Embodied Conversational Agent

A computer-generated animated character designed to interact with human users using multiple simultaneous communication channels — typically speech, eye gaze, facial expression, head and body posture, and hand gestures. ECAs are used in tutoring systems, customer-service agents, virtual humans for training, and research on multimodal dialogue. In accessibility work, ECA techniques underpin signing avatars that perform sign language, speech-output agents that assist users with cognitive or literacy support, and social-skills training systems for autistic users. ECAs raise specific accessibility concerns of their own — they can be unreadable to blind users if their animation is not paired with speech or text alternatives, and they have been criticised by the Deaf community when deployed as substitutes for human interpreters.