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<Paper uid="P98-1046">
  <Title>Investigating regular sense extensions based on intersective Levin classes</Title>
  <Section position="3" start_page="0" end_page="0" type="intro">
    <SectionTitle>
1 Introduction
</SectionTitle>
    <Paragraph position="0"> The difficulty of achieving adequate hand-crafted semantic representations has limited the field of natural language processing to applications that can be contained within well-defined subdomains. The only escape from this limitation will be through the use of automated or semi-automated methods of lexical acquisition. However, the field has yet to develop a clear consensus on guidelines for a computational lexicon that could provide a springboard for such methods, although attempts are being made (Pustejovsky, 1991), (Copestake and Sanfilippo, 1993), (Lowe et al., 1997), (Dorr, 1997).</Paragraph>
    <Paragraph position="1"> The authors would like to acknowledge the support of DARPA grant N66001-94C-6043, ARO grant DAAH04-94G-0426, and CAPES grant 0914/95-2.</Paragraph>
    <Paragraph position="2"> One of the most controversial areas has to do with polysemy. What constitutes a clear separation into senses for any one verb, and how can these senses be computationally characterized and distinguished? The answer to this question is the key to breaking the bottleneck of semantic representation that is currently the single greatest limitation on the general application of natural language processing techniques.</Paragraph>
    <Paragraph position="3"> In this paper we specifically address questions of polysemy with respect to verbs, and how regular extensions of meaning can be achieved through the adjunction of particular syntactic phrases. We base these regular extensions on a fine-grained variation on Levin classes, intersective Levin classes, as a source of semantic components associated with specific adjuncts.</Paragraph>
    <Paragraph position="4"> We also examine similar classes in Portuguese, and the predictive powers of alternations in this language with respect to the same semantic components. The difficulty of determining a suitable lexical representation becomes multiplied when more than one language is involved and attempts are made to map between them.</Paragraph>
    <Paragraph position="5"> Preliminary investigations have indicated that a straightforward translation of Levin classes into other languages is not feasible (Jones et al., 1994), (Nomura et al., 1994), (Saint-Dizier, 1996). However, we have found interesting parallels in how Portuguese and English treat regular sense extensions.</Paragraph>
  </Section>
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