L'expertise internationale joue un rôle important dans la mise à l’agenda d’enjeux environnementaux globaux. Ces évaluations sont souvent contestées, en particulier là où les faits et les valeurs sont fortement imbriqués. Cette thèse examine le cas du Groupe d'experts intergouvernemental sur l'évolution du climat (GIEC), une des organisations d’experts les plus contestées. Elle s'intéresse plus généralement à comment ces organisations maintiennent leur autorité, en croisant les apports théoriques des études des sciences et des techniques et de la sociologie des organisations internationales. Un argument central est que le GIEC, en partie à cause de l'univers controversé dans lequel il évolue, est devenu une bureaucratie internationale. La thèse identifie quatre arrangements institutionnels sur lesquels l'organisation s'est appuyée pour maintenir son autorité. Premièrement, elle s'est efforcée de maintenir une représentation équilibrée des États, principalement entre pays développés et pays en développement. Deuxièmement, il a mis en place des mécanismes de gouvernance qui permettent aux gouvernements de jouer un rôle dans le processus d'évaluation, encourageant la “reappropriation” de ses conclusions. Troisièmement, il a procéduralisé le processus d'évaluation pour formaliser le rôle de ses différentes parties et protéger l'organisation contre les critiques. Quatrièmement, il est plus attentif à la gestion de la communication. Ces arrangements sont régulièrement renégociés dans le contexte de nouveaux défis et controverses. Au-delà du GIEC, ils offrent de nouvelles perspectives pour observer l'imbrication de l'autorité politique et épistémique. / In the last decades, international expertise has been essential to put global environmental problems on the international agenda. These assessments are often contested, especially on issues where facts and values are profoundly entangled. This thesis investigates the case of the Intergovernmental Panel on Climate Change (IPCC), one of the most authoritative, albeit contested expert organisation. It is more generally interested in how these organisations construct and maintain their authority, drawing on insights from Science and Technology Studies and sociological approaches to international organisations. A central argument is that, partly as a result of the controversial universe in which it has evolved, the IPCC has grown into an international bureaucracy. The thesis identifies four institutional arrangements on which the organisation has relied to maintain its authority. First, it has strived for a balanced representation of all nations, and in particular between developed and developing countries. Second, it has put in place governing mechanisms that allow governments to play a central role in the assessment process, encouraging the ‘ownership’ of its conclusions. Third, it has increasingly proceduralised the assessment, to formalise the role of its different parts and protect the organisation against criticism. Four, it has been more attentive to the management of the information displayed about its work. These arrangements are regularly renegotiated in the context of new challenges and controversies. Beyond the IPCC, they provide relevant lenses to observe the intertwining of political and epistemic authority at the international level.

Les médias sociaux ont changé notre manière de communiquer entre individus, au sein des organisations et des communautés. La disponibilité de ces données sociales ouvre de nouvelles opportunités pour comprendre et influencer le comportement des utilisateurs. De ce fait, la fouille des médias sociaux connait un intérêt croissant dans divers milieux scientifiques et économiques. Dans cette thèse, nous nous intéressons spécifiquement aux utilisateurs de ces réseaux et cherchons à les caractériser selon deux axes : (i) leur expertise et leur réputation et (ii) les sentiments qu’ils expriment.De manière classique, les données sociales sont souvent fouillées selon leur structure en réseau. Cependant, le contenu textuel des messages échangés peut faire émerger des connaissances complémentaires qui ne peuvent être connues via la seule analyse de la structure. Jusqu’à récemment, la majorité des travaux concernant l’analyse du contenu textuel était proposée pour l’Anglais. L’originalité de cette thèse est de développer des méthodes et des ressources basées sur le contenu pour la fouille des réseaux sociaux pour la langue Française.Dans le premier axe, nous proposons d'abord d’identifier l'expertise des utilisateurs. Pour cela, nous avons utilisé des forums qui recrutent des experts en santé pour apprendre des modèles de classification qui servent à identifier les messages postés par les experts dans n’importe quel autre forum. Nous démontrons que les modèles appris sur des forums appropriés peuvent être utilisés efficacement sur d’autres forums. Puis, dans un second temps, nous nous intéressons