A method for managing interactive dialog between a machine and a user is claimed. In one embodiment, an interaction between the machine and the user is managed by determining at least one likelihood value which is dependent upon a possible speech onset of the user. In another embodiment, the likelihood value can be dependent a model of a desire of the user for specific items, a model of an attention of the user to specific items, or a model of turn-taking cues. Further, the likelihood value can be utilized in a voice activity system.