Portia: A User-Adapted Persuasion System in the Healthy-Eating Domain

Our eating habits, an essential component of our well-being, are molded by cultural, psychological, and educational factors. These habits solidify over time and are difficult to modify. The information media are masters in employing tricky arguments to persuade people to consume products whose health benefits are doubtful. Attempting to persuade people to adopt more appropriate habits by employing only rational and scientific arguments is probably ineffective; this is one domain in which the mingling of rational and emotional strategies is justified. Of course, the persuader´s arguments must be relevant and strong. This is a subjective judgment, dependent on the persuader´s knowledge about the recipient and the conditions under which the message is expressed. Our prototype persuasion system is the argumentation module of a dialogue system we have developed. After the system acquires information about its users, it informs them about various eating habits´ advantages and disadvantages, provides suggestions in this domain, and tries to persuade them to gradually modify problem behaviors.