Implementing form-filling dialogs

In order to implement form-filling dialogs it is necessary to:

• Create a data structure to represent the slots that will hold the information that the system has to elicit from the user.

• Develop an algorithm to process the slots, extracting the required prompts for each of them.

VoiceXML (http://www.w3.org/TR/voicexml20/) provides a useful structure for this task in terms of forms containing fields that represent the different items of information (slots) required to complete the form. The following code is an example:

  <form id = "flight">
  <field name="destination">
  <prompt>where would you like to travel to?</prompt>
  <grammar src = "destinations.grxml"/>
  </field>
  <field name="date">
  <prompt>what day would you like to travel?</prompt>
  <grammar src = "days.grxml"/>
  </field>
  </form>

The preceding example shows an app that asks for two pieces of information: destination and...