<?xml version="1.0" standalone="yes"?>
<Paper uid="W06-3301">
  <Title>The Semantics of a Definiendum Constrains both the Lexical Semantics and the Lexicosyntactic Patterns in the Definiens</Title>
  <Section position="12" start_page="6" end_page="7" type="concl">
    <SectionTitle>
10 Conclusions and Future Work
</SectionTitle>
    <Paragraph position="0"> This is the first study in definitional question answering that concludes that the semantics of a definiendum constrain both the lexical semantics and the lexicosyntactic patterns in the definition. Our discoveries may be useful for the building of a biomedical definitional question answering system.</Paragraph>
    <Paragraph position="1"> Although our discoveries (i.e., that the semantic types of the definitional terms determine both the lexicosyntactic patterns and the semantic types in the definitions) were evaluated with the knowledge framework from the biomedical, domain-specific knowledge resource the UMLS, the principles may be generalizable to any type of semantic classification of definitions. The semantic constraints may enhance both recall and precision of one-size-fits-all question answering systems, which may be evaluated in future work.</Paragraph>
    <Paragraph position="2"> As stated in the Discussion session, one disadvantage of this study is that the lexicosyntactic patterns generated by Autoslog-TS are within clauses.</Paragraph>
    <Paragraph position="3"> Future work needs to develop pattern-recognition systems that are capable of detecting patterns across clauses.</Paragraph>
    <Paragraph position="4"> In addition, future work needs to move beyond lexicosyntactic patterns to extract semantic-lexicosyntactic patterns and to evaluate how the semantic-lexicosyntactic patterns can enhance definitional question answering.</Paragraph>
    <Paragraph position="5">  Acknowledgement: The author thanks Sasha Blair-Goldensohn, Vijay Shanker, and especially the three anonymous reviewers who provide valuable critics and comments. The concepts &amp;quot;Definiendum&amp;quot; and &amp;quot;Definiens&amp;quot; come from one of the reviewers' recommendation.</Paragraph>
  </Section>
class="xml-element"></Paper>