<?xml version="1.0" standalone="yes"?>
<Paper uid="N06-1040">
  <Title>Probabilistic Context-Free Grammar Induction Based on Structural Zeros</Title>
  <Section position="6" start_page="318" end_page="318" type="concl">
    <SectionTitle>
5 Conclusion
</SectionTitle>
    <Paragraph position="0"> We described a method for creating concise PCFGs by detecting structural zeros. The resulting unsmoothed PCFGs have far higher accuracy than simple induced PCFGs and yet are very efficient to use.</Paragraph>
    <Paragraph position="1"> While we focused on a small number of simple non-terminal splits that fit the factorization we had selected, the technique presented is applicable to a wider range of possible non-terminal annotations, including head or parent annotations. More generally, the ideas and method for determining structural zeros (vs. sampling zeros) can be used in other contexts for a variety of other learning tasks.</Paragraph>
  </Section>
class="xml-element"></Paper>