Interacting with computers is ever changing; the activities computers are used for, thedomains they are used in, the people who use them, and the way that they are usedhave been constantly evolving. But over the past few years an additional dimensionhas been added to this interaction, which considers the utility and effectiveness ofincorporating emotion into the interface. Over ten years ago, Rosalind Picard coinedthe phrase “affective computing” for computing that relates to, arises from, or deliberatelyinfluences emotion or other affective phenomena1. Since then, numerous researchersall over the world have devoted themselves to studying the role affect andemotion play in our interactions with technology. The affective computing communityis growing rapidly. A number of workshops, symposia, and even conferences makeemotion in HCI their subject. This book actually developed out of some of thoseevents. When Springer approached us to compile a book on the subject, we were justorganizing the third workshop on emotion in HCI at the British HCI Group’s annualconference, held in the UK. While the workshop had numerous contributions from thetraditionally very active British and European community, we also received contributionsfrom overseas.