La gestion des connaissances, fortement facilitée par l’introduction des TIC, est perçue au niveau de l’organisation comme un moyen de gérer au mieux son capital intellectuel. La connaissance étant devenue à la fois un support et un facteur important du changement organisationnel, l’intérêt des TIC se situe dans la possibilité de générer une importante base de connaissances interactive et facilement accessible et exploitable par les utilisateurs. Dans cette thèse, nous proposons d’étudier l’adoption de la gestion des connaissances comme une nouvelle approche pour la gestion des organisations en Algérie. Nous orientons notre problématique vers la création de valeur organisationnelle, qui a pour conséquence l’amélioration de la performance. La spécificité de notre objet de recherche est abordée à travers une méthodologie qualitative. L’originalité de ce travail se trouve dans la prise en compte de deux niveaux d’analyse : le niveau global et le niveau des organisations. Pour étudier le niveau global, nous nous inscrivons dans une démarche de compréhension de l’application d’une stratégie de gestion des connaissances à un projet de gouvernance électronique en Algérie. Le niveau des organisations est étudié à travers une étude de cas multiple destinée à rechercher des régularités, des divergences et des convergences entre les éléments des différents cas étudiés. L’objectif de cette recherche, qui s’inscrit dans un cadre d’analyse multidimensionnel et reste essentiellement exploratoire, est de comprendre etd’expliquer les relations qualitatives qui régissent le phénomène que nous étudions. / Knowledge management, which is very simplified by the IT introduction, is seen in the organisation as a means for the best management of the intellectual capital. As knowledge has become both a support and an important factor of the organisational change, the IT’s interest lies in the capacity of generating an important interactive base of knowledge which is easy to access and to exploit. In this thesis, we study the adoption of knowledge management as a new approach for the management of organisations in Algeria. Our problematic is turned towards the organisational value creation, which results in performance improvement. The specificity of our research’s object is dealt through a qualitative methodology. The originality of this work is to take into account two analysis levels: the global level and the organisations level. To study the global level, we lead an approach to understanding the application of a strategy of knowledge management in an electronic governance project in Algeria. We study the organisations level through a multi-case study, to look for regularities, divergences and convergences between the elements of the different studied cases. The objective of this research, which is essentially exploratory, lies within the framework multidimensional analysis to understand and explain the qualitative relations which characterize the phenomenon we are studying.

Le présent document obéit à un plan strict inhérent à tous les manuscrits de thèsepassée en Validation des Acquis de l’Expérience (VAE). Après un CV détaillé ledocument présente tout d’abord un retour réflexif sur le parcours professionnel c'està-dire, une synthèse sur les taches effectuées d’un travail de type projet vers uneimplication de plus en plus forte vers un travail de recherche à proprement parlé. Aprèsce retour réflexif qui permet d’avoir une vue d’ensemble de la progression du parcours,une synthèse est proposée, non pas de la totalité des travaux, mais de trois domainesbien précis et représentatifs du parcours de recherche. Ce choix s’est fait en cherchantun fil d’Ariane qui est tout simplement la nature chimique de la céramique étudiée ;dans le présent document il s’agit de carbures et plus précisément de SiC, TiC, ZrC,HfC. Tout d’abord le travail sur les céramiques monolithiques pour les applicationsnucléaires est abordé puis, les applications spatiales avec la mise au point deprotections contre l’oxydation à partir de poudres revêtues enfin, le document s’achèvepar des travaux d’infiltration de céramiques à partir d’un matériau intermétallique oucomment il est possible de faire des céramiques ultra réfractaires à basse température.Ces travaux étant originaux ils ont fait l’objet de brevets et de publications qui serontabordés dans la troisième partie. / This document obeys a strict plan inherent in all PhD manuscripts passed in Validationof the Assets of Experiment (VAE). After a detailed resume this document first of all,presents a reflexive return on the career i.e., from a work of type project towards anincreasingly strong implication to a research task. After this reflexive return whichmakes it possible to have an overall picture of the progression of the course, asynthesis is proposed, not of total work, but of three fields quite precise andrepresentative of the course of research. This choice was done by seeking a wire ofARIANE which is the chemical nature of the studied ceramics; in this document it isabout carbides and more precisely about SiC, TiC, ZrC, HfC. First of all monolithicceramics for the nuclear applications is approached then, the space applications withthe elaborating of protections against oxidation made by core shell powders finally, thedocument is completed by ceramics infiltrations from an intermetallic material or howit is possible to make ultra refractory ceramics at low temperature. As these works areoriginal they were the object of patents and publications which will be approached inthe third part.

