Conversational Design Principles
- Be brief. Voice responses longer than 15 seconds lose users.
- Be relevant. Answer the question first, then offer options.
- Be transparent. Tell users what you can and can't do.
- Provide escape hatches. "You can say 'stop' at any time."
- Confirm destructive actions. "Delete all reminders. Are you sure?"
Prompt Design
- Open prompts: "What would you like to do?" (broad, intimidating)
- Closed prompts: "Would you like to order the same as last time?" (specific, easy)
- Guided prompts: "You can say 'reorder,' 'browse menu,' or 'check order.'" (helps discovery)
Error Handling
- "I didn't catch that. Could you say it again?"
- After 2 failures: "Let me show you some options instead."
- After 3 failures: transfer to screen-based UI or human.
Multimodal
- Voice + screen: show what you're saying.
- Allow switching between voice and touch mid-task.
- Visual confirmation of voice commands.