This thesis investigates the effect of incorporating various information visualisation techniques and non-speech sounds (i.e. auditory icons and earcons) in email browsing. This empirical work consisted of three experimental phases. The first experimental phase aimed at finding out the most usable visualisation techniques for presenting email information. This experiment involved the development of two experimental email visualisation approaches which were called LinearVis and MatrixVis. These approaches visualised email messages based on a dateline together with various types of email information such as the time and the senders. The findings of this experiment were used as a basis for the development of a further email visualisation approach which was called LinearVis II. This novel approach presented email data based on multi-coordinated views. The usability of messages retrieval in this approach was investigated and compared to a typical email client in the second experimental phase. Users were required to retrieve email messages in the two experiments with the provided relevant information such as the subject, status and priority. The third experimental phase aimed at exploring the usability of retrieving email messages by using other type of email data, particularly email threads. This experiment investigated the synergic use of graphical representations with non-speech sounds (Multimodal Metaphors), graphical representations and textual display to present email threads and to communicate contextual information about email threads. The findings of this empirical study demonstrated that there is a high potential for using information visualisation techniques and non-speech sounds (i.e. auditory icons and earcons) to improve the usability of email message retrieval. Furthermore, the thesis concludes with a set of empirically derived guidelines for the use of information visualisation techniques and non-speech sound to improve email browsing. / Taibah University in Medina and the Ministry of Higher Education in Saudi Arabia.

Le but de cette dissertation est de développer une théorie manifestationaliste du contexte. Cet objectif sera atteint en deux étapes. Premièrement, nous essaierons de spécifier le rôle explicatif du contexte dans l'interprétation de l'énoncé en développant une notion de « force du contexte » et un modèle de « contribution contextuelle ». Deuxièmement, nous allons essayer de montrer comment la force du contexte peut être rendue manifeste par les connecteurs du discours. La thèse comprend deux parties. La première partie est composée de trois chapitres. Le premier chapitre établit principalement un cadre conceptuel dérivé d'une analyse des entrées de dictionnaire pour le contexte afin de capturer notre notion intuitive de contexte. Il y a quatre composantes conceptuelles, « situation », « texte (quelque chose de parlé ou d'écrit) », « connexion », « signification », qui sont indispensables à la compréhension de la notion. La connectivité du contexte, enracinée dans la notion de « connexion », est la base conceptuelle de la notion de « force contextuelle ». Le deuxième chapitre est consacré aux spécifications de certaines conceptions et distinctions fondamentales : la définition du « discours », la distinction entre « phrase » et « énoncé », et la notion de « signification du locuteur » de Paul Grice. Le troisième chapitre est une critique détaillée de deux grandes théories du contexte. La première théorie, adaptée aux indexicaux, commence avec le travail pionnier d'Arthur W. Burks et de Yehoshua Bar-Hillel sur la signification indexicale et aboutit à l'approche bien développée du contexte dans la théorie des indexicaux de Kaplan. La seconde, grâce à Robert Stalnaker, prend le contexte comme le savoir couramment présupposé entre interlocuteurs dans une conversation, ou selon les propres termes de Stalnaker, « terrain d'entente ». La deuxième partie comprend deux chapitres. Dans le premier chapitre, nous clarifions d'abord la différence entre les approches de Kaplanian et de Stalnakerian et les nôtres : les premiers fondent leurs théories sur le concept intuitif de « contexte-comme-situation », à savoir que le contexte est une situation où un explanandum a lieu ; les nôtres ont l'intention de fonder une théorie du contexte sur le concept intuitif de « contexte-en-utilisation ». Grâce au concept de « contexte-en-utilisation », nous sommes donc intéressés par : ∂. La force (pas le contenu) du contexte. ß. La manifestation (pas la représentation) du contexte. / The aim of this dissertation is to develop a manifestationalist theory of context. This aim will be achieved by two steps. First, we will try to give a new specification of the explanatory role of context in utterance interpretation by developing a notion of the “force of context” and an account of “contextual contribution”. Second, we will try to show how the force of context can be made manifest by discourse connectives. The dissertation includes two parts. The first part is comprised of three chapters. The first chapter mainly establishes a conceptual framework derived from an analysis of dictionary entries for “context” to capture our intuitive notion of it. There are four conceptual components, “situation”, “text (something spoken or written)”, “connection”, “meaning”, which are indispensable for an understanding of the notion. The connectedness of context, rooted in the very notion of “connection”, is the conceptual basis of the notion of “context force”. The second chapter is dedicated to specifications of some related fundamental conceptions and distinctions: the definition of “discourse”, the distinction between “sentence” and “utterance”, and the Gricean notion of “speaker meaning”. The third chapter is a detailed review of two major theories of context. The first, tailoring context to indexicals, begins with the pioneering work of Arthur W. Burks and Yehoshua Bar-Hillel on indexical meaning and culminates in the well-developed approach to context in Kaplan’s theory of indexicals. The second, due to Robert Stalnaker, takes context as the knowledge commonly presupposed between interlocutors in a conversation, or in Stalnaker’s own terms, “common ground”. The second part includes two chapter. In the first chapter, we primarily clarify the difference between Kaplan and Stalnaker’s approaches and ours: the former base their theories on the intuitive concept of context-as-situation, namely that the context is a situation where some explanandum occurs; the latter intends to base a theory of context on the intuitive concept of context-in-use. Stemming from the concept of context-in-use, we are thus interested in: ∂. The force (not the content) of context. ß. The manifestation (not the representation) of context.

