The9thInternationalConferenceonIntelligentTutoringSystems(ITS2008)was heldJune 23-27,2008inMontreal. Thisyearwecelebratedthe 20thanniversary ofthe conferencefounded in 1988in Montreal. We havehadbiennial conferences for most of the past 10 years around the world, including in Brazil, Taiwan, France, Canada, and the USA. These ITS conferences provide a forum for the interchange of ideas in all areas of computer science and human learning, a unique environment to exchange ideas and support new developments relevant for the future. The 2008 conference was a symbolic milestone that enabled us to look back at what has been achieved and what is currently being done, in order to face the challenges of tomorrow. Much has changed in the last 20 years in terms of hardware, software, p- grammers, and education stakeholders. Technology is now networked, pervasive, and availableanyplace and anytime. The potential exists to provide customized, ubiquitous guidance andinstruction. However, much has remainedthe same and the need is just as great to model the learner, teaching strategies and domain knowledge. This year we saw an increase in research into student a?ect (mo- vation, boredom, and frustration), speci?cally attempts to detect student a?ect, while feedback studies consideredwhich responses to provide given both student cognition and a?ect. Studies also looked at the impact on learning of positive feedbackandpolitenessinfeedback. Newresearchwasseenindataminingbased on larger studies that use data from real students to diagnose e?ective learning and teaching. So much interest has been generated in this area that the ?rst International Conference on Educational Data Mining was co-located with ITS 200