Intelligent tutoring systems need a model of learning goals for the personalization of educational content, tailoring of the learning path, progress monitoring, and adaptive feedback. This article presents such a model and corresponding interaction designs for the coaches and learners (respectively, a monitor-andcontrol dashboard and mobile app with supportive communications trough a virtual agent), all deployed and tested in a system for child diabetes self-management training. We developed a domainindependent upper ontology to structure learning goals and related concepts (such as achievements and tasks) and a domain ontology that specifies the knowledge base (for, in our case, diabetes selfmanagement training). With this approach, we relate knowledge elements (e.g., skill) to educational tasks and to learners' knowledge development (e.g., achievements). The ontology was implemented in a multimodal tutoring system consisting of mobile educative games, a health diary, an embodied conversational agent (ECA), and a web application for authoring and monitoring. We show that our model provides a coherent and concise foundation for: 1) the formalization of learning in the diabetes self-management domain, but also for other domains such as mathematics; 2) personal goal setting and thereby personalization of the educational process including ECA's guidance; and 3) creating awareness of progress on the personal educational path. We found that a motivational tutoring system requires a rich set of learning activities and accompanying materials of which a subset is offered to the learner based on personal relevance. The implemented model proved to accommodate the personal agent-guided learning paths of children with diabetes, under different treatments from hospitals in Italy and the Netherlands.