à la réputation des utilisateurs dans ces forums. L’idée est de rechercher les expressions de confiance et de méfiance exprimées dans les messages, de rechercher les destinataires de ces messages et d’utiliser ces informations pour en déduire la réputation des utilisateurs. Nous proposons une nouvelle mesure de réputation qui permet de pondérer le score de chaque réponse selon la réputation de son auteur. Des évaluations automatiques et manuelles ont démontré l’efficacité de l’approche.Dans le deuxième axe, nous nous sommes focalisés sur l’extraction de sentiments (polarité et émotion). Pour cela, dans un premier temps, nous avons commencé par construire un lexique de sentiments et d’émotions pour le Français que nous appelons FEEL (French Expanded Emotion Lexicon). Ce lexique est construit de manière semi-automatique en traduisant et en étendant son homologue Anglais NRC EmoLex. Nous avons ensuite comparé FEEL avec les lexiques Français de la littérature sur des benchmarks de référence. Les résultats ont montré que FEEL permet d’améliorer la classification des textes Français selon leurs polarités et émotions. Dans un deuxième temps, nous avons proposé d’évaluer de manière assez exhaustive différentes méthodes et ressources pour la classification de sentiments en Français. Les expérimentations menées ont permis de déterminer les caractéristiques utiles dans la classification de sentiments pour différents types de textes. Les systèmes appris se sont montrés particulièrement efficaces sur des benchmarks de référence. De manière générale, ces travaux ont ouvert des perspectives prometteuses sur diverses tâches d’analyse des réseaux sociaux pour la langue française incluant: (i) combiner plusieurs sources pour transférer la connaissance sur les utilisateurs des réseaux sociaux; (ii) la fouille des réseaux sociaux en utilisant les images, les vidéos, les géolocalisations, etc. et (iii) l'analyse multilingues de sentiment. / Social Media has changed the way we communicate between individuals, within organizations and communities. The availability of these social data opens new opportunities to understand and influence the user behavior. Therefore, Social Media Mining is experiencing a growing interest in various scientific and economic circles. In this thesis, we are specifically interested in the users of these networks whom we try to characterize in two ways: (i) their expertise and their reputations and (ii) the sentiments they express.Conventionally, social data is often mined according to its network structure. However, the textual content of the exchanged messages may reveal additional knowledge that can not be known through the analysis of the structure. Until recently, the majority of work done for the analysis of the textual content was proposed for English. The originality of this thesis is to develop methods and resources based on the textual content of the messages for French Social Media Mining.In the first axis, we initially suggest to predict the user expertise. For this, we used forums that recruit health experts to learn classification models that serve to identify messages posted by experts in any other health forum. We demonstrate that models learned on appropriate forums can be used effectively on other forums. Then, in a second step, we focus on the user reputation in these forums. The idea is to seek expressions of trust and distrust expressed in the textual content of the exchanged messages, to search the recipients of these messages and use this information to deduce users' reputation. We propose a new reputation measure that weighs the score of each response by the reputation of its author. Automatic and manual evaluations have demonstrated the effectiveness of the proposed approach.In the second axis, we focus on the extraction of sentiments (emotions and polarity). For this, we started by building a French lexicon of sentiments and emotions that we call FEEL (French Expanded Emotions Lexicon). This lexicon is built semi-automatically by translating and expanding its English counterpart NRC EmoLex. We then compare FEEL with existing French lexicons from literature on reference benchmarks. The results show that FEEL improves the classification of French texts according to their polarities and emotions. Finally, we propose to evaluate different features, methods and resources for the classification of sentiments in French. The conducted experiments have identified useful features and methods in the classification of sentiments for different types of texts. The learned systems have been particularly efficient on reference benchmarks.Generally, this work opens promising perspectives on various analytical tasks of Social Media Mining including: (i) combining multiple sources in mining Social Media users; (ii) multi-modal Social Media Mining using not just text but also image, videos, location, etc. and (iii) multilingual sentiment analysis.