La dynamique d’hypercompétition qui sévit dans les grandes économies met toutes les entreprises dans un contexte de sélection compétitive. L’obtention du Graal de cette nouvelle économie, en l’occurrence l’avantage concurrentiel, dépend principalement de la faculté des entités créatrices de valeur à accroître leur capacité d’innovation et leur agilité stratégique. L’information et/ou la connaissance renseignant sur l’évolution de l’environnement des entreprises s’affirment comme les matières premières stimulant la créativité et l’agilité stratégique au niveau organisationnel. D’où un besoin accru d’optimiser la gestion de l’information et la production de connaissances. Les TIC apparaissent dans ce contexte comme un support d’optimisation de l’évolution de données brutes gravitant autour des environnements stratégiques en connaissances (cycle de l’intelligence économique). Leur caractère de levier d’innovation réside en effet dans leur capacité à industrialiser la production de connaissances. Cependant, la subjectivité de la capacité d’absorption de nouvelles informations et la dimension tacite de la connaissance font que les technologies informatiques soient incapables d’automatiser parfaitement le cycle de l’intelligence économique. / The dynamic of hypercompetition that exists in the major economies puts all businesses in a context of competitive selection. Obtaining the Grail of this new economy, namely the competitive advantage, mainly depends on the ability of companies to increase their capacity for innovation and their strategic agility. The information and / or the knowledge inquiring about the evolution of the business environment appear as raw materials stimulating creativity and strategic agility of the firms. Whence an increased need to optimize the management of information and the production of knowledge. ICT are in this context as a support for optimizing the evolution of raw data into knowledge (cycle of business intelligence). Their character of innovation lever lies indeed in their ability to industrialize the production of knowledge. However, the subjectivity of the absorption capacity of news informations and the tacit dimension of knowledge explain that computer technologies are unable to fully automate the cycle of economic intelligence.

Nowadays, more and more industrial assets are continuously monitored and generate vast amount of event logs and sensor data. Data Mining is the field concerned with the exploration and exploitation of these data. Despite the fact that data mining has been researched for decades, the event log data are still underexploited in most data mining workflows although they could provide valuable insights on the asset behavior as they represent the internal processes of an asset. However, exploitation of event log data is challenging, mainly as: 1) event labels are not consistent across manufacturers, 2) assets report vast amount of data from which only a small part may be relevant, 3) textual event logs and numerical sensor data are usually processed by methods dedicated respectively to textual data or sensor data, methods combining both types of data are still missing, 4) industrial data are rarely labelled, i.e. there is no indication on the actual performance of the asset and it has to be derived from other sources, 5) the meaning of an event may vary depending on the events send after or before.Concretely, this thesis is concerned with the conception and validation of an integrated data processing framework for scalable performance assessment of industrial asset portfolios. This framework is composed of several advanced methodologies facilitating exploitation of both event logs and time series sensor data: 1) an ontology model describing photovoltaic (the validation domain) event system allowing the integration of heterogeneous event generated by various manufacturers; 2) a novel and computationally scalable methodology enabling automatic calculation of event relevancy score without any prior knowledge; 3) a semantically enriched multi-level pattern mining methodology enabling data exploration and hypothesis building across heterogeneous assets; 4) an advanced workflow extracting performance profiles by combining textual event logs and numerical sensor values; 5) a scalable methodology allowing rapid annotation of new asset runs with a known performance label only based on the event logs data.The framework has been exhaustively validated on real-world data from PV plants, provided by our industrial partner 3E. However, the framework has been designed to be domain agnostic and can be adapted to other industrial assets reporting event logs and sensor data. / Doctorat en Sciences de l'ingénieur et technologie / info:eu-repo/semantics/nonPublished

A sociedade atual é também conhecida como Sociedade da Informação, pois o acesso às informações e ao conhecimento está disponível de maneira rápida através das Tecnologias de Informação e Comunicação (TIC), como computador, Internet e telefone celular. Assim, tem sido necessário elaborar novas maneiras de pensar e conviver com essas tecnologias. Para o desenvolvimento socioeconômico das nações é importante formar uma sociedade crítica, reflexo do processo educacional adotado; dessa maneira, é preciso se apropriar das TIC para obter práticas de ensino mais criativas e flexíveis. Para que essa integração gere resultados satisfatórios é preciso a união de diversos fatores como a infraestrutura disponível na escola, o domínio dos professores sobre a utilização nas atividades de ensino-aprendizagem, a integração no projeto político-pedagógico, a implementação de políticas públicas na área educacional pelo governo etc. Dessa forma, o levantamento de dados estatísticos sobre a adoção das TIC nos processos educacionais se faz necessário. Pesquisas amostrais são muito utilizadas com o intuito de conhecer determinada característica sobre uma população. O tamanho das amostras costuma ser planejado para a obtenção de dados para grandes áreas, no entanto, vem crescendo o desejo de se obter informações em níveis mais