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RE: VoiceXML vs SALT

From: Royles, Chris <Chris.Royles@vicorp.com>
Date: Sun, 26 Oct 2003 16:02:51 -0000
Message-ID: <A10DE5600B42CB4EABF446C98C053B8E047B22@Bulldog.vicorp.co.uk>
To: 'Ildar Gabdulline' <ildar@realeastnetworks.com>
Cc: "'www-voice@w3.org'" <www-voice@w3.org>
Wow - that was a brave statement to make on the w3c forum.
Other people, especially those more involved may have a different slant on
this than I do. Also I am not clear about what 'information' you are after
or why you wish to make this comparison. But from standing on the sidelines,
I see them as follows...
First, SALT and VxML cannot really be compared with each other on the same
terms, they have different goals, although there are times when the
technologies they use overlap.
 - VxML is a culmination of many different groups (Now the Voice Browser
working group) bringing together different ideas to solve a problem, the
VxML standard  is currently being developed by the W3C. The problem they are
trying to solve, is to simplify the differeing proprietary technologies used
for building IVR services and callflows, this was a big problem in the
industry about 5 years ago. It was difficult to port one voice IVR solution
to a different platform. VxML is typically interacted with, by the user over
a telephone, it runs on the server and is used by the engine as a script for
how to handle the call.
I use VxML daily to define services that execute within an IVR environment.
The VxML browser built into the telephony application interprets the VxML
and generates a resulting navigation through a service. The VxML is a small
part of a much larger infrastructure supporting ASR, TTS and Call control
facilities. The statement "Its major goal is to bring the advantages of
web-based development and content delivery to interactive voice response
applications" probably sums up the basics.
 - SALT is a standard introduced by another group (
<http://www.saltforum.org/default.asp#FounderComments> ) of reasearch and
industry experts, it provides 'integration' with existing markup languages
such as HTML to provide new 'voice enabled', multimodel interfaces. I
consider SALT as trying to 'introduce a new technology', in the form of
multimodal interaction. The SALT language is typically interpreted on the
client. An example would be downloading HTML content to view on your
hand-held device, the browser rendering the HTML can also interpret SALT
tags,  providing a voice interface to the dialogs and forms within the HTML
content. This is a mulitmodal interface. I always consider SALT closer to
SMIL than to VxML. I think the key statement is "The Speech Application
Language Tags extend existing mark-up languages such as HTML, XHTML, and
XML." http://www.saltforum.org/default.asp#About%20SALT
There is certainly scope for having both standards, as they approach
different problems from different directions. In some cases the two
technologies can be complementary. Having a SALT enabled multimodal dialog
with rich visual content pushed to enhanced clients, while still providing
standard voice only IVR interfaces using VxML.
Does anybody have any papers or reasearch that has studied this question? I
always see scope for looking at the overlap between these two languages. It
would be good to develop the definition of a dialog once, yet still be able
to present that dialog as both VxML or SALT (or SMIL) based on the
regards, Chris Royles
Vicorp                  Dr Christopher Royles
Wexham Springs          Senior Software Engineer
Framewood Road          +44 (0)1753 660 583
Wexham                  +44 (0)1753 660 501
SL3 6PJ                 chris.royles@vicorp.com
Great Britain            <http://www.vicorp.com> http://www.vicorp.com

-----Original Message-----
From: Ildar Gabdulline [mailto:ildar@realeastnetworks.com]
Sent: 26 October 2003 15:21
To: www-voice@w3.org
Subject: VoiceXML vs SALT

I am relatively new to voice dialogs.
Could you please describe me - what are the differences between VoiceXML and
As I understood for the moment both of them are used for the same purposes -
programming of the dialogs.
If this is correct then it seems that having two standard families is
Please clarify the situation, if it is possible.
Received on Sunday, 26 October 2003 11:04:26 UTC

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