<?xml version="1.0" standalone="yes"?>
<Paper uid="C92-2099">
  <Title>ACQUISITION OF SELECTIONAL PATTERNS</Title>
  <Section position="9" start_page="0" end_page="0" type="concl">
    <SectionTitle>
8 Conclusion
</SectionTitle>
    <Paragraph position="0"> We have described two different approaches to evahtating automatically collected selectional patterns: by comparison to a set of manuallyclassified patterns and in terms of their effectivehess in selecting correct parses. We have shown that, without any manual selection of the parses or patterns ilt our trMning set, we are able to obtain selectioual p~tterns of quite satisfactory recall and precision, and which perform better than a set of manual selectional patterns in se~ lecting correct parses. We are not aware of any comparable etlorts to evaluate a hdl range of automatically acquired selectional patterns.</Paragraph>
    <Paragraph position="1"> Further studies are clearly needed, particularly of the best way in which the collected triples can be used for selection. The expected likelihood estimator is quite crude and more robust estimators should be tried, particularly given the sparse nature of tim data. We should experiment with better ways of combining of triples and pairs data to give estimates of semantic validity. Finally, we need to explore ways of combining these autotactically collected patterns with manually generated selectional patterns, which will probably have narrower coverage but may be more precise and complete for the w~rbs covered.</Paragraph>
  </Section>
class="xml-element"></Paper>