A dialogue moderator for program specification dialogues in the PSI system
Louis I. Steinberg · 1980
This thesis describes work that has been done with the aim of making it easier to specify a program to a computer. A system has been programmed to engage in a topic initiative with the user--that is, a dialogue where both parties can influence the order in which topics are covered. In addition to describing a specific system called DM, a module of the PSI Program Synthesis System, we will discuss the general ideas of initiative and structure in dialogues and will establish connections between these ideas and those of expectations and speech acts. The main emphasis will be on viewing a dialogue as a means by which the participants achieve a goal. In discussing how a system can handle mixed initiative dialogue we will consider the problems of choosing one question to ask (out of all those logically possible at a given time) and handling (discussion during the dialogue about the structure of the dialogue). The PSI System, of which the Dialogue Moderator (DM) described here is a part, engages in a mixed initiative dialogue with a user who is specifying a program. DM is the module of PSI responsibile for following and guiding the flow of topics in this dialogue and for helping discuss this topic flow with the user. After describing the reasons for having a separate dialogue moderator module we will discuss the mechanisms that DM uses for choosing which question to ask, how these mechanisms have been tested, and how mechanisms for meta-dialogue might be added to them. It will be seen that if a system is to engage in mixed topic initiative dialogue, that is, if the system's choice of topic is to be sensitive to what the user says, then it is advantageous to have a separate dialogue moderator. DM chooses a question to ask by a process of rule-directed search on a network representing the structure of the dialogue. It will be seen that this mechanism is effective and flexible. It also appears reasonable that mechanisms for handling meta-dialogue might be integrated with this mechanism for question choice.