Philosophiae Doctor - PhD / This research study investigates optimization of IRS to individual information needs in order of relevance. The research addressed development of algorithms that optimize the ranking of documents retrieved from IRS. In this thesis, we present two aspects of context-awareness in IR. Firstly, the design of context of information. The context of a query determines retrieved information relevance. Thus, executing the same query in diverse contexts often leads to diverse result rankings. Secondly, the relevant context aspects should be incorporated in a way that supports the knowledge domain representing users’ interests. In this thesis, the use of evolutionary algorithms is incorporated to improve the effectiveness of IRS. A context-based information retrieval system is developed whose retrieval effectiveness is evaluated using precision and recall metrics. The results demonstrate how to use attributes from user interaction behaviour to improve the IR effectiveness

The current study examined how repetitive exposure of an opponent’s stroke preferences on video affected the integration of contextual priors and kinematic information during anticipation in skilled boxers. We performed an experimental ingroup-design with a temporal-occlusion video-based anticipation task with repeated measures where 19 male skilled boxers (M = 22.95 age, SD = 4.26) classified as A boxers in Sweden participated in the study. The test represented three different stroke combinations divided into four tests and two exposure videos. Each test included 22 occluded clips divided into two blocks and each block contained six high-probability strokes, three moderate-probability strokes and two low- probability strokes. The participants were informed to answer which stroke they anticipated and how sure they were of their answer after each clip. Retrospective verbal reports were answered regarding what information the participants used to anticipate the strokes in the preceding test. The purpose of the exposure videos was to manipulate the participants’ to-be- anticipated action in favor of the opponent’s stroke preferences both when the opponent acted and did not act accordingly. The result indicated that participants learned kinematic information about the opponent by observing the opponent on video rather than learning about the opponent’s stroke preferences. Future research is needed to fully understand how contextual priors integrate with kinematic information in boxing. / Föreliggande studie undersökte hur repetitiv exponering av en motståndares slagpreferenser på video påverkade integrationen av kontextuell förhandsinformation och kinematisk information under antecipering hos skickliga boxare. Vi utförde en experimentell inomgruppsdesign med en videobaserad temporal-ocklusion anticiperingsuppgift med upprepade mätningar där 19 skickliga manliga boxare (M = 22.95 ålder, SD = 4.26) klassade som A-boxare i Sverige deltog i studien. Testet representerade tre olika slagkombinationer uppdelade i fyra tester och två exponerings videor. Varje test inkluderade 22 ockluderade klipp uppdelade i två block där varje block innehöll sex slag med hög sannolikhet, tre slag med måttlig sannolikhet och två slag med låg sannolikhet. Deltagarna informerades om att svara vilket slag de anteciperade och hur säkra de var på sitt svar efter varje klipp. Retrospektiva verbala rapporter besvarades angående vilken information deltagarna använde för att antecipera slagen i det föregående testen. Syftet med exponerings videorna var att manipulera deltagarnas antecipering till förmån för motståndarens slag preferenser både när motståndaren agerade och inte agerade därefter. Resultatet visade att deltagarna lärde sig kinematisk information om motståndaren genom att observera motståndaren på video snarare än att lära sig om motståndarens slag preferenser. Framtida forskning behövs för att öka förståelsen för hur kontextuell förhandsinformation integreras med kinematisk information i boxning.

