Arabic writing is typically underspecified for short vowels and other markups, referred to as diacritics. In addition to the lexical ambiguity exhibited in most languages, the lack of diacritics in written Arabic adds another layer of ambiguity which is an artifact of the orthography. In this paper, we present the details of three annotation experimental conditions designed to study the impact ...

A number of previous experiments on the role of lexical ambiguity, in Information Retrieval are reproduced on the'IR-Semcor test collection (derived from Semcor), where both queries and documents are hand-tagged ;with phrases, Part-Of-Speech and WordNet 1.5 senses. Our results indicate that a) Word Sense Disambiguation can be more beneficial to Information Retrieval than the experiments of Sand...

This paper describes an approach to the automatic identification of lexical information in on-line dictionaries. This approach uses bootstrapping techniques, specifically so that ambiguity in the dictionary text can be treated properly. This approach consists of processing an on-line dictionary multiple times, each time refining the lexical information previously acquired and identifying new le...

The effects of prior semantic context upon lexical access during sentence processing were examined for three groups of subjects; nonfluent agrammatic (Broca's) aphasic patients; fluent (Wernicke's) aphasic patients; and neurologically intact control patients. Subjects were asked to comprehend auditorily presented, structurally simple sentences containing lexical ambiguities, which were in a con...

Retrieval systems implementing query-based search routinely encounter difficulties related to lexical ambiguity. Frequent attempts have been made in the fields of Information Retrieval (IR), Artificial Intelligence (AI) and Natural Language Processing (NLP) to address this problem, yet it remains unsolved. This thesis introduces a novel methodology known as co-active search that expresses the u...

S. Joordens and D. Besner (1994) described an attempt to simulate a semantic ambiguity advantage in lexical decision using a connectionist model (Masson, 1991) that was based on a Hopfield (1982) network. The question of the validity of the ambiguity advantage is briefly considered, and the assumptions behind the simulation results reported by Joordens and Besner are critically examined. The mo...

Research into the processing of lexical ambiguities has provided a valuable paradigm for investigating the functional architecture of the language processing system in normal and neurologically impaired populations and specifically, how basal ganglia circuits and the neurotransmitter dopamine may act to enhance and/or suppress various meanings relative to the context in which the lexical ambigu...

One of the main problems in Natural Language Processing is lexical ambiguity, words often have multiple lexical functionalities (i.e. they can have various parts-of-speech) or have several semantic meanings. Nowadays, the semantic ambiguity problem, most known as Word Sense Disambiguation, is still an open problem in this area. The accuracy of the different approaches for semantic disambiguatio...

We describe a corpus-based approach to creating a semantic lexicon using UMLS knowledge sources. We extracted 10,000 sentences from the eligibility criteria sections of clinical trial summaries contained in ClinicalTrials.gov. The UMLS Metathesaurus and SPECIALIST Lexical Tools were used to extract and normalize UMLS recognizable terms. When annotated with Semantic Network types, the corpus had...

The traditional framework ['or ambiguity resolution employs only 'static' knowledge, expressed generally as selectional restrictions or domain specific constraints, and makes uo use of any specific knowledge manipulation mechanisms apart from the simple ability to match valences of structurally related words. In contraust, this paper suggests how a theory of lexical semantics making use of a kn...