Interactive learning environments have been built to support various audiences from preschool to university students. However, it is not yet known how to bring the great promise of tutorial dialogue systems, which engage students in rich natural language, to bear for young learners such as those in grades K-5. This doctoral consortium paper presents our goal of developing a dialogue system in the form of an interactive spoken dialogue agent with embedded assessment to support K-5 students in learning computer science. It discusses the challenges faced so far and how we plan to solve those challenges to bring individualized dialogue systems technology to young learners.