The task. "KANT" (Kritical Argument Negotiated Tutoring system) was an ITS designed for teaching analysis of musical phrase structures in tonal melodies [Baker 89c, 92b]. The domain model was based on a (chart) parser that was able to take tonal melodies as input (via a MIDI keyboard) and produce a set of possible parses for the position of phrase and sub-phrase boundaries as output [Baker 89a, 89b]. Drawing on Lerhahl and Jackendoff's "Generative Theory of Tonal Music [83], we showed that multiple knowledge sources interact simultaneously to determine musical structures - for example, rhythmic differences, micro-pauses, intervallic structures, contrasts in dynamics, and, most importantly, harmonic structures. The knowledge to be taught embodied in the system therefore consisted of sets of beliefs concerning musical structures, that were justified in terms of these different knowledge sources. The system also contained a semantic network, with "canned text" explanations for the concepts embodied in beliefs and their justifications, as well as for controlling dialogue focus shifts.
The agents. The two agents involved were 'system = teacher' and 'human user = novice'. Given that the domain to be taught consisted of justified belief sets, a non-directive or negotiative tutorial interaction style was therefore deemed to be appropriate.