La pratique de l’examen psychologique de l’enfant et de l’adolescent alléguant, au stade de l’enquête préliminaire (dans le cadre de la procédure pénale), des violences sexuelles subies constitue le point de départ de cette étude. Elle pose la question du positionnement à la fois procédural, clinique et méthodologique de l’expert psychologue mais également celle de la crédibilité. Laissant de côté d’éventuels facteurs d’influence et ce que les allégations ne seraient pas ou insuffisamment par rapport à un discours traumatique-type, nous nous sommes intéressés à ce qu’elles seraient, pourraient révéler, illustreraient du mode de fonctionnement psychique du sujet alléguant. A partir d’une revue de la littérature, nous avons envisagé une clinique de l’allégation reposant sur un modèle pluridimensionnel qui intègre tout à la fois les dimensions cognitivo-développementale, psychogénétique, tendancielle, interrelationnelle, événementielle, procédurale, syndromique, sémiologique et intrapsychique. Ce modèle, plaçant le processus d’allégation (renvoyant ou non à une expérience traumatique subie dans le réel) au coeur d’une analyse multidimensionnelle et plurifactorielle, envisage celle-ci sur un registre dynamique incluant les apports validés dans chacun des champs auxquels les dimensions ci-dessus renvoient. A partir d’examens psychologiques réels et d’une méthodologie hypothético-déductive, nous avons développé un outil appelé table d’analyse séquentielle psycho-victimologique visant à permettre un appariement d’éléments appartenant à des dimensions distinctes, à mettre en évidence des hypothèses et à les tester. / The practice of psychological examination - in the context of a criminal procedure - of the child or teenager who claims to have been a victim of sexual violence, is at the start of the present study. It raises the question of the standpoint – procedural, clinical and methodological – of the expert psychologist, as well as that of credibility. Leaving aside possible factors of influence and what the allegations might not be or be insufficiently in relation to a typical traumatic talk, we have focused our attention on what they might be or might reveal and illustrate about the psychological functioning of the author of the claims. Starting from a survey of the available literature, we have envisaged a clinical view of the allegation, based on a multidimensional model which encompasses all at once the cognitive-developmental, psycho-genetic, underlying, interrelational, circumstantial, procedural, syndromic, semiological and intrapsychic dimensions. Such model, which places the allegation process (referring or not to a traumatic experience undergone in reality) at the heart of a multidimensional and multifactorial analysis, considers the said analysis on a dynamic register, including the acquisitions validated in each of the fields referred to by the abovementioned dimensions. Starting from real psychological examinations and using a hypothetic-deductive approach, we have developed a tool which we call a sequential psycho-victimological analysis table, aiming at allowing the matching of elements belonging to distinct dimensions, to highlight and test hypotheses.

