<?xml version="1.0" standalone="yes"?>
<Paper uid="P87-1006">
  <Title>GRAMl~IATICAL AND UNGRAMMATICAL STRUCTURES IN USER-ADVISER DIALOGUES1 EVIDENCE FOR SUFFICIENCY OF RESTRICTED LANGUAGES IN NATURAL LANGUAGE INTERFACES TO ADVISORY SYSTEMS. Raymonde Gulndon Aficeoelectroni~ and Computer Technology Corporation</Title>
  <Section position="3" start_page="0" end_page="0" type="intro">
    <SectionTitle>
INTRODUCTION
</SectionTitle>
    <Paragraph position="0"> It has been azgued that natural language interfaces with very rich functionality are crucial to the effective use of advisory systems and that interfaces using formal languages, menus, or direct manipulation will not suffice (Finin, Joshi, and Webber, 1986). Designing, developing, and debugging a rich natural language interface (its parser, grammar, recovery strategies from unparsable input, etc.) are time-consuming and labor-intensive. Nevertheless, natural language interfaces can be quite brittle in the face of uncon* strained input from the user, as can be found in applications such as user-advising. One step toward a solution to these problems would be the identification of a subset of gram* matical and ungrammatical structures that correspond to the language generated by users in any user-advising situations, irrespective of the domain. This subset could be used to design a core grammar, strategies to handle ungrammatical input, and some parsing heuristics portable to any natural language interface to advisory systems. This strategy would increase the habitability of the natural language interface (Watt, 1968; Trawick, 1983) and reduce its development cost.</Paragraph>
    <Paragraph position="1"> An important feature of this restricted subset is its independence from a particular domain (e.g., statistics, medicine}, making it portable. This is in contrast with another strategy which also capitalizes on restricted subsets of English, the use of sublanguages. There are naturally occurring subsets of English, usually associated with a particular domain or trade that have been called sublanguages (Harris, 1968; Kittredge, 1982). Sublanguages are characterized by distinctive specialized syntactic structures, by the occurrence of only certain domain-dependent word subclasses in certain syntactic combinations, and by the inclusion of specific ungrammatical forms (Sager, 1982). However, the association of * sublanguage with a particular domain and the emphasis on syntactic-semantic co-restrictions reduce the portability of a grammar defined on such a sublanguage.</Paragraph>
    <Paragraph position="2"> This paper presents an empirical characterization of users' language in an user-advising situation for the purpose of defining a domain-independent restricted subset of grammatical and ungrammatical structures to help design more habitable natural language interfaces to advisory systems.</Paragraph>
    <Paragraph position="3"> This paper also presents an interpretation of the factors that cause users to naturally limit themselves to a very restricted subset of English in typed communications between users and computerized advisers. We believe these factors will be found in any typed communications between users and advisers for the purposes of performing a primary task. Hence, the restricted subset of English should be general to any such situations.</Paragraph>
  </Section>
class="xml-element"></Paper>