US Patent 9472193 Speech dialogue control method

A cloud server extracts voiceprint data from voice data of a user, and distinguishes the user. The cloud server identifies a task which the user instructs, from the voice data of the user. If contexts required to execute the task have not been amassed, the cloud server registers the distinguished user as a task owner, and notifies the user with a reply sentence to cause the user to speak the required context. If the voiceprint data of the voice data which the user has uttered matches the voiceprint data of the user A, and all required contexts are amassed, the cloud server causes a device to execute the task.