Lexical vagueness is a ubiquitous phenomenon in natural language. Most of previous works in natural language processing (NLP) consider lexical ambiguity as the main problem in natural language understanding rather than lexical vagueness. Lexical vagueness is usually considered as a solution rather than a problem in natural language understanding since precise information is usually failed to be provided in conversations. However, lexical vagueness is obviously an obstacle in human robot interaction (HRI) since the robots are expected to precisely understand their users' utterances in order to provide reliable services to their users. This research aims to develop novel lexical vagueness handling techniques to enable service robots to precisely understand their users' utterance so that they can provide the reliable services to their users. A novel integrated system to handle lexical vagueness is proposed in this research based on an in-depth understanding of lexical ambiguity and lexical vagueness including why they exist, how they are presented, what differences are in between them, and the mainstream techniques to handle lexical ambiguity and lexical vagueness. The integrated system consists of two blocks: the block of lexical ambiguity handling and the block of lexical vagueness handling. The block of lexical ambiguity handling first removes syntactic ambiguity and lexical ambiguity. The block of lexical vagueness handling is then used to model and remove lexical vagueness. Experimental results show that the robots endowed with the developed integrated system are able to understand their users' utterances. The reliable services to their users, therefore, can be provided by the robots.

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / O objetivo principal deste trabalho é estudar estratégias de indeterminação de sentido em um corpus de conversas telefônicas interceptadas, considerando que a produção de sentido é um processo cognitivo dependente do contexto. Delimitamos a linguística cognitiva como a área na qual essa pesquisa se encontra inserida, para melhor compreender os fundamentos e os pressupostos norteadores da Teoria dos Modelos Cognitivos Idealizados (TMCI) e da Teoria da Mesclagem Conceptual (blending), tendo como base, principalmente, os estudos de Lakoff (1987), Fauconnier (1997) e Fauconnier e Turner (2002). No decorrer do trabalho propomo-nos responder às seguintes questões de pesquisa: a) que estratégias de indeterminação de sentido são mais frequentemente usadas nestas conversas? b) que elementos do contexto e do cotexto permitem a delimitação do sentido do item lexical em determinada conversa? c) como funcionam, no corpus, as estratégias de indeterminação de sentido e de que forma elas contribuem para sustentar determinado tipo de relação interpessoal? Para responder a estas questões de pesquisa, das 22 gravações de conversas telefônicas de atores sociais envolvidos com tráfico de armas e drogas, sequestro e extorsão, fornecidas pela Coordenadoria de Segurança e Inteligência do Ministério Público do Rio de Janeiro, selecionamos 10 conversas, em função da sua qualidade sonora, para serem transcritas e para proceder à análise qualitativa do uso da polissemia e da vagueza lexical. A partir das discussões teóricas e das análises desenvolvidas, concluímos que a polissemia representa a estratégia de indeterminação de sentido mais frequente no corpus desta pesquisa e que a mesma pode ser entendida como um processo de mesclagem conceptual, que sofre influências sociais e culturais: é a dinamicidade do pensamento e da linguagem que geram a polissemia. Concluímos também que a vagueza lexical é utilizada, no corpus, como um recurso linguístico para referência a assuntos ilícitos. Os itens lexicais analisados instanciam esquemas mentais abstratos que têm seus sentidos realizados a partir de pistas linguísticas e extralinguísticas que apontam para um processo interacional que pode ser entendido como um enquadre de transações comerciais (tráfico de drogas) / The main objective of this research is to study strategies of indeterminacy of meaning in a corpus of intercepted telephone conversations by social actors involved with the trafficking of drugs and weapons, with kidnapping and extortion. We elected Cognitive Linguistics as the area in which this research should be developed, as we understand the process of meaning production as a cognitive process, dependent on the context. Within Cognitive Linguistics, we adopted the principles and assumptions guiding the Theory of Idealized Cognitive Models (TMCI) and Conceptual Blending Theory, based principally on studies by Lakoff (1987), Fauconnier (1997) and Fauconnier and Turner (2002). Throughout the paper our purpose is to answer the following research questions: a) what strategies for the indeterminacy of meaning are most often used in these conversations? b) what elements of context and co-text (the immediate grammatical context ) trigger the instantiation of the meaning of a lexical item in a particular conversation? c) how do the strategies of indetermination of meaning operate , in the corpus, and how do they contribute to the creation of a particular kind of interpersonal relationship? In order to answer these questions, from the 22 recordings provided by the Coordinator of Intelligence and Security of the Public Ministry of Rio de Janeiro, we selected 10 conversations, on the basis of their sound quality. We further