Eckhard Bick - VISL

constituent trees. Advantages and draw-backs of different notational systems of
parsing output will be weighed regarding computational and pedagogical aspects as
well as the expression of ambiguity.
Chapter 5 treats valency tagging, focusing not so much on valency patterns as such
(which are treated in chapters 3 and 4), but rather on the role of valency tags as an
intermediate CG stage linking syntactic to semantic parsing. Also, I will defend why
using syntactic function tags for the instantiation of lexically derived tags for
valency potential is not a kind of self-fulfilling prophecy, but a productive part of
grammatical analysis.
In Chapter 6, I will discuss the highest - and most experimental - level of CG based
Progressive Level Parsing, - semantics. It is the semantic level that most clearly
shows the disambiguation potential residing in the interplay of tags from different
levels of grammatical analysis. Thus, morphosyntactic tags and instantiated valency
or dependency tags will be exploited alongside semantic tags proper and hybrid tags
imposing semantic restrictions on tags for valency potential. Teleologically,
polysemy resolution will be treated from a bilingual Portuguese-Danish perspective,
allowing differentiation of translation equivalents. I will argue that - by using
minimal distinction criteria and atomic semantic features for the delineation of
semantic prototypes - semantic tagging is entirely possible without achieving full
definitional or referential adequacy. However, though a complete system of semantic
tagging will be presented for nouns, and a basic one for verbs and adjectives, and
though the tag set has been incorporated into the whole (Portuguese) lexicon, the CG
rule body concerned with semantics is still small compared to the rule sets used for
lower level parsing. Therefore, definite conclusions cannot be drawn at present, and
performance testing had to be sketchy and mostly qualitative at this level 5 .
Chapter 7, finally, explores some of the possible applications of the parser, machine
translation, corpus tools and grammar teaching programs. Corpus annotation is the
traditional field of application for a parser, not much additional programming is
needed, and an annotation is about as good or bad as the parser performing it 6 . In
machine translation, however, parsing (even semantic parsing) solves only “half the
task”, since choosing translation equivalents and performing target language
generation evidently cannot be achieved without additional linguistic processing. I
will show how an additional layer of CG rules can be used not for analysis, but for
generation, and how CG tag context can be exploited for syntactic transformations
and morphological generation. Grammar teaching on the internet, on the other hand,
is an example where the parser forms not the core of a larger linguistic program
5 A three year research grant (1999-2001) from Statens Humanistiske Forskningsråd, at Odense University, for a project
involving Portuguese, English and Danish CG semantics, is hopefully going to change that.
6 Most annotation today still means tagging with word based PoS tags, which are easy to handle with string searching
tools, but lack syntactic information. The CG-approach, however, is robust and word based even on the syntactic level,
allowing syntactic tag searches in the same fashion as used for PoS tags.
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