User modelling for motivational systems : the affective and the rational routes to persuasion

The idea that a computer system could be used to motivate people to perform a certain task on the basis of a user model is certainly not novel. As early as the 80s, intelligent tutoring systems would encourage students to learn by means of tailored feedback and hints [24], and in the 90s patient education systems would attempt to address the problem of compliance to a medical regimen by means of information and personalised advice [1] or would encourage people to adopt healthier lifestyles [19]. It is however only recently that a number of, seemingly non correlated, extensive research efforts, from various perspectives, have started to focus on a more complex cognitive model of rational and extra-rational features, involving emotions, persuasion, motivation and argumentation. We can distinguish three parallel strands of research that have become prominent.