O presente trabalho visa a uma discussão crítica acerca das relações entre filosofia e mídia. Para tanto, valemo-nos das teorizações foucaultianas acerca da problemática da governamentalidade, por meio de um procedimento analítico inspirado na obra Arqueologia do saber. Partiu-se de um primeiro mapeamento de enunciados de diferentes naturezas que se dedicaram a debater desdobramentos da popularização da filosofia e a difundir produções culturais alegadamente filosóficas. Em seguida, tendo uma revista brasileira de jornalismo cultural CULT Revista Brasileira de Cultura como plataforma empírica de investigação, mapearam-se todos os artigos e entrevistas realizados por e com filósofos ou com alguma formação em filosofia num período de quase 17 anos, de 1997, ano de fundação da revista, até 2013, totalizando 186 fascículos. A análise debruçou-se sobre os diversos modos de abordagem temática, teórica e metodológica presentes nos artigos da referida revista, optando por categorizar os escritos segundo suas estratégias discursivas proeminentes. Inventariamos profissões dos autores, correlações narrativas, temas gerais, teorizações, os objetos privilegiados e conceitos-chave. Deste modo, procuramos problematizar determinados jogos de governo de si e dos outros, articulados pela assiduidade, adensamento e desaparecimento de certos tipos de estratégias, auscultando também o que seria o papel relegado ao filósofo como pensador e/ou intelectual público ante seu presente em suma, a função pública do filósofo na mídia. Nossa hipótese de trabalho apostou numa possível conversão da prática filosófica em uma expertise da conduta humana, por meio de sua aliança com práticas de cunho estético e psicopedagógico, findando por participar de tal modo no rol das estratégias contemporâneas de governo de si e dos outros. / This paper aims at a critical discussion on the relations between philosophy and the media. For this purpose, we make use of Foucault\'s theories about the problematics of governmentality through an analytical procedure inspired by the Archaeology of knowledge. We started from an initial mapping of different kinds of statements who were dedicated to discussing about the unfoldings of the popularization of philosophy, and to spreading allegedly philosophical cultural productions. Having a Brazilian magazine of cultural journalism CULT Revista Brasileira de Cultura as our empirical research platform, we have mapped all articles and interviews by and with philosophers or by authors with some philosophical background within a period of almost 17 years, from 1997, the magazine\'s founding year, until 2013, totaling 186 issues. The analysis has scrutinized the diverse modes of thematical, theoretical and methodological approaches within the magazine articles, by opting to categorize them according to their prominent discursive strategies. We inventoried authors\' institutional affiliations, the styles of the narratives, the general themes, the theories, the privileged objects and key concepts. Therefore, we have tried to problematize certain games of government of the self and others, articulated by attendance, density and disappearance of certain types of strategies, also observing what role would be relegated to the philosopher as a thinker and/or a public intellectual at his present in short, the philosophers public role on the media. Our working hypothesis bets on a possible conversion of the philosophical practice into an expertise of the human conduct, by its alliance with aesthetic and psychopedagogical practices, participating in such a way in the list of contemporary strategies of government of the self and others

Effective management of knowledge assets is key to surviving in today's competitive business environment. This is particularly true for large organisations, where employees have difficulties identifying where or with whom the knowledge lies. Expertise is one of the most important knowledge assets and largely resides in the heads of employees. Many attempts have been made to help locate employees with the right expertise; however, the existing systems (often referred to as expertise finding systems) carry several flaws. In organisations, there are several potential sources where expertise evidence might be found. These sources have been used by the existing approaches to profile employees' expertise. Unfortunately, there has been limited research showing whether these sources contain useful evidence of expertise. Moreover, the majority of existing approaches have not been designed to integrate with the organisations' work practices; nor have they investigated the socio-ethical challenges associated with the adoption of such systems. Therefore, there is a need for expert finding systems that utilise useful sources of expertise and integrate into existing work practices. Through industry involvement, this research has explored and validated email content as a source for expertise profiling. This thesis provides an overview of the traditional and current approaches to expertise finding. The development and implementation of the EKE (Email Knowledge Extraction) system which tries to overcome the aforementioned challenges is presented. EKE has been evaluated by end-users from both industry and academia. The evaluation results suggest that EKE is a useful system that encourages participation, and that in many cases may assist in the management of knowledge within organisations.

