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Re: Additional parameters to SpeechRecognition (was "Speech API: first editor's draft posted")

From: Glen Shires <gshires@google.com>
Date: Wed, 25 Apr 2012 10:42:57 -0700
Message-ID: <CAEE5bcgkNWrmwddhHrARQMyKqK_kTHSOTuikJnJ_s8EoCO8oZg@mail.gmail.com>
To: "Young, Milan" <Milan.Young@nuance.com>
Cc: Hans Wennborg <hwennborg@google.com>, Satish S <satish@google.com>, "public-speech-api@w3.org" <public-speech-api@w3.org>
I think (hope) that most web developers won't have to worry about
confidence values because the default set by the speech recognizer should
be sufficient.

However, a JS API developer savvy enough to understand how/when to properly
set a confidenceThreshold, is also savvy enough to intelligently process
the confidence values returned in the results. As Deborah mentioned [1],
"For example, if the top two alternatives in the nbest have very similar
confidences...".  Typically, processing the confidence result values is a
much better strategy than trying to tune the confidenceThreshold.

Only extremely savvy JS API developers will understand how to properly tune
the confidenceThreshold so that it prunes (but doesn't over prune) the data
returned.  I believe these developers can best adjust
the confidenceThreshold by processing the confidence result values returned
by prior recognitions (as opposed to simply bumping the default value by
0.05).


Also, from an implementation standpoint, there's a major issue with
making confidenceThreshold readable. If the developer switches to a new
recognizer, the default confidenceThreshold may change. If the developer
then reads the confidenceThreshold (for example, to increment it by 0.05),
then presumably the browser needs to get the default confidence value from
the speech recognizer. For a remote recognizer, this round-trip takes time,
and the browser cannot stall the javascript processing.

/Glen Shires

[1] http://lists.w3.org/Archives/Public/public-speech-api/2012Apr/0031.html

On Wed, Apr 25, 2012 at 9:47 AM, Young, Milan <Milan.Young@nuance.com>wrote:

>  The speech community has lived for 20 years with the fact that
> confidence values are not portable across engines.  I understand that we
> are courting a new class of developers with this HTML-based initiative, but
> I want to be careful not to dumb it down to the point where we impact the
> mainstream speech industry.****
>
> ** **
>
> Incrementally bumping up confidence (eg recognizer.confidence += 5) in
> response to a series of misrecognitions is a common technique.  I also find
> it generally ugly that confidence is special cased with a function instead
> of a property.  (Is it a JS limitation that you cannot mark a property as
> write only?)****
>
> ** **
>
> I would rather say something like “Recognition engines generally do a good
> job of choosing the right confidence value for a recognition task.  If you
> do choose to read this property, know that it’s value is not portable to
> other recognition tasks, other speech engines, or other user agents.”****
>
> ** **
>
> Thanks****
>
> ** **
>
> *From:* Glen Shires [mailto:gshires@google.com]
> *Sent:* Wednesday, April 25, 2012 8:11 AM
> *To:* Hans Wennborg
> *Cc:* Young, Milan; Satish S; public-speech-api@w3.org
>
> *Subject:* Re: Additional parameters to SpeechRecognition (was "Speech
> API: first editor's draft posted")****
>
> ** **
>
> confidenceThreshold****
>
> ** **
>
> I think we all agree that speech recognizers have a concept of confidence,
> and that it can be mapped to a monotonically increasing range of 0.0 to
> 1.0.  However, specific values (for example 0.5) do not correspond to the
> same level of confidence for different recognizers.****
>
> ** **
>
> I believe that if the developer does not set the confidenceThreshold, the
> speech recognizer should use a default value that is appropriate for that
> recognizer.****
>
> ** **
>
> A complication with a confidenceThreshold attribute is defining the
> default value (if the value is read, but not written, what value does the
> BROWSER return? - particularly because the optimal default value may vary
> from one RECOGNIZER to another).****
>
> ** **
>
> Perhaps instead of an attribute, this should be a write-only value,
> specifically a setConfidenceThreshold method.****
>
> ** **
>
> /Glen Shires****
>
> On Wed, Apr 25, 2012 at 6:43 AM, Hans Wennborg <hwennborg@google.com>
> wrote:****
>
> On Tue, Apr 24, 2012 at 17:22, Young, Milan <Milan.Young@nuance.com>
> wrote:
> > There are two reasons for including confidence that I would like this
> community to consider:
> >  Efficiency - Similar to the argument Satish put forward for limiting
> the size of the nbest array, pruning the result candidates at the server is
> more efficient.
> >  Clipping - There are many environments where background noise and side
> speech that can trigger junk results.  If confidence is low, this will
> trigger a result and then the application enters a deaf period where it
> processes the result and discovers the content is junk.  If real speech
> happens during this phase, its start will be missed.
> >
> > Every recognizer that was ever invented has a concept of confidence.
>  Yes, the semantics of that value vary across platforms, but for us to push
> this to a custom parameter will confuse developers, and ultimately slow
> adoption.****
>
> Ok, I don't feel strongly about this, so I would be fine adding a
> confidenceThreshold if others agree.****
>
>
> > Regarding the timeout family, an open-ended dialog like "Tell me what is
> wrong with your computer", should have generous timeouts.  Compare this to
> "So it's something to do with your new Google double mouse configuration,
> is that correct?" which should have short timeouts.
> >
> > Our goal should be a consistent application experience across UAs, and
> that's only going to happen if we standardize timeouts.  I would also like
> to mention that the definition of these timeouts is clear and has been
> industry standard for 10+ years.****
>
> What do you think about my idea of just letting the web page handle
> the timeout itself, calling abort() when it decides a request is
> taking too long?
>
>
> Thanks,
> Hans****
>
>
>
> ****
>
> ** **
>
> --
> Thanks!****
>
> Glen Shires****
>
> ** **
>



-- 
Thanks!
Glen Shires
Received on Wednesday, 25 April 2012 17:44:13 UTC

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