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<Paper uid="P93-1044">
  <Title>Guiding an HPSG Parser using Semantic and Pragmatic Expectations</Title>
  <Section position="6" start_page="296" end_page="296" type="evalu">
    <SectionTitle>
EVALUATION &amp; TESTING
</SectionTitle>
    <Paragraph position="0"> The techniques described here have been used successfully to guide the parsing of several sentences taken from real conversations. The pragmatic and semantic knowledge already existed from Patten's research (Patten, 1992) to generate these sentences. A subset of this knowledge, judged to represent the partial knowledge available to a listener, was used to generate expectations in the form described above.</Paragraph>
    <Paragraph position="1"> The parser used in this study by default produced all possible parses. The modified version attempts to converge on the &amp;quot;expected&amp;quot; parse first, and terminate. For each sentence tested the parser converges on the correct parse first. When the expectations are modified to expect a different parse, a different (and correct) parse is found first. The results in terms of speedup vary considerably depending on the level of ambiguity present in the sentence. The most complex sentence parsed thus far exhibits considerable speedup. When unguided, the parser produces 24 parses, and considers a total of 252 distinct constituents. In the guided case, the parser only considers 39 constituents, and converges on the one &amp;quot;correct&amp;quot; parse first. Within the current testing environment, this guidence results in a greater then ten-fold speedup in terms of CPU time.</Paragraph>
  </Section>
class="xml-element"></Paper>