Debugging is one of the most time-consuming activities in software development. Several fault localization techniques have been proposed in the last years, aiming to reduce development costs. A promising approach, called Spectrum-based Fault localization (SFL), consists of techniques that provide a list of suspicious program elements (e.g., statements, basic blocks, methods) more likely to be faulty. Developers should inspect a suspiciousness list to search for faults. However, these fault localization techniques are not yet used in practice. These techniques are based on assumptions about the developer\'s behavior when inspecting such lists that may not hold in practice. A developer is supposed to inspect an SFL list from the most to the least suspicious program elements (e.g., statements) until reaching the faulty one. This assumption leads to some implications: the techniques are assessed only by the position of a bug in a list; a bug is deemed as found when the faulty element is reached. SFL techniques should pinpoint the faulty program elements among the first picks to be useful in practice. Most techniques use ranking metrics to assign suspiciousness values to program elements executed by the tests. These ranking metrics have presented similar modest results, which indicates the need for different strategies to improve the effectiveness of SFL. Moreover, most techniques use only control-flow spectra due to the high execution costs associated with other spectra, such as data-flow. Also, little research has investigated the use of SFL techniques by practitioners. Understanding how developers use SFL may help to clarify the theoretical assumptions about their behavior, which in turn can collaborate with the proposal of techniques more feasible for practical use. Therefore, user studies are a valuable tool for the development of the area. The goal of this thesis research was to propose strategies to improve spectrum-based fault localization, focusing on its practical use. This thesis presents the following contributions. First, we investigate strategies to provide contextual information for SFL. These strategies helped to reduce the amount of code to be inspected until reaching the faults. Second, we carried out a user study to understand how developers use SFL in practice. The results show that developers can benefit from SFL to locate bugs. Third, we explore the use of data-flow spectrum for SFL. Data-flow spectrum singles out faults significantly better than control-flow spectrum, improving the fault localization effectiveness. / Depuração é uma das atividades mais custosas durante o desenvolvimento de programas. Diversas técnicas de localização de defeitos têm sido propostas nos últimos anos com o objetivo de reduzir custos de desenvolvimento. Uma abordagem promissora, chamada Localização de Defeitos baseada em Espectro (LDE), é formada por técnicas que fornecem listas contendo elementos de código (comandos, blocos básicos, métodos) mais suspeitos de conter defeitos. Desenvolvedores deveriam inspecionar uma lista de suspeição para procurar por defeitos. No entanto, essas técnicas de localização de defeitos ainda não são usadas na prática. Essas técnicas baseiam-se em suposições sobre o comportamento de desenvolvedores durante a inspeção de tais listas que podem não ocorrer na prática. Um desenvolvedor supostamente inspeciona uma lista de LDE a partir do elemento mais suspeito para o menos suspeito até atingir o elemento defeituoso. Essa suposição leva a algumas implicações: as técnicas são avaliadas somente pela posição dos defeitos nas listas; um defeito é considerado como encontrado quando o elemento defeituoso é atingido. Técnicas de LDE deveriam posicionar os elementos de código defeituosos entre as primeiras posições para serem úteis na prática. A maioria das técnicas usa métricas de ranqueamento para atribuir valores de suspeição aos elementos executados pelos testes. Essas métricas de ranqueamento têm apresentado resultados semelhantes, o que indica a necessidade de estratégias diferentes para melhorar a eficácia de LDE. Além disso, a maioria das técnicas usa somente espectros de fluxo de controle devido ao alto custo de execução associado a outros espectros, tais como fluxo de dados. Também, poucas pesquisas têm investigado o uso de técnicas de LDE por programadores. Entender como desenvolvedores usam LDE pode ajudar a esclarecer as suposições teóricas sobre seu comportamento, o que por sua vez pode para colaborar para a proposição de técnicas mais viáveis para uso prático. Portanto, estudos com usuários são importantes para o desenvolvimento da área. O objetivo desta pesquisa de doutorado foi propor estratégias para melhorar a localização de defeitos baseada em espectro focando em seu uso prático. Esta tese apresenta as seguintes contribuições originais. Primeiro, nós investigamos estratégias para fornecer informação de contexto para LDE. Essas estratégias ajudaram a reduzir quantidade de código a ser inspecionado até atingir os defeitos. Segundo, nós realizamos um estudo com usuários para entender como desenvolvedores usam LDE na prática. Os resultados mostram que desenvolvedores podem beneficiar-se de LDE para localizar defeitos. Terceiro, nós exploramos o uso de espectros de fluxo de dados para LDE. Mostramos que o espectro de fluxo de dados seleciona defeitos significamente melhor que espectro de fluxo de controle, aumentando a eficácia de localização de defeitos.

