Our mission is to develop the computational techniques that will enable the design, implementation, and evaluation of "relational" robots, in order to encourage social, emotional, and cognitive growth in children, including those with social or cognitive deficits. Funding for the project comes from the NSF Expeditions in Computing program. This expedition has the potential to substantially impact the effectiveness of education and healthcare, and to enhance the lives of children and other groups that require specialized support and intervention. In particular, the MIT effort is focusing on developing second-language learning companions for pre-school aged children, ultimately for ESL (English as a Second Language).