desagregados, onde o tamanho da amostra é pequeno para a produção de estimativas com precisão aceitável, sem aumentar o tamanho amostral. Em vista disso, a metodologia de estimação em pequenas áreas tem sido desenvolvida de forma a produzir estimativas com precisão adequada para as características de interesse, considerando a distribuição de probabilidade trazida no desenho amostral ou a utilização de modelos que emprestam informações para áreas semelhantes. O objetivo desta dissertação é a obtenção dessas estimativas para a proporção de escolas em que os professores usam a Internet em atividades de ensino-aprendizagem com os alunos para cada Unidade Federativa do Brasil, utilizando dados reais provenientes da pesquisa TIC Educação, produzida pelo CGI.br, e do Censo Escolar, produzido pelo INEP. Obtemos as estimativas por diferentes abordagens, tanto direto da amostra quanto através da construção de modelos de regressão logística, e as comparamos através da estimativa do erro quadrático médio e da proporção de acertos, através da matriz de confusão por validação leave-one-out. Para a consolidação dos resultados obtidos nos dados reais, fazemos um estudo de simulação de dados. O modelo de efeitos aleatórios é considerado como o que apresentou os melhores resultados. / The current society is also known as the Information Society because access to information and knowledge is available through Information and Communication Technologies (ICT) such as computer, Internet and mobile phone. Thus, new ways of thinking and living with these technologies have become necessary. For the socio-economic development of nations it is important to create a critical society, reection of adopted educational process; In that way, appropriating ICT should be necessary to obtain more creative and exible teaching practices. To obtain satisfactory performance it needs the union of several factors such as the infrastructure available in schools, the teacher\'s knowledge about how to adopt ICT on practical activities, the ICT integration on the political pedagogical project, the implementation of public policies on the educational sector etc. In this manner, collect statistical data about ICT adoption on teaching practices is necessary. Sample surveys are widely used in order to understand certain characteristics of a population. The sample sizes is often designed to obtain results for large areas, nevertheless, the desire to obtain these results for more disaggregated areas, where the sample size is small to produce reliable estimates, are increasing without increasing the sample size. Small area estimation methodology has been developed to produce reliable estimates about some desired characteristics considering the probability distribution introduced on the sample design or considering models to lend information to resembling domains. Our purpose is to obtain estimates to the proportion of schools wherein teachers use the Internet to teaching-learning activities with their students for each Federative Unit of Brazil using real data from ICT in Education Survey, conducted by CGI.br, and Scholar Census, conducted by INEP. We obtain these estimates from dierent aproaches both by direct estimator and by logistic regression models and we compare them under the mean squared error and the proportion of success using confusion matrix by leave-one-out cross-validation. To consolidate these results we do a simulation study. The logistic random eects model is considered the best approach.

Alicerçada no pressuposto da inter-relação entre os campos da comunicação e do feminismo, esta proposta pretende fornecer subsídios ao movimento de mulheres e feminista, comprovando que as Tecnologias da Informação e Comunicação (TIC) -- que têm na internet a sua maior expressão -- não são um fim, mas um instrumento para a transformação social. Com a revolução das TIC, o avanço do trabalho pela equidade das relações sociais de gênero depara-se com o desafio da mudança de mentalidade. Concomitantemente com a revolução tecnológica, ocorrem as revoluções do aprendizado e da expressão pessoal e interpessoal, acarretando outras formas de representação da mulher em função das novas dinâmicas comunicacionais. É pela comunicação a distância que se vislumbra um caminho de reformulação da agenda feminista, com novas estratégias de intervenção política e de atuação. O recorte da pesquisa foca a implementação do uso da internet -- mais especificamente das redes sociais -- para o avanço da luta contra a violência às mulheres, no âmbito doméstico. Considera-se esta cruel realidade como a mais grave expressão das desigualdades de gênero, as quais foram construídas há milênios, colocando a mulher em condição de subordinação ao homem, o que acarreta prejuízos para toda a sociedade. / Based on the assumption of inter-relation between the fields of communication and feminism, this proposal intends to provide subsidies to the women\'s and feminist movement, proving that Information and Communication Technologies (ICT) -- which have in the internet their most significant expression -- are not an end, but rather an instrument for social transformation. With the ICT revolution, the advancement of work for equality in social gender relations faces the challenge of a mentality change. Simultaneously with the technological revolution, the revolutions in the areas of learning and personal and interpersonal expression are occurring, bringing forth new forms of representation of women, made possible by the new communicational dynamics. It is through long-distance communication that it is possible to foresee a path for reformulation of the feminist agenda, with new strategies for political intervention and action. The research focuses on the implementation of the use of the internet for the progression of the specific struggle against violence on women, in the domestic sphere, considering this cruel reality as the gravest expression of gender inequalities, built millennia ago, and which places women in a position of subordination to men, causing damages to society as a whole.

