A grammar for writing dialogues, Robinson SRI 1980

  • Robinson, Jane J. "DIAGRAM: A Grammar for Dialogues" Artificial Intelligence Center SRI Technical Note 205, Feb. 1980. view details Abstract: This paper presents an explanatory overview of a
    large and complex grammar, DIAGRAM, that is used
    in a computer system for interpreting English dialogue.
    DIAGRAM analyzes all of the basic kinds of phrases
    and sentencek and many quite complex ones as well.
    It is not tied to a particular domain of application, and
    it can be extended to analyze additional constructions,
    using the formalism in which it is currently written.
    For every expression it analyzes, DIAGRAM provides
    an annotated description of the structural relations
    holding among its constituents. The annotations provide
    important information for other parts of the system
    that interpret the expression in the context of a
    DIAGRAM is an augmented phrase structure grammar.
    Its rule procedures allow phrases to inherit attributes
    from their constituents and to acquire attributes
    from the larger phrases in which they themselves
    are constituents. Consequently, when these attributes
    are used to set context-sensitive constraints on the
    acceptance of an analysis, the contextual constraints
    can be imposed by conditions on dominance as well as
    conditions on constituency. Rule procedures can also
    assign scores to an analysis, rating some applications
    of a rule as probable or as unlikely. Less likely analyses
    can be ignored by the procedures that interpret
    the utterance.
    In assigning categories and writing the rule statements
    and procedures for DIAGRAM, decisions were
    guided by consideration of the functions that phrases
    serve in communication as well as by considerations of
    efficiency in relating syntactic analyses to propositional
    content. The major decisions are explained and
    illustrated with examples of the rules and the analyses
    they provide. Some contrasts with transformational
    grammars are pointed out and problems that motivate
    a plan to use redundancy rules in the future are discussed.
    (Redundancy rules are meta-rules that derive
    new constituent-structure rules from a set of base
    rules, thereby achieving generality of syntactic statement
    without having to perform transformations on
    syntactic analyses.) Other extensions of both grammar
    and formalism are projected in the concluding section.
    Appendices provide details and samples of the lexicon,
    the rule statements, and the procedures, as well as
    analyses for several sentences that differ in type and