1. A computer-implemented method comprising facilitating successive conversations between a user of a device and a non-human companion portrayed on the device, to develop a relationship between the user and the non-human companion over a time period that spans the successive conversations, the relationship being developed between the user and the non-human companion to cause a change in a state of the user over the time period, the facilitating of each of the successive conversations comprising: presenting to the user a segment of speech of the non-human companion, detecting a segment of speech of the user, the user's segment of speech and the segment of speech presented to the user comprising a portion of the conversation, receiving at the device, from an intelligent agent, information about a next segment of speech to be presented to the user, as determined by the intelligent agent based on intelligent processes applied to the segment of speech of the user and the change in state to be caused.