|
Abstract:
Many theories of parsing have tried to answer the question of
what influences parsing decisions at the point of local syntactic
ambiguities. This study investigates a part of this very complex
issue, namely the influence of overt case marking on parsing
decisions at points of case ambiguities in Polish. Specifically, I
will address two questions:
1. Does the Case Hierarchy (Nominative > Accusative > ...)
or do general parsing principles govern initial structure analysis
at points of ambiguity, and
2. Do lexical cases and structural cases behave alike in early
parsing?
Using intuitions about processing preferences and processing
complexity elicited from six native speakers of Polish, I will
offer preliminary answers to these questions.
Case Theory distinguishes two types of cases which show
different syntactic behaviors: structural and lexical. Grammatical
case principles have to take this distinction into account. As for
structural case, Gorrell and Gunter (1997) showed for German that
in examples where an NP was ambiguously marked for Nominative or
Accusative and could be taken as a sentential conjunction in the
former case or as a conjoined NP in the latter, the subjects
preferred conjoined NPs. Hence, structural principles, such as
Minimal Attachment (Frazier, 1978, 1987; Frazier & Fodor, 1978;
Frazier & Clifton, 1997; de Vincenzi, 1991; and others) take
precedence in initial parsing decisions over a structural case
hierarchy. The same sentences reconstructed in Polish yield similar
results: in ambiguous examples, the parser is initially guided by
the structural principles, as the simpler structure is chosen over
a case higher on the structural case hierarchy.
The remaining question is the influence of lexical case
principles on initial parsing. In effect, lexical case requirements
are specified in the lexical entry of each item that assigns a
lexical case. Upon encountering such an assigner, the parser should
thus know that an NP with the appropriate case must be present.
Therefore, I propose the following Lexical Case Preference
Principle: the predicted lexical case is satisfied as soon as
possible. I identified several examples in Polish where relevant
ambiguities exist. They all show that this principle is employed
early in parsing. One of these examples is illustrated below: the
preposition od 'from' selects for a Genitive object. To test
whether the lexical case requirement must be satisfied immediately,
I constructed sentences with two NPs marked for Genitive following
the preposition od, one was the head noun of that preposition and
the other was a possessive:
The sentence in (1) is globally ambiguous: the prepositional
phrase can be understood as
from grandma's friend,
or
from friend's grandma.
The lexical case principle would demand that the first NP be the
head noun, bearing the Genitive assigned by the preposition. This
prediction was confirmed when the noun phrases inside the relevant
prepositional phrase are made longer. These examples and others
will be discussed in the poster, alongside with otherfactors
influencing the lexical case assignment, such as phrase length and
focus. Formal experiments and further research need to be done to
verify the importance of the lexical case principle on the initial
parsing.
|
