<?xml version="1.0" standalone="yes"?>
<Paper uid="E87-1037">
  <Title>A Comparison of Rule-Invocation Strategies in Context-Free Chart Parsing</Title>
  <Section position="6" start_page="5278" end_page="5278" type="concl">
    <SectionTitle>
5 Conclusion
</SectionTitle>
    <Paragraph position="0"> This paper has surveyed the fundamental rule-invocation strategies in context-free chart parsing. In order to arrive at some quantitative measure of their performance characteristics, the strategies have been implemented and tested empirically. The experiments clearly indicate that it is possible to significantly increase efficiency in chart parsing by fine-tuning the rule-invocation strategy. Fine-tuning however also requires that the characteristics of the grammars to be used are borne in mind. Nevertheless, the experiments indicate that in general directed methods are to be preferred to undirected methods; that top-down is the best undirected strategy; that Kilbury's original algorithm is not in itself a very good candidate, but that its directed versions -- in particular the one with both selectivity and top-down filtering -- are very promising.</Paragraph>
    <Paragraph position="1"> Future work along these lines is planned to involve application of (some of) the strategies above within a unification-based parsing system.</Paragraph>
  </Section>
class="xml-element"></Paper>