negative weights for meging language models

[Andreas Stolcke]

In message <136aa037050512180056587e9b at mail.gmail.com>you wrote:
> Hi
> 
> I am tring to implement the Anti language model approach used in the
> "THE SRI MARCH 2000 HUB-5 CONVERSATIONAL SPEECH TRANSCRIPTION SYSTEM"
> 
> This requires the use of a negative weight on a language model. Is it
> possible to do this in the toolkit? The ngram tool lets you specify
> the weight on the primary language model but does not allow a negative
> weight on the mixture language model. Does some other tool allow
> negative weights?

You shouldn't try to (linealy) interpolate the anti-LM wiht the 
regular LM.  The combination uses a log-linear interpolation.
This is typically done when resoring nbest lists or lattices.
You just specify the regular LM and the anti-LM scores separately,
and a negative scaling factor for the latter.

--Andreas