Combining Grammars for Improved Learning Combining Grammars for Improved Learning
نویسندگان
چکیده
We report experimental work on improving learning methods for probabilis-tic context-free grammars (PCFGs). From stacked regression we borrow the basic idea of combining grammars. Smoothing, a domain-independent method for combining grammars, does not ooer noticeable performance gains. However , PCFGs allow much tighter, domain-dependent coupling, and we show that this may be exploited for signiicant performance gains. Finally, we compare two strategies for acquiring the varying grammars needed for any combining method. We suggest that an unorthodox strategy, \leave-one-in" learning, is more eeective than the more familiar \leave-one-out".
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