Disertacijoje nagrinėjamas mokslo publikacijų automatinio klasifikavimo uždavinys. Šis uždavinys sprendžiamas taikant tikimybinius diskriminantinės analizės metodus. Pagrindinis darbo tikslas - sukurti konstruktyvius klasifikavimo metodus, kurie leistų atsižvelgti į mokslo publikacijų tekstų specifiką. Disertaciją sudaro įvadas, trys pagrindiniai skyriai, rezultatų apibendrinimas, naudotos literatūros ir autoriaus publikacijų disertacijos tema sąrašai ir vienas priedas. Įvadiniame skyriuje aptariama tiriamoji problema, darbo aktualumas, aprašomas tyrimų objektas, formuluojamas pagrindinis darbo tikslas bei uždaviniai, aprašoma tyrimų metodika, darbo mokslinis naujumas, pasiektų rezultatų praktinė reikšmė, ginamieji teiginiai. Įvado pabaigoje pristatomos disertacijos tema autoriaus paskelbtos publikacijos ir pranešimai konferencijose bei disertacijos struktūra. Pirmajame skyriuje matematiškai apibrėžtas ir detalizuotas sprendžiamas uždavinys, pateikta analitinė kitų autorių darbų apžvalga. Pasirinkti ir išanalizuoti keli populiarūs klasifikavimo algoritmai, kurie eksperimentinėje darbo dalyje lyginti su autoriaus pasiūlytaisiais. Antrajame skyriuje sudarytas mokslo terminijos pasiskirstymo tekstuose tikimybinis modelis, išskirti atskiri atvejai, galiojant įvestoms prielaidoms apie terminų tarpusavio sąryšių formas, pasiūlytos modelio identifikavimo procedūros bei suformuluoti konstruktyvūs mokslo publikacijų klasifikavimo algoritmai. Trečiajame skyriuje pateikti pagrindiniai... [toliau žr. visą tekstą] / The dissertation considers the problem of automatic classification of scientific publications. The problem is addressed by using probabilistic methods of the discriminant analysis. The main goal of the dissertation is to create constructive classification methods that would allow to take into consideration specificity of scientific publication text. The dissertation consists of Introduction, 3 chapters, Conclusions, References, list of author's publications, and one Appendix. The introduction reveals the investigated problem, importance of the thesis and the object of research and describes the purpose and tasks of the paper, research methodology, scientific novelty, the practical significance of results examined in the paper and defended statements. The introduction ends in presenting the author’s publications on the subject of the defended dissertation, offering the material of made presentations in conferences and defining the structure of the dissertation. Chapter 1 presents a detailed mathematical formulation of the considered problem, reviews scientific papers on the subject, and analyses a few popular classification algorithms that in Chapter 3 are compared to the ones proposed in this paper. Chapter 2 develops the probabilistic model for scientific terminology distribution over texts, discusses special cases of the model under specific assumptions on forms of terminology relations, suggests the model identification procedures, and formulates constructive scientific... [to full text]

The dissertation considers the problem of automatic classification of scientific publications. The problem is addressed by using probabilistic methods of the discriminant analysis. The main goal of the dissertation is to create constructive classification methods that would allow to take into consideration specificity of scientific publication text. The dissertation consists of Introduction, 3 chapters, Conclusions, References, list of author's publications, and one Appendix. The introduction reveals the investigated problem, importance of the thesis and the object of research and describes the purpose and tasks of the paper, research methodology, scientific novelty, the practical significance of results examined in the paper and defended statements. The introduction ends in presenting the author’s publications on the subject of the defended dissertation, offering the material of made presentations in conferences and defining the structure of the dissertation. Chapter 1 presents a detailed mathematical formulation of the considered problem, reviews scientific papers on the subject, and analyses a few popular classification algorithms that in Chapter 3 are compared to the ones proposed in this paper. Chapter 2 develops the probabilistic model for scientific terminology distribution over texts, discusses special cases of the model under specific assumptions on forms of terminology relations, suggests the model identification procedures, and formulates constructive scientific... [to full text] / Disertacijoje nagrinėjamas mokslo publikacijų automatinio klasifikavimo uždavinys. Šis uždavinys sprendžiamas taikant tikimybinius diskriminantinės analizės metodus. Pagrindinis darbo tikslas - sukurti konstruktyvius klasifikavimo metodus, kurie leistų atsižvelgti į mokslo publikacijų tekstų specifiką. Disertaciją sudaro įvadas, trys pagrindiniai skyriai, rezultatų apibendrinimas, naudotos literatūros ir autoriaus publikacijų disertacijos tema sąrašai ir vienas priedas. Įvadiniame skyriuje aptariama tiriamoji problema, darbo aktualumas, aprašomas tyrimų objektas, formuluojamas pagrindinis darbo