such natural-language style approaches in e-commerce settings, but still there are open problems. Beside the unresolved problem of understanding general user utterances beside from domain knowledge, today's systems still require huge knowledge acquisition and dialog modeling efforts to reach an acceptable dialog quality.…”