The Structure of User-Adviser Dialogues: Is there Method in their Madness?

Novice users engaged in task-oriented dialogues with an adviser to learn how to use an unfamiliar statistical package. The users', task was analyzed and a task structure was derived. The task structure was used to segment the dialogue into subdialogues associated with the subtasks of the overall task. The representation of the dialogue structure into a hierarchy of subdialogues, partly corresponding to the task structure, was validated by three converging analyses. First, the distribution of non-pronominal noun phrases and the distribution of pronominal noun phrases exhibited a pattern consistent with the derived dialogue structure. Non-pronominal noun phrases occurred more frequently at the beginning of subdialogues than later, as can be expected since one of their functions is to indicate topic shifts. On the other hand, pronominal noun phrases occurred less frequently in the first sentence of the subdialogues than in the following sentences of the subdialogues, as can be expected since they are used to indicate topic continuity. Second, the distributions of the antecedents of pronominal noun phrases and of non-pronominal noun phrases showed a pattern consistent with the derived dialogue structure. FinMly, distinctive clue words and phrases were found reliably at the boundaries of subdialogues with different