These are some of the things I picked up for designing a very good voice experience. These are guidelines and not rules and definitely not the whole picture. I’d treat this as a simple guide to evaluate.
- Understand your target audience before starting any design work.
- Use the brand’s persona for creating and playing prompts.
- Use conversational language rather than treating the system as “information collector”.
- Try not to use “Please” on every single line.
- Try not to use “Sorry” too much.
- Understand your users’ mental model and cognitive limitations when presenting information. For example, native English speakers often place new information at or near the end of the sentence, and this is where they often expect to retrieve it.
- Use cohesion devices such as pronouns, discourse markers, pointer words, etc.
- Remove words and phrases that can be supplied by context.