<p>A human-computer interface for automatic persuasive dialogue between the interface and a user and a method of operating such an interface. The method comprising presenting a user with an avatar or animated image for conveying information to the user and receiving real time data relating to a personal attribute of the user, so as to modify the visual appearance and/or audio output of the avatar or animated image as a function of the received data relating to a personal attribute of the user. In this way, a more engaging, context sensitive and generally more persuasive automatic dialogue can be generated between the interface and the user.</p>
