Chat Isn’t One Thing
Synchronous chat (live agent) differs from asynchronous chat (SMS, email). Voice differs from both. Multimodal (chat with image support) differs from pure text. Design per channel.
Turn-Taking Design
Make turn boundaries clear. Indicate thinking states. Handle interruptions gracefully in voice. Progress indicators in async flows. The user should always know what the system is doing.
Error Recovery
When the AI fails, make recovery obvious. ‘I didn’t understand; could you rephrase?’ over a cryptic error. Offer alternatives — human escalation, reformulated input, related capability.
Accessibility
Voice interfaces must work for users with speech differences. Chat must work with screen readers. Video must have captions. Accessibility isn’t optional; it’s design. 2026 EU AI Act underlines this.