1. A method of managing a dialog turn between a user and a spoken dialog system, the method comprising: storing weights assigned to varying dialog turn information based on statistical information in a weight database; generating first dialog turn information using dialog information analyzed from a speech uttered by the user; generating second dialog turn information using facial expression information analyzed from a face image of the user; synthesizing the first dialog turn information and the second dialog turn information and outputting the synthesized dialog turn information when the first dialog turn information is different than the second dialog turn information, and outputting one selected from the first dialog turn information and the second dialog turn information when the first dialog turn information is identical to the second dialog turn information; searching the weight database for weights corresponding to the synthesized dialog turn information, assigning a positive weight to each of the first and second dialog turn information based on the synthesized dialog turn information and selecting whichever one of the first and second dialog turn information has a greater positive weight; and determining a final dialog turn using the selected one dialog turn information, information on a status of the spoken dialog system, information on whether the user speech is input, and information on a no-answer time of the user, for controlling a dialog between the user and the spoken dialog system.