Digital lifestyle coaches on the move

Persuasive technology refers to research after and development of instruments that can support people, society, institutions or governments to persuade other people of a particular opinion or to behave in a particular way. A digital lifestyle coach is a behavior change support system, a special type of persuasive technology. Rhetoric and social psychology are basic sciences that inform technologists about the principles, strategies and tactics of persuasive communication and about the factors that determine the successfulness of the use of persuasive technologies. We present the main requirements for these technologies and show how they motivate the use of information and communication technology, services, sensors and new mobile hardware devices. Digital coaches play the role of a human coach and clients experience the system as a social actor. This motivates to present the system on the user interface as a graphical virtual human that addresses her messages verbally to the client. Research has shown that this may have a positive effect on the successfulness of the system. As an illustration we present a digital coach that is developed to support diabetes patients to adhere to a more healthy lifestyle. We present results of a comparative experiment to see if the use of a virtual human improves the eectiveness of the digital coach compared to presenting the message by a simple text message.