transcribed them and submitted them to qualitative analysis, investigating the use of lexical polysemy and vagueness. From the theoretical discussions and analyzes undertaken, we conclude that polysemy represents the strategy of indeterminacy of meaning that is most often used in the corpus and that it can be understood as a process of conceptual blending, under the influence of social and cultural factors: it is the association between the use of language and the real dynamics of thought and language that generate polysemy. We also conclude that lexical vagueness is used as a language resource to refer to illicit affairs. The lexical items studied instantiate abstract mental schemas whose meanings are triggered by the use of particular linguistic and extralinguistic cues, within the domain, or frame, of a commercial transaction (drug trafficking)

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / O objetivo principal deste trabalho é estudar estratégias de indeterminação de sentido em um corpus de conversas telefônicas interceptadas, considerando que a produção de sentido é um processo cognitivo dependente do contexto. Delimitamos a linguística cognitiva como a área na qual essa pesquisa se encontra inserida, para melhor compreender os fundamentos e os pressupostos norteadores da Teoria dos Modelos Cognitivos Idealizados (TMCI) e da Teoria da Mesclagem Conceptual (blending), tendo como base, principalmente, os estudos de Lakoff (1987), Fauconnier (1997) e Fauconnier e Turner (2002). No decorrer do trabalho propomo-nos responder às seguintes questões de pesquisa: a) que estratégias de indeterminação de sentido são mais frequentemente usadas nestas conversas? b) que elementos do contexto e do cotexto permitem a delimitação do sentido do item lexical em determinada conversa? c) como funcionam, no corpus, as estratégias de indeterminação de sentido e de que forma elas contribuem para sustentar determinado tipo de relação interpessoal? Para responder a estas questões de pesquisa, das 22 gravações de conversas telefônicas de atores sociais envolvidos com tráfico de armas e drogas, sequestro e extorsão, fornecidas pela Coordenadoria de Segurança e Inteligência do Ministério Público do Rio de Janeiro, selecionamos 10 conversas, em função da sua qualidade sonora, para serem transcritas e para proceder à análise qualitativa do uso da polissemia e da vagueza lexical. A partir das discussões teóricas e das análises desenvolvidas, concluímos que a polissemia representa a estratégia de indeterminação de sentido mais frequente no corpus desta pesquisa e que a mesma pode ser entendida como um processo de mesclagem conceptual, que sofre influências sociais e culturais: é a dinamicidade do pensamento e da linguagem que geram a polissemia. Concluímos também que a vagueza lexical é utilizada, no corpus, como um recurso linguístico para referência a assuntos ilícitos. Os itens lexicais analisados instanciam esquemas mentais abstratos que têm seus sentidos realizados a partir de pistas linguísticas e extralinguísticas que apontam para um processo interacional que pode ser entendido como um enquadre de transações comerciais (tráfico de drogas) / The main objective of this research is to study strategies of indeterminacy of meaning in a corpus of intercepted telephone conversations by social actors involved with the trafficking of drugs and weapons, with kidnapping and extortion. We elected Cognitive Linguistics as the area in which this research should be developed, as we understand the process of meaning production as a cognitive process, dependent on the context. Within Cognitive Linguistics, we adopted the principles and assumptions guiding the Theory of Idealized Cognitive Models (TMCI) and Conceptual Blending Theory, based principally on studies by Lakoff (1987), Fauconnier (1997) and Fauconnier and Turner (2002). Throughout the paper our purpose is to answer the following research questions: a) what strategies for the indeterminacy of meaning are most often used in these conversations? b) what elements of context and co-text (the immediate grammatical context ) trigger the instantiation of the meaning of a lexical item in a particular conversation? c) how do the strategies of indetermination of meaning operate , in the corpus, and how do they contribute to the creation of a particular kind of interpersonal relationship? In order to answer these questions, from the 22 recordings provided by the Coordinator of Intelligence and Security of the Public Ministry of Rio de Janeiro, we selected 10 conversations, on the basis of their sound quality. We further transcribed them and submitted them to qualitative analysis, investigating the use of lexical polysemy and vagueness. From the theoretical discussions and analyzes undertaken, we conclude that polysemy represents the strategy of indeterminacy of meaning that is most often used in the corpus and that it can be understood as a process of conceptual blending, under the influence of social and cultural factors: it is the association between the use of language and the real dynamics of thought and language that generate polysemy. We also conclude that lexical vagueness is used as a language resource to refer to illicit affairs. The lexical items studied instantiate abstract mental schemas whose meanings are triggered by the use of particular linguistic and extralinguistic cues, within the domain, or frame, of a commercial transaction (drug trafficking)