RAMOS, Danilo. Fatores emocionais durante uma escuta musical afetam a percepção temporal de músicos e não músicos? 2008, 268 p. Tese (Doutorado). Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto. Universidade de São Paulo, Ribeirão Preto, 2008. Esta pesquisa teve como objetivo verificar o papel das emoções desencadeadas pela música na percepção temporal de músicos e não músicos. Quatro experimentos foram realizados: no Experimento I, músicos e não músicos realizaram tarefas de associações emocionais a trechos musicais de 36 segundos de duração, pertencentes ao repertório erudito ocidental. A tarefa consistia em escutar cada trecho musical e associá-lo às categorias emocionais Alegria, Serenidade, Tristeza, Medo ou Raiva. Os resultados mostraram que a maioria dos trechos musicais desencadeou uma única emoção específica nos ouvintes; além disso, as associações emocionais dos músicos foram semelhantes às associações emocionais dos não músicos para a maioria dos trechos musicais apresentados. No Experimento II, músicos e não músicos realizaram tarefas de associação temporal aos trechos musicais mais representativos de cada emoção, utilizados no Experimento I. Assim, os trechos musicais eram apresentados e os participantes deveriam associar cada um deles a durações de 16, 18, 20, 22 ou 24 segundos. Os resultados mostraram que, para o grupo Músicos, os três trechos musicais associados à Tristeza foram subestimados em relação às suas durações reais; nenhuma outra categoria emocional apresentou mais do que um trecho musical sendo subestimado ou superestimado em relação a suas durações reais, para ambos os grupos. Pesquisas recentes em Psicologia da Música têm mostrado duas propriedades estruturais como sendo moduladoras da percepção de emoções específicas durante uma escuta musical: o modo (organização das notas dentro de uma escala musical) e o andamento (número de batidas por minuto). Assim, no Experimento III, músicos e não músicos realizaram tarefas de associações emocionais a composições musicais construídas em sete modos (Jônio, Dórico, Frígio, Lídio, Mixolídio, Eólio e Lócrio) e três andamentos (adágio, moderato e presto). O procedimento foi o mesmo utilizado no Experimento I. Os resultados mostraram que o modo musical modulou a valência afetiva desencadeada pelos trechos musicais: trechos musicais apresentados em modos maiores obtiveram índices positivos de valência afetiva e trechos musicais apresentados em modos menores obtiveram índices negativos de valência afetiva; além disso, o andamento musical modulou o arousal desencadeado pelos trechos musicais: quanto mais rápido o andamento do trecho musical, maiores os níveis de arousal desencadeados e vice-versa. No Experimento IV, músicos e não músicos realizaram tarefas de associação temporal aos trechos musicais modais utilizados no Experimento III. O procedimento foi o mesmo utilizado no Experimento II. Os resultados mostraram que manipulações, principalmente no arousal, afetaram a percepção temporal dos ouvintes: para ambos os grupos, foram encontradas subestimações temporais para trechos musicais desencadeadores de baixos índices de arousal; além disso, para o grupo Não Músicos, foram encontradas superestimações temporais para trechos musicais desencadeadores de altos índices de arousal. Estes resultados mostraram que, no caso dos músicos, a percepção temporal foi afetada por atmosferas emocionais relacionadas à Tristeza; no caso dos Não Músicos, a percepção temporal foi afetada por fatores relacionados ao nível do arousal dos eventos musicais apreciados. / RAMOS, Danilo. Do emotional factors during music listening tasks affect time perception of musicians and nonmusicians? 2008, 268 pages. Thesis (PhD). Faculty of Philosophy, Sciences and Letters of Ribeirão Preto. University of São Paulo, Ribeirão Preto, 2008. This study aimed to verify the role of emotions triggered by music on time perception of musicians and nonmusicians. Four experiments were conducted: In Experiment I, musicians and nonmusicians performed emotional association tasks for musical excerpts of 36 seconds duration belonging to the Western classic repertoire. The tasks required to listen to each musical excerpt and to associate it with emotional categories: Joy, Serenity, Sadness, or Fear/Anger. The results showed that most musical excerpts triggered a specific single emotion in listeners; moreover, the emotional associations of musicians were similar to the emotional associations of nonmusicians for most musical excerpts presented. In Experiment II, musicians and nonmusicians performed temporal association tasks for the three most representative excerpts of each emotion used in Experiment I. Thus, the participants had to associate each of such musical excerpts with the following durations: 16, 18, 20, 22 or 24 seconds. The results showed that for the musicians, the three musical excerpts associated with Sadness were underestimated in relation to their real time; moreover, no other emotional category was associated with more than one musical excerpt whether being underestimated or