L'objet de cette thèse est de pointer les difficultés rencontrées par le droit de la consommation lorsqu'il est confronté aux déséquilibres nés de l'usage des technologies de l'information, et de proposer des solutions cohérentes juridiquement et rationnelles sur le plan économique. Les terminaux connectés à l'internet deviennent de plus en plus nombreux. Le consommateur est amené à conclure régulièrement des contrats souvent très denses, aux enjeux difficiles à appréhender et presque systématiquement à dimension internationale. La matière de cette thèse est composée de tous les contrats conclus par le biais de l'internet à partir d'un terminal connecté, dont l'objet est une exécution totalement dématérialisée via les technologies de l'information. Ceci constitue l'économie numérique. Par le biais notamment de la règlementation relative aux clauses abusives, cette thèse s'intéressera particulièrement au sort des données à caractère personnel, à la géolocalisation, aux contenus protégés par la propriété intellectuelle et aux nombreuses restrictions d'utilisation dont ils font l'objet. Au travers de cette thèse, les insuffisances des différents corps de règles applicables aux contenus numériques (protection des données à caractère personnel, droit de la propriété intellectuelle, droit de la consommation) seront mises en évidence. Plusieurs propositions et synthèses seront envisagées au sein de cette thèse afin de remédier au mieux aux déséquilibres propres de l'économie numérique. / The aim of this Ph.D. is to highlight the difficulties encountered by Consumer law when it meets the use of information technologies, and to propose operating solutions in Law which might be rational under economy requirements. Connected devices become more and more common. The consumer is frequently asked to conclude very thick contracts, with stakes hard to comprehend and almost consistently with an international overture. The material of this Ph.D. is composed by all the contracts concluded through the internet from a connected device, whose object is a totally dematerialised execution via information technologies. This constitutes the digital economy. Thanks to the unfair terms regulation, this Ph.D. will focus on the becoming of personal data, the geolocation, the contents protected by Intellectual property and all the restrictions of use those contents are subjected to. Among this work, the deficiencies of the different rules applicable to digital contents (personal data protection, Intellectual property, Consumer law) will be emphasized. Many suggestions and reviews will be envisaged into this Ph.D. in order to solve to the best the specific unbalances of the digital economy.

Made available in DSpace on 2016-03-22T17:27:23Z (GMT). No. of bitstreams: 1 Vanessa Doumid Damasceno.pdf: 1132073 bytes, checksum: dadb0c0413e3a559b3988c581224cf86 (MD5) Previous issue date: 2014-06-05 / This research aims to identify, analyze and interpret the voices that constitute the discourse of Basic Education students of the last year of high school, of a private school in the municipality of Pelotas/RS, about the presence of Information and Communication Technologies - ICT for learning. The students were asked by the researcher to position themselves on the presence of ICT in the classroom and in their learning. The theoretical approach that guides the research comes from studies of the Bakhtin Circle about some constitutive phenomena of discursive communication, such as language, enunciation, discourse, dialogism, authorship, as well as cultural studies (Bauman, 2005; Hall, 2004 and Moita Lopes, 2002) and the vygotskian theory of learning. The research participants are ten students: seven girls and three boys. The data were generated through a focal group. To proceed with the dialogic analysis of the students discourses, we start from the methodological proposal by Bakhtin (VOLOCHINOV) (1929/1992) and conduct the incursion on the student s speech of extraverbal elements of the constitution of the statement: chronotope, interlocutors and theme(s), which are inseparable from its verbal materiality. Because of the vast data that involving this research, I selected, as factors to be focused on this study, the aspects related to learning, ICT; student, school and teacher. The data show that ICT in the classroom are not immediately in the center, still it is demonstrated the teacher as a key over of any technological apparatus. The teacher, in the students view, is responsible for leading the process of teaching and learning / Esta pesquisa tem por objetivo identificar, analisar e interpretar as vozes que constituem o discurso de alunos da Educação Básica do último ano do Ensino Médio de uma escola da rede particular do município de Pelotas/RS sobre a presença das Tecnologias