My Science Tutor (MyST) is an intelligent tutoring system designed to improve science learning by elementary school students through conversational dialogs with a virtual science tutor in an interactive multimedia environment. Marni, a lifelike 3-D character, attempts to elicit self-expression from students, process their spoken explanations to assess understanding, and scaffold learning by asking open-ended questions accompanied by illustrations, animations or interactive simulations. MyST uses automatic speech recognition, natural language processing and dialog modeling technologies to interpret student responses and manage the dialog.

Index Terms: spoken dialog, virtual tutors