The basic commands recommended for any speech application are listed in Table 1; commands shown in bold in the table are the minimum recommended set.
| Global commands | Description |
|---|---|
| Go Back | Backs up to the previous prompt. See Go back. |
| Exit | Exits the application. See Exit. |
| Help | Provides help. See Help. Note: For
language versions other than US English, see the appropriate appendixes.
|
| List Commands | Lists global commands. See List commands. |
| Transfer to Agent | Transfer to a human call center agent. See Transfer to agent. |
| Quiet/Cancel | Stops playback of the current prompt. See Quiet/cancel. Note: For language versions
other than US English, see the appropriate appendixes.
|
| Repeat | Repeats the last prompt. See Repeat. |
| Start Over | Returns to the beginning of the interaction. See Start over. |
| What Can I Say Now | Lists all available commands. |
While the specific implementation of each command depends on the requirements of your application, the general function is described here.
The VoiceXML browser includes simple grammars for Help and Quiet/Cancel. Depending on the grammar style (simple or natural command grammar) of the rest of your application, you might want to add alternative ways of saying these commands by creating additional, auxiliary global grammars.
You should define application-specific commands in grammars that are always active (by specifying them in the application root document with <form scope=“document”>), so users can access them throughout your application. However, there is a trade-off to having a large and robust set of global commands: the potential for misrecognition increases. You should therefore exercise due care when constructing these grammars.
This command lets users back up to the previous prompt.
In any reasonably complex application, users (especially first-time users) might need to explore the interface; while exploring, they might go down an unintended path, and will need a command to back up through the menu (dialog) structure. For example:
|
This command lets users exit the system.
Most users will probably just hang up when they have finished using the system; some users, however, might feel more comfortable if they can say “Exit” and hear the system confirm task completion with a closing message.
When this command is used, the application can also alert the user if a task has been left incomplete, and can prompt the user to complete the task. For example:
|
|
The Exit command also provides an opportunity to engage users in post-usage satisfaction surveys.
It is common to include the word “Goodbye” as a synonym for “Exit.”
This command starts a help mode or causes the application to play the next prompt in a sequence of self-revealing help prompts. See Choosing help mode or self-revealing help for more information.
If your application has a large number of global commands, consider offering users a “List Commands” command.
This command transfers the call to a human call center agent, when available. Typically, the Transfer to Agent grammar should also support the DTMF key 0 as a command for transferring to an agent. See Deciding whether to use human agents in the deployed system for more information.
In some systems, the phrase “Operator” might be preferable to “Transfer to Agent”.
This command stops playback of the current prompt (unless you have disabled barge-in).
This command repeats the last prompt. (Refer to the description of the <reprompt> element in VoiceXML 2.0 for implementation details.) For example:
|
Note that in this example, the application has provided some information, then asked a question. In cases like this, the Repeat command should repeat the information and the question. The most likely scenario is that the user needs to hear the information again, not that the user has failed to understand or remember the question.
This command lets users start over when they want to abandon the path they are on and return to the beginning of the interaction. For example:
|
If your application contains multiple modules, it might not be clear at which point the system will restart. In this case, you might want to code a set of commands in global grammars to allow users to jump to the different modules or back to the main menu. For example, the commands LIBRARY, BANKING, CALENDAR, and MAIN MENU might be in global grammars for a voice portal application with library, banking, and calendar modules. If you have explicitly labeled the starting point of your application “Main Menu,” then you should accept the command MAIN MENU as well as START OVER.
Simply having these commands in the system is not sufficient to make them usable; you may need to let users know that they exist. You can accomplish this in three ways:
It is not always necessary or even desirable to list all of the global commands; remember that if the user accidentally or naturally speaks one that was not mentioned, it will still have the desired effect. First time users will rarely remember the commands, but this presentation can be helpful for repeat users. For example:
|
|
|