The systems use two methods for finding interpretations for student utterances from the recognized string. First, a Gemini grammar interprets full strings into a complex, structured logical form. A successful Gemini logical form is the preferred interpretation. Next, a robust Nuance NL grammar looks for any interpretable phrases in the utterances which Gemini could not interpret, and uses heuristics to determine the best set of slots and values.
Voice-Enabled DC-Train and SCoT-DC face challenges due to speech recognition errors, disfluent speech, underspecified responses requiring dialogue context for disambiguation, students' varying levels of familiarity and skill at using the preferred military terminology, and the need for coordination with the dialogue manager's strategies for clarification, confirmation and modeling of student uncertainty.