tikslas bei uždaviniai, aprašoma tyrimų metodika, darbo mokslinis naujumas, pasiektų rezultatų praktinė reikšmė, ginamieji teiginiai. Įvado pabaigoje pristatomos disertacijos tema autoriaus paskelbtos publikacijos ir pranešimai konferencijose bei disertacijos struktūra. Pirmajame skyriuje matematiškai apibrėžtas ir detalizuotas sprendžiamas uždavinys, pateikta analitinė kitų autorių darbų apžvalga. Pasirinkti ir išanalizuoti keli populiarūs klasifikavimo algoritmai, kurie eksperimentinėje darbo dalyje lyginti su autoriaus pasiūlytaisiais. Antrajame skyriuje sudarytas mokslo terminijos pasiskirstymo tekstuose tikimybinis modelis, išskirti atskiri atvejai, galiojant įvestoms prielaidoms apie terminų tarpusavio sąryšių formas, pasiūlytos modelio identifikavimo procedūros bei suformuluoti konstruktyvūs mokslo publikacijų klasifikavimo algoritmai. Trečiajame skyriuje pateikti pagrindiniai... [toliau žr. visą tekstą]

Personal informatics systems help people collect and reflect on behavioral information to better understand their own behavior. Because most systems only show one type of behavioral information, finding factors that affect one’s behavior is difficult. Supporting exploration of multiple types of contextual and behavioral information in a single interface may help. To explore this, I developed prototypes of IMPACT, which supports reflection on physical activity and multiple types of contextual information. I conducted field studies of the prototypes, which showed that such a system could increase people’s awareness of opportunities for physical activity. However, several limitations affected the usage and value of these prototypes. To improve support for such systems, I conducted a series of interviews and field studies. First, I interviewed people about their experiences using personal informatics systems resulting in the Stage-Based Model of Personal Informatics Systems, which describes the different stages that systems need to support, and a list of problems that people experience in each of the stages. Second, I identified the kinds of questions people ask about their personal data and found that the importance of these questions differed between two phases: Discovery and Maintenance. Third, I evaluated different visualization features to improve support for reflection on multiple kinds of data. Finally, based on this evaluation, I developed a system called Innertube to help people reflect on multiple kinds of data in a single interface using a visualization integration approach that makes it easier to build such tools compared to the more common data integration approach.

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Currently, the use of the Web in the workplace has provided new business models, reduced communication cost and agility in business processes. However, some side effects also arise, since it is estimated that 30-40% of employees taken improperly use of this technology. Among the improper activities are online shopping, games playing and access to pornography sites. Besides exposing the organization s network to computer virus, such behavior causes around of 54 billion dollars annually in lost productivity. From literature, we know the most widely used preventive approach to address this problem is the use of Internet Use Policies (PUI), that corresponds to specification guidelines for employers in determining how the Internet should be used in the workplace. Despite its widespread use, the application of PUI presents difficulties in relation to compliance with the specified guidelines and these guidelines have been applied directly on Internet access filters through Access Control Policies (PCA). By applying PCA, the granularity is a key factor to ensure the web use control, claiming by contextual attributes manipulation that offer fine granularity. However, fine granularity increases the cost of PCA management, mainly because the dynamic changing of web user needs. This work proposes a management model for prevents Internet bad usage in the workplace by using context-based PCAs combined to a police continuous management framework to prevent the PCAs become obsolete. To facilitate the translation of needs to PCAs a software were developed to allow administrators without specific technical knowledge to continuous manage fine-grained PCAs. A case study has developed to validate the applicability of the model in a production environment. The result was the enhancement of a wireless network usage in an educational public institution. / Atualmente, a utilização da Web no ambiente de trabalho tem proporcionado novos modelos de negócio, redução de custo com comunicação e agilidade nos processos empresariais. No entanto, a adoção desse recurso por parte das empresas não trouxe apenas benefícios, uma vez que se estima que 30 a 40% dos empregados utilizam de forma indevida essa tecnologia. Dentre as atividades indevidas mais praticadas encontram-se as compras on-line, jogos de poker e acessos a sites de pornografia. Tal comportamento, além de expor a rede da organização à vírus, gera um prejuízo estimado em 54 bilhões de dólares anualmente em perdas de