da Informação e Comunicação - TIC na aprendizagem. Os discentes foram convidados pela pesquisadora a se posicionarem sobre a presença das TIC na sala de aula e no seu aprendizado. O aporte teórico que orienta a pesquisa vem dos estudos do Círculo de Bakhtin sobre alguns fenômenos constitutivos da comunicação discursiva, como linguagem, enunciado, discurso, dialogismo, autoria, bem como dos estudos culturais (Bauman, 2005; Hall, 2004 e Moita Lopes, 2002) e da teoria vygotskyana de aprendizagem. Os participantes da pesquisa são dez alunos: sete meninas e três meninos. Os dados foram gerados por meio de grupo focal. Para proceder à análise dialógica dos discursos dos alunos, partiu-se da ordem metodológica proposta por Bakhtin (VOLOCHINOV) (1929/1992) e realizou-se a incursão nas falas dos alunos pelos elementos extraverbais da constituição do enunciado: cronotopo, interlocutores e tema(s), os quais são indissociáveis de sua materialidade verbal. Diante do universo de dados que envolve a pesquisa, escolhi, como fatores a serem foco do estudo, os aspectos relacionados com aprendizagem, TIC, aluno, escola e professor. Os dados evidenciam que as TIC, na sala de aula não estão de imediato como centro, demonstra-se ainda o professor como peça fundamental à frente de qualquer aparato tecnológico. O professor, para os alunos, é o responsável por conduzir o processo de ensino e de aprendizagem

Submitted by admin tede (tede@pucgoias.edu.br) on 2017-08-21T13:16:07Z No. of bitstreams: 1 MARIA DAS GRAÇAS FERNANDES TORRES.pdf: 1703336 bytes, checksum: 3c2266c10fe3042ef0433d83c2a585ef (MD5) / Made available in DSpace on 2017-08-21T13:16:07Z (GMT). No. of bitstreams: 1 MARIA DAS GRAÇAS FERNANDES TORRES.pdf: 1703336 bytes, checksum: 3c2266c10fe3042ef0433d83c2a585ef (MD5) Previous issue date: 2017-06-26 / The objective of this study is the analysis the use of social networks as a tool or instrument used by the teacher in his/her role of mediation in the teaching and learning process. Its theoretical foundation relies on the works of Vygostky and Moscovici, in addition to using other authors who contribute to the theme as Araújo (2012), Gabriel (2010), Moran (2013), Sancho (2012) and Peixoto (2019a, 2011, 2016).This is considered a fertile research field and, for this reason, we propose, through this project, to study the use of these social networks in Education taking into account the mediation that can happen with the intentional interventions of the teachers. It is a case study (GODOY, 1995) that relies on qualitative and quantitative methods. The data were collected in the first semester of 2016 in a private higher education institution in Goiânia, in the fashion design course, that uses social networks in an interdisciplinary evaluative work in which the student needs to devise a concept and a collection of clothes that can be posted and evaluated through facebook. Seven teachers involved in a focus group agreed to discuss this interdisciplinary work virtually and also involving a face to face interaction. In addition, 192 participants (among students and former ones) answered an online questionnaire composed of 26 open and closed questions. The questions dealt about the students' experience in presenting the academic papers virtually, their involvement with social networks and the skills and competences acquired from the activity, as well as verifying the participation of the teacher as a mediator in the teaching and learning process. The case study made it possible to analyze the common-sense theories (MOSCOVICI, 2011) collectively constructed from an experience lived by a social group that, in this case, was characterized by the participation of the ones involved with the interdisciplinary work that culminated in a post in the social network facebook. The analysis of the data indicates some conflicts between the students' and teachers' understanding of the pedagogical value of the use of social networks. They are discussed seeking to clarify the main conclusions and also to answer the problem and the objectives of the research. / Esta dissertação tem por objetivo verificar como acontece o uso das redes sociais, enquanto ferramenta ou instrumento que pode ser utilizado pelo professor em seu papel de mediação, no processo de ensino e de aprendizagem. Ela tem como fundamentação teórica as obras de Vygotsky e Moscovici, além de recorrer a outros autores que contribuem para a temática como Araújo (2012), Gabriel (2010), Moran (2013), Peixoto (2019ª, 2011, 2016) e Sancho (2012). Considera-se este um campo fértil para a pesquisa e, por esse motivo, propomos, por meio deste projeto, estudar o uso dessas redes sociais na Educação levando em consideração a mediação que pode acontecer com as intervenções intencionais dos professores. Trata-se de um estudo