IVR Deconstructed

In previous posts, we’ve compared VoiceXML to HTML and discussed the similarities in the way one would develop applications with both programming languages.  Because we often make this comparison, developers who are new to building voice applications often ask for example VoiceXML code, so we’ve listed some below.  In addition we’ve included links to some other great resources for developers.

The following example comes from the W3C’s Voice Extensible Markup Language (VoiceXML) Version 2.0 specification which can be found at http://www.w3.org/TR/voicexml20/:
VoiceXML is designed for creating audio dialogs that feature synthesized speech, digitized audio, recognition of spoken and DTMF key input, recording of spoken input, telephony, and mixed initiative conversations. Its major goal is to bring the advantages of Web-based development and content delivery to interactive voice response applications.

Here are two short examples of VoiceXML. The first is the venerable “Hello World”:

<?xml version=”1.0″ encoding=”UTF-8″?>
<vxml xmlns=”http://www.w3.org/2001/vxml”
xmlns:xsi=”http://www.w3.org/2001/XMLSchema-instance”
xsi:schemaLocation=”http://www.w3.org/2001/vxml
http://www.w3.org/TR/voicexml20/vxml.xsd”
version=”2.0″>

<form>
<block>Hello World!</block>
</form>
</vxml>

The top-level element is <vxml>, which is mainly a container for dialogs. There are two types of dialogs: forms and menus. Forms present information and gather input; menus offer choices of what to do next. This example has a single form, which contains a block that synthesizes and presents “Hello World!” to the user. Since the form does not specify a successor dialog, the conversation ends.

Our second example asks the user for a choice of drink and then submits it to a server script:

<?xml version=”1.0″ encoding=”UTF-8″?>
<vxml xmlns=”http://www.w3.org/2001/vxml”
xmlns:xsi=”http://www.w3.org/2001/XMLSchema-instance”
xsi:schemaLocation=”http://www.w3.org/2001/vxml
http://www.w3.org/TR/voicexml20/vxml.xsd”
version=”2.0″>

<form>
<field name=”drink”>
<prompt>Would you like coffee, tea, milk, or nothing?</prompt>
<grammar src=”drink.grxml” type=”application/srgs+xml”/>
</field>

<block>
<submit next=”http://www.drink.example.com/drink2.asp”/>
</block>
</form>
</vxml>

A field is an input field. The user must provide a value for the field before proceeding to the next element in the form. A sample interaction is:
C (computer): Would you like coffee, tea, milk, or nothing?
H (human): Orange juice.
C: I did not understand what you said. (a platform-specific default message.)
C: Would you like coffee, tea, milk, or nothing?
H: Tea
C: (continues in document drink2.asp)

For more VoiceXML examples, please visit Plum’s developer documentation page at VoiceXML Documentation

The VoiceXML Forum is another great resource for information about the VoiceXML community.

Recently there’s been an emergence of new communication services that offer simple APIs and scripting languages to create basic IVR applications.  Some of these services include added features that come standard with most VoiceXML platforms including speech recognition and text-to-speech, but why do we need more scripting languages to create IVR when VoiceXML is open and so widely adopted?  Billions have been spent on R&D to create VoiceXML and it is truly the de facto open standard for IVR programing.

These services are offered under the guise of “cloud” communications and attempt to simplify IVR development.  While they do have their merits, they seem to simplify IVR by eliminating features that amount to a weak subset of VoiceXML’s functionality.  Regarding the “cloud” aspect, for years Plum’s ScratchPad has provided a facility for developers to host their VoiceXML code enabling an architecture akin to “cloud” computing.   Programmers can use the ScratchPad to develop applications using the full breadth of VoiceXML’s feature set.

For more information about IVR development and Plum’s ScratchPad, please sign up for a developer account @ IVR Development

TMC recently wrote an article about Plum’s new outbound IVR features.  The article can be found here: Outbound IVR

The new outbound IVR features include the following:

▪    Throttling options to control the flow and speed of outbound calls.
▪    Comprehensive downloadable reports and analytics.
▪    Advanced retry and callee detection options.
▪    If an IVR survey has reached its respondent limit, all campaigns running for that survey will be paused and the status indicated when viewing the campaign is “Max Respondents Reached”.

These features can be used to improve all outbound IVR call campaigns including:

Customer Satisfaction Surveys
Political Polling
Payment Collections
Medical Reminders
Appointment Reminders
Emergency Notifications
Prescription Refills
Travel Updates

Please feel free to sign up for a free developer or Plum Survey account at http://www.plumvoice.com/

So, today being the Boston Marathon, I thought about how useful IVR could be for an event like this. A couple of years ago, my uncle had run the Boson Marathon and I remember how difficult it was to find him after the race.

So, I thought, why not have an IVR system set up to call the family members of runners to inform them that the runner has finished the race and where the runner is now located.

This solves 2 problems:

1) Suppose the weather is cold and rainy. If the family members don’t want to wait outside the entire time, they can wait in an indoor location and head out once they receive the IVR call.

2) Runners wouldn’t have to wait long for their family members to show up. As exhausted as they might be, I’m sure they’d hate to wait for half an hour.

Just another idea of how IVR can improve our daily lives.

We’re pondering a new extension to VoiceXML for our IVR platform: conferencing. We currently have it working in the lab and it works on a single server quite well. Our approach to this problem is, we believe, quite clever. We’ve introduced a new tag: <conf>. Simply specify a conference name and you’ll be connected to that conference. Anyone else who selects that same name will, in turn, be connected to the same conference. Behind the scenes, the IVR is actually doing a 32-bit hash on the name in order to come up with a unique ID with which to identify the conference. With a <conf> tag, you can blend conferencing into any call flow at any time, freely and naturally. Plus, it can be enhanced with additional audio control attributes that alter input and output volume (thus allowing you to create virtual townhall meetings) as well as timing controls to limit conference length.