SEMANTIC FEATURES AND SELECTION RESTRICTIONS
3. SEMANTIC FEATURES IN SYSTEMS OF NATURAL LANGUAGE PROCESSING (NLP)
Semantic Features in NLP
Crucial Role
Semantic features play a crucial role in natural language processing (NLP).
Predicate-Argument Relations
Contribute to revealing predicate-argument relations in parsing algorithms.
Disambiguation
Aid in disambiguating lexically homonymous words
Combinability
To assist in the combinability of verbs with
Adverbials
Coordinated constructions
Anaphoric Relations
Help identify anaphoric relations in text
Interpretations
A distinction is made between:
Literal interpretations
Deviant or metaphorical meanings
Overall Importance
Essential for an analysis either:
Syntactic
semantic analysis in NLP
4. SEMANTIC FEATURES AND SELECTION RESTRICTIONS IN LEXICON AND GRAMMAR
Semantic features were a primary tool for semantic analysis in the early 1960s
but took a backseat in the 1970s and 1980s with advancements in semantic theory.
The notion of semantic features is gaining prominence again
particularly in understanding selection restrictions in lexicon and grammar.
Anna Wierzbicka suggests that grammatical distinctions are motivated by
semantic distinctions
arguing that semantic features play a leading role in regulating selection restrictions.
Examples demonstrate how seemingly syntactic selection restrictions can be semantically motivated
such as predicates allowing Neg-Raising
or the distribution of Russian conjunctions "что" and "как" based on semantic components.
Semantic invariants are identified for predicates capable of introducing indirect questions
showing the influence of semantic components like "X knows" in linguisticstructures.
Examples:
Neg-Raising predicates
have semantic features like
[+Incompatibility of contraries]
[+Excluded neutrality].
Russian conjunctions что and как are used based on semantic components;
что follows verbs with 'know/believe',
while как follows words with 'perceive'.
Predicates introducing indirect questions or parameters are determined by the semantic component'Xknows'.
5. ON SEMANTIC IN-VARIANT OF THE CLASS OF WORDS WITH GENITIVE SUBJECT
Semantic features were crucial for semantic analysis in the 60s
but have since taken a secondary position in natural language processing.
Semantic features
can label components in lexical meanings and play a role in semantic decomposition.
Semantic features
may regulate selection restrictions in lexicon and grammar more than syntactic features.
Anna Wierzbicka
argues that all selection restrictions in grammar can be motivated by semantic features.
Examples demonstrate
how semantic components influence selection restrictions in Russian grammar.
Negation of existence and presence in the field of vision
are key semantic components influencing genitive subject constructions.
Different semantic components account for the choice of genitive subjects in negative sentences.
The semantic invariant of genitive verbs allows for the characterization of semantic classes.
There is a connection between selectional restrictions and semantic features of words.
The presence vs. absence of semantic components influences the grammatical structureofsentences.
Examples:
Examples of sentences with genitive subjects in Russian:
"Ответа не пришло" (No answer came), "Мороза не чувствуется" (The frost is not felt)
"Катастрофы не произошло" (No catastrophe happened).
Semantic explanation
for the choice of case in genitive subject construction.
Semantic components
determining the selection of genitive subjects: 'X exists' and 'X is present in the field of vision of an observer'.
Different meanings
conveyed by genitive and nominative subjects in negative sentences.
Factors influencing the choice of genitive subject
animate vs. inanimate subject, referentiality, topic-focus articulation, presence vs. absence oftheobserver.
1. LEXICAL DATABASE OF THE SYSTEM
Main characteristics
Lexical Database (LBD) and Bibliographical Database (BBD)
Are key components of the Lexicographer expert system for natural language processing.
LBD contains machine-readable vocabulary
Morphological
Syntactic
Semantic
Prosodic
and referential features of lexical items.
Semantic features
speech act verbs
performative verbs
verbs of motion
kinship terms
body parts
BBD includes bibliographic information
Individual lexemes
unlike existing bibliographic catalogs.
The vocabulary comprises approximately 12,500 words
with morphological information sourced from Zalizniak's dictionary.
Syntactic and semantic information is often absent in existingdictionaries.
2. SEMANTIC FEATURE ACCORDING TO U.WEINREICH
Semantic Features
Central Role
Semantic features play a central role in the paper.
U. Weinreich's Contributions
Proposed a distinction between paradigmatic and transfer semantic features
Semantic features serve multiple purposes.
Explain deviant and metaphorical readings in language.
Impose provisional semantic contents on potentially ambiguous words.
Types of Semantic Features
Categorial Features
Pertains to the inherent characteristics of a word
Transitive Features
Imposes semantic conditions on arguments in a sentence
Application to Verbs
Verbs of Emotional State
Have specific transitive features
Verbs of Motion
Require certain categorial features in their arguments