de caso (GODOY, 1995) que utiliza métodos qualitativos e quantitativos. Os dados foram coletados no primeiro semestre de 2016 em uma IES privada em Goiânia, no curso de moda, que utiliza as redes sociais em um trabalho avaliativo interdisciplinar no qual o aluno precisa criar um conceito e uma coleção de roupas que podem ser postados e avaliados por meio do facebook. Os dados foram coletados mediante a participação de sete professores envolvidos em um grupo focal que concordaram em discutir o trabalho interdisciplinar na modalidade presencial e virtual. Além disso, contou também com a participação de 192 alunos e egressos que responderam on line, a um questionário composto de 26 questões abertas e fechadas. As questões versavam sobre a experiência dos alunos ao apresentar os trabalhos acadêmicos virtualmente, seu envolvimento com as redes sociais e as habilidades e competências adquiridas com a atividade, além de verificarem acerca da participação do professor como mediador no processo de ensino e aprendizagem. O estudo de caso possibilitou analisar as teorias do senso comum (MOSCOVICI, 2011) construídas coletivamente a partir de uma experiência vivida por um grupo social que, neste caso, caracterizou-se pela participação de todos os envolvidos no trabalho interdisciplinar que culminava em uma postagem na rede social facebook. A análise dos dados aponta para alguns conflitos entre a compreensão dos alunos e dos professores sobre o valor pedagógico do uso das redes sociais. Eles são discutidos buscando clarear as principais conclusões e respondendo ao problema e aos objetivos da pesquisa.

Les technologies de l’information et de la communication (TIC) occupent une place importante dans les débats publics sénégalais. En outre, elles semblent être au centre des préoccupations des dirigeants de ce pays, car les espoirs qu’elles suscitent dans le domaine de l’éducation sont assez nombreux. Mais, l’introduction des TIC dans les lycées soulève également des interrogations de la part des chercheurs et des acteurs éducatifs quant à leurs usages. Cette thèse porte sur les pratiques numériques des lycéens. L’objectif que nous poursuivons est de comprendre dans quelle mesure les usages des TIC peuvent leur permettre de s’approprier des savoirs. Ici, comprendre c’est, s’intéresser aux représentations, aux connaissances et aux compétences qui impliquent l’usage des outils informatisés, mais aussi aux sens des usages. La question des usages des TIC par les élèves suscite un intérêt particulier auprès des chercheurs de certaines disciplines, particulièrement ceux de la sociologie des usages, des sciences cognitives et des sciences de l’éducation. Ainsi, nous avons privilégié une approche théorique pluridisciplinaire et une pluralité méthodologique (le questionnaire, l’observation directe et l’entretien d’explicitation) en ayant recours à des outils spécifiques pour recueillir les données (dictaphone, notes, captures d’écrans). L’analyse a permis de voir que ces usagers-apprenants s’approprient les technologies numériques à des fins d’apprentissage et a mis en relief le « versant sombre » de leurs pratiques. Partant des données obtenues nous proposons quelques pistes de réflexion pour une intégration optimale des TIC dans les pratiques d’enseignement et d’apprentissage. / Information and communication technologies (ICTs) are central to Senegalese public debates. Moreover, the leaders of this country view them as very advantageous to education. However, their introduction in high schools raises a lot of questions from both researchers and educators as regards their usage. This study is about digital practices of high school students Our aim is to understand the extent to which the use of ICTs can enable them to acquire knowledge. Understanding in this regard implies looking at the perceptions, knowledge and skills related to the use of computerized tools, but also the meanings of this usage. The use of ICTs by pupils is also of particular interest to researchers in the fields of humanities and social sciences, especially those in the sociology, cognitive sciences and education areas. Thus, in order to better define the subject, this study used a multidisciplinary theoretical approach and a plural methodology (questionnaires, direct observation and interviews) as well as specific tools (voice-recorder, notes and screenshots) to collect data during two field investigations that were conducted in Dakar secondary schools (from March to April 2013 and November to December 2015). The analysis revealed that these learner-users use digital technologies for learning purposes but also highlighted the "dark side" of their practices. On the basis of the data obtained, we also suggest ways in which ICTs can be optimally integrated in teaching and learning practices.