Effective Voice Menus 
One of the most common dialog designs in IVR and speech recognition applications is the menu. You've heard it, you've built it, it's everywhere:
"Press 1 for Sales, press 2 for Marketing or press 3 to leave a message."
As a design device, menus give the flexibility of presenting choices to the caller in a directed manner. They are simple to formulate and they are robust. But there's more to menus than meets the eye. By following some simple rules, we can increase caller satisfaction and improve the overall quality of our Voice Sites.
With speech recognition systems such as Angel, developers have a wider array of choices than simply DTMF (Dual Tone Multi Frequency -- essentially keypad presses) menus. With voice, natural sounding and engaging menus can be built. But using voice menus is not without challenges, and a direct translation from DTMF to voice ("Press or say 1 ...") can cause more harm than good.
Thankfully, this is a well understood problem today, with a growing body of knowledge that addresses these issues.
Bruce Balentine, VUI design maestro, shares some great advice in his book "How to Build a Speech Recognition Application":
- Avoid the For ... Say or To ... Say Construct.
- Avoid: To find out your balance, say "balance", to request a transfer, say "transfer"
- Use: You can say "balance", "request a transfer" or ...
- Expressions like find out or request, confuse callers, who will have a hard time remembering the right wording for the available commands.
- With Angel's advanced barge-in capabilities, a short list will further increase success rates, allowing callers to say the right command as soon as they hear it.
- Use Landmarks for Navigational Feedback
Examples: - Angel: You can say "balance", "request a transfer" or "operator"
- Caller: balance, please
- Angel: Account Balance Your checking account, ending in 333, has a balance of ...
- Balantine says: 'A landmark is a ... cue that marks a specific location within the dialogue'. Landmarks help callers navigate your Voice Site by reminding them where they are. Some useful landmark candidates are menu names ('Main Menu'), application-specific objects ('Calendar') and navigational marks ('First Message').
- If the User is an expert, let him go first. Examples:
- 'Main Menu (pause, or beep, or soundmark) ... You can say Balance, Request a Transfer, or Operator'
- By providing a small 'slot' for the expert caller to speak, rapid navigation of the menu structure is enabled. The landmark acts as a reminder of the available commands for callers who know what they're looking for.
- Present menu choices when the caller doesn't speak or when what was said is out of context. Avoid:
- Angel: Main Menu (pause, or beep, or soundmark) ...
- Caller: (doesn't speak)
- Angel: Please make your selection
- Use:
- Angel: Main Menu (pause, or beep, or soundmark) ...
- Caller: (doesn't speak)
- Angel: You can say Balance, Request a transfer, or Operator
- When a caller doesn't speak, it's an indication that they are confused (don't remember their choices), or lost (don't remember the location in the Voice Site), or are busy with another activity away from the phone. Sometimes when designing these escalating 'No Speech' and 'No Match' prompts, we spend too much time prodding the user to repeat what they said, or apologizing for not understanding or not hearing them. Better results are achieved when these steps are skipped and immediate guidance is given.
There are lots of ways to make application menus work better. The good part is that Angel.com allows for easy experimentation with its rapid prototyping approach. Try different things with a select number of callers and soon an understanding of what works for your situation will develop.
And remember, we're always here to help! Send your VUI questions to aparicio@angel.com