produtividade. Observa-se na literatura, que a abordagem preventiva mais utilizada para tratar este problema consiste no emprego de Políticas de Utilização da Internet (PUI). Tal estratégia trata-se da especificação de diretrizes por parte dos empregadores determinando como a Internet deve ser utilizada no ambiente de trabalho. Apesar de sua larga utilização, o emprego de PUI apresenta dificuldades em relação ao cumprimento das diretrizes especificadas. Para contornar as dificuldades, pesquisadores tem aplicado tais diretrizes diretamente em filtros de acesso à Internet, através de Políticas de Controle de Acesso (PCA). Ao aplicar PCAs, a granularidade é um fator determinante para potencializar a utilização da Web. Visto que, considerando níveis extremos, tanto permissividade quanto restritividade ocasionam a má utilização da Web. Neste contexto é relevante explorar PCAs baseadas em listas, perfis e atributos contextuais, sendo que as baseadas em atributos contextuais apresentaram granularidade mais fina. Entretanto, na mesma proporção que se afina a granularidade, aumenta-se o custo no processo de elaboração das políticas. Além disto, a alta dinamicidade na disponibilização de recursos na Web, com o passar do tempo, pode tornar obsoletas as PCAs, mesmo se especificadas com granularidade fina, possibilitando novamente a utilização indevida da Web. Devido a esses fatores, incrementa-se a complexidade em conceber uma medida preventiva baseada em PCAs. Todavia, agregando os aspectos eficazes das PUIs, esta dissertação propõe um Modelo de Gestão para Prevenção da Má Utilização da Web que utiliza PCAs sensíveis à atributos contextuais. Tal modelo objetiva evitar que as PCAs tornem-se obsoletas ao aplicar um gerenciamento contínuo dessas políticas. Além disso, busca-se reduzir o ônus da elaboração e gestão das PCAs ao propor um software para transpor as necessidades dos gestores para PCAs sensíveis ao contexto, de modo que administradores sem conhecimentos técnicos específicos gerenciem de forma contínua PCAs baseadas em atributos contextuais. Um estudo de caso em uma instituição pública, cuja atividade fim trata-se do ensino superior, comprovou a aplicabilidade do modelo no ambiente de produção. Obteve-se como resultado a potencialização dos acessos à rede Wireless dessa instituição.

This work presents a boarding on the use of contextual information in a model of access control to electronic patient record (EPR). The EPR registers information on the health of the patient and the assistance given it, and has legal, secret and scientific character, being able to also include administrative and financial contents related the carried through procedures or treatments. In summary, can be said that the EPR keeps to the documents on the state of health and the cares received for an individual throughout its life. However, the availability of clinical information in computer networks raises questionings on the privacy of the patients and the integrity and confidentiality of the data. The access control is a point key to keep such requirements. The main objective in the development of this modelof access control is to provide different forms of access to information in a hospital environment, propitiating the adequacy with the pertinent legislation. To boarding proposal in this work allows to the application of politics and more specific rules of access, adding more functionality to the systems of access control. The focus of quarrel of this work deals with the use of medical information in the scope of the University Hospital of Santa Maria, and aims at to the integration of the model with modules in development in the data processing center of the institution. / Este trabalho apresenta uma abordagem sobre a utilização de informações contextuais em um modelo de controle de acesso a informações de prontuários eletrônicos de paciente (PEP). O PEP registra informações sobre a saúde do paciente e a assistência a ele prestada, e tem caráter legal, sigiloso e científico, podendo incluir também conteúdos administrativos e financeiros relacionados a procedimentos ou tratamentos realizados. Resumidamente, pode-se dizer que o PEP guarda os documentos sobre o estado de saúde e os cuidados recebidos por um indivíduo ao longo da sua vida. Entretanto, a disponibilização de informações clínicas em redes de computadores levanta questionamentos sobre a privacidade dos pacientes e a integridade e confidencialidade dos dados. O controle de acesso é um ponto chave para manter tais requisitos. O principal objetivo no desenvolvimento deste modelo de controle de acesso é prover diferentes formas de acesso a informações em um ambiente hospitalar, propiciando a adequação com a legislação pertinente. A abordagem proposta neste trabalho permite a aplicação de políticas e regras de acesso mais específicas, agregando mais funcionalidade aos sistemas de controle de acesso. O foco de discussão desta dissertação trata da utilização de informações médicas no âmbito do Hospital Universitário de Santa Maria, e visa à integração do modelo com módulos em desenvolvimento no centro de processamento de dados da instituição.