SEQUENTIAL DEPENDENCIES IN COMPUTER-AIDED CONVERSATION

The structure of computer-aided conversations obtained with a prototyp e system designed for use by physically handicapped, non-speaking peop le was investigated. The conversational aid requires speech acts suita ble for use in a conversation on a fairly broad topic (e.g. holidays) to be generated by the computer user ahead of time. The potential spee ch acts are then organized to facilitate rapid selection of appropriat e items for output via a voice synthesizer during subsequent conversat ions. Lag-sequential analyses were used to identify sequential depende ncies between the speech acts of computer-aided and unaided participan ts. The obtained sequential dependencies were broadly similar to those found for normal conversations on the same topic. Where differences e xisted, they were readily explicable in terms of conversational goals appropriate to the different modes of discourse. The results of the di scourse analyses were interpreted as evidence for the coherence of the computer-aided dialogues at the level of speech acts. It was suggeste d that the sequential dependencies found between speech acts, and betw een categories within alternative taxonomies, might be used to reduce switching pause times in computer-aided conversations by building them into the system as predictions.