Grammatical Trigrams

                         John Lafferty
                   School of Computer Science
                   Carnegie Mellon University
                       April 23, 1996

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ABSTRACT
It is widely believed among speech and language researchers that the
incorporation of linguistic information should improve statistical models 
of natural language and benefit applications such as speech recognition.  
This belief has yet to be realized.  In this talk I will discuss some 
previous attempts for building more effective language models and present 
some new ideas that this past work suggests.  In particular, I will give 
an overview of current work at CMU to develop language modeling 
techniques that combine grammatical information with n-gram statistics.  
This work uses link grammar to extract structural information and 
exponential models to estimate probabilities.  After introducing the 
relevant concepts, I will discuss areas of recent work that make this 
approach practical, including techniques that help decrease the 
computational burden of parameter estimation and robust parsing 
algorithms that enable the approach to be applied to disfluent and 
ungrammatical speech.
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Seminar Schedule