Conversational interface

When is an interface a "conversational" one? It seems that "talking" with your interface is becoming the trending solution for optimising services. The primary input method has always been typing answers in a box, but filling in a form is seldom a pleasurable experience. Mostly this is process-driven input, since the answers need to be a in a specific format. It's kind of similar when you order food at a drive trough restaurant. The respons needs to be in the correct sequence, otherwise the cashier can't process your order. Because having a conversation is of course a prefamuch more personal might be the her where talking is the preferred way. Star Trek was, like always is way ahead on these ideas. One very functional application of artificial intelligence is that the system processes the speak into something understandable. Is the criteria that you can input tekst by voice. Is the focus on the feeling, or simulation of a person. How does the system handle different formatted input.