Re: Prompt interface question

[Derek Seabury <Derek.Seabury@speechworks.com>]

Well, the nice thing about builtin grammars is that you can cheat...  In just
JSGF it would be really hard to write a grammar for credit cards for example.
In a builtin you can throw in callbacks to throw out invalid results or end
recognition early.

In SpeechWorks BNF grammars we allow additional constraints such as:
{ $TRAVEL_CMD = I want to fly from $ORIGIN to $DESTINATION;
$ORIGIN != $DESTINATION;
}
But for things like credit cards we would have a callback function associated
with parts of the grammar that would let us throw out hypotheses with invalid
digits or checksums.  This of course doesn't translate well to remote
execution... but you can do it in a builtin.

In the mean time, maybe it would be worth while to write a DTMF grammar handler
for the stub recognizer.  Because grammar formats for VoiceXML 1.0 aren't
specified this could be whatever is convenient with the additional ability to
handle overlays of links, menu, etc.

As a side note, in the proposed W3C grammar formats for VoiceXML 2.0 there will
be support for similar constraints and processing in the grammar itself.
Currently there is debate on whether the language for this should be ECMA
script, a subset, or something completely different.

Derek

--
S. Derek Seabury
Marketing Manager, Emerging Technologies
SpeechWorks International
Derek.Seabury@SpeechWorks.com
(617)428-4444