ABSTRACT
A spoken dialog system is a computer system able to interact with humans using speech and is increasingly shaping our daily life. Examples include Apple Siri, Google Now, Microsoft Cortana and other numerous dialog systems. The dialog system can be divided into two types: chat-type dialog systems and task-oriented dialog systems. People regard chat-type dialog systems as a virtual person with whom they can speak. During the conversation, the content of the conversation has usually less strict grammatical structure and unconstrained spontaneous language. For task-oriented dialog systems, people regard the system as an interface to complete the task they want to accomplish by using speech commands to fill the dialog slots. In addition, the content of a task-oriented dialog usually has stricter grammar and constrained commands. Table 34.1 summarizes the distinction between chat-type dialog systems and task-oriented dialog systems (Skantze, 2007).
