SEMANTIC PLAUSIBILITY AND CATEGORY EFFECTS ON 
UNBOUNDED DEPENDENCY PROCESSING IN TURKISH RELATIVE CLAUSES

Şükrü Barış Demiral
September,2001

Unbounded dependencies represent special types of
constructions to understand initial preferences of human language
parser. How the language parser relates unbounded items is the
main concern of both psycholinguists and computational linguists.
In order to understand syntactic and semantic constraints in
initial parsing preferences, varieties of sentence types for
different languages have been constructed. Turkish, with its
characteristic syntactic and morpho-syntactic structure, enables
us to observe the behavior of the parser on different categories
and constituents. This thesis aims to find out syntactic and
semantic constraints used by the parser to form unbounded
dependencies as it proceeds on Turkish relative clauses. In order
to observe initial parsing preferences of the parser, a self-paced
reading experiment was conducted. In this experiment, some parts
of the sentences, which were difficult to parse, caused long
reading times when they were compared with the reading times of
the base condition. It has been observed that syntactic
constraints, lexical category information and semantic
plausibility affected parsing. The verb of the relative clause
assigned its thematic expectancy on the following words
immediately. Our findings indicate that verb-specific information
is processed in a very fast manner such that thematic features
generated by the verb direct the parsing process. The results of
the experiment are in accord with the constraint-based models of
parsing.

Keywords:Unbounded Dependency, Parsing Decisions, Syntax, Category Information,
Semantic Plausibility, Turkish Relative Clauses, Self-Paced
Reading Experiment, Thematic Expectancy, Constraint-Based
Accounts