overestimated, regarding their real time, for both groups. Recent researches in Psychology of Music have shown two structural properties as the modulators of specific emotions perceived during a music listening task: the mode (the organization of the notes in a musical scale) and tempo (the number of beats per minute). Thus, in Experiment III, musicians and nonmusicians carried out emotional association tasks with musical compositions constructed in seven modes (Ionian, Dorian, Phrygian, Lydian, Mixolydian, Aeolian, and Locrian) and three tempi (adagio, moderato, and presto). The procedure was the same used in Experiment I. The results showed that the musical mode modulated the affective valence triggered by the excerpts: musical excerpts based on major modes obtained positive affective valence indexes and musical excerpts based on minor modes obtained negative affective valence indexes; moreover, the musical tempo modulated the arousal triggered by the excerpts: the faster the tempo of the musical excerpts, the higher the arousal levels and vice versa, for both groups. In Experiment IV, musicians and nonmusicians performed temporal association tasks for those modal musical excerpts used in Experiment III. The procedure was the same used in Experiment II. The results showed that manipulations concerning arousal affected the time perception of the listeners: time underestimations due to low arousal excerpts were found for both groups; moreover, time underestimations due to high arousal excerpts were found only for nonmusicians. These results showed that in the case of musicians, time perception was affected by emotional atmospheres related to Sadness; in the case of nonmusicians, time perception was affected by factors related to the level of arousal of music events appreciated.

Cette thèse entreprend l’étude de l’éducation à la sexualité à l’école et sur les forums internet au prisme d’une sociologie de l’expertise. L’expertise consiste en une activité de conseil face à un problème. Ce travail observe les situations dans lesquelles se développe l’éducation à la sexualité, les équipements et les expériences qui y sont mobilisés, et les dynamiques interactionnelles dans lesquelles elle se déploie. L’analyse de l’éducation à la sexualité à l’école, principalement menée par des infirmières scolaires et l’étude de forum internet offrent une variabilité de situation d’expertise. Dans la première, l’éducation est institutionnalisée et reste extrêmement cadrée, tandis que dans la seconde, elle reste ouverte au débat et aborde des questions qui ne le sont pas à l’école. D’autre part, il s’agit également d’envisager que ces deux formes d’éducations constituent deux modalités de construction du sujet. L’éducation à la sexualité des adolescents circule entre plusieurs registres. L’adolescence est envisagé comme un moment de danger, de prise de risque et l’éducation à la sexualité met l’accent sur les responsabilités inhérentes à l’entrée dans la sexualité : il s’agit de se protéger des maladies mais aussi des expériences néfastes, d’être un individu responsable. L’étude laisse apparaître un nouveau régime normatif dans lequel l’éducation ne s’appuie plus sur des dimensions coercitives et une relation asymétrique mais laisse place à une relation égalitaire, faite de dialogue et de confidence, qui s’appuie plus sur des disciplines intériorisées / The present thesis focuses on the study of the sexual education within educational structures and online chat rooms as seen through the prism of the sociological study of expertise. The notion of expertise is understood as a counseling activity when dealing with a given problem. This work focuses on the development of sexual education within specific circumstances, as well as the tools and experiences used and the dynamics at play within its development.Through the analysis of sexual education at school, which is largely conducted by school nurses, and the study of online forums, a number of situations involving expertise can be observed. Within the first of these abovementioned settings, the education is instutitionalized and maintains fixed parameters ; in the second setting however it remains up to debate, including on many subjects that aren't be covered at school. Also, one must bear in mind that both these educational construction in the subject. Teenage sexual education spans several registers. Teenage years are seen as a dangerous time, when undue risks are taken and focus is maintained on the responsibilities implied within the introuction to sexuality. It is about protecting oneself from diseases as well as negative experiences and to become a responsible individual. A new regulatory regime is shown within this study, whereby education no longer relies on coercitive dimensions and an asymetrical relationship, but gives way to an egalitarian relationship which is based on dialogue and the sharing of confidential information, based on inward-looking disciplines

Cette thèse explore les rouages d’un collectif de travail à l’œuvre sur un chantier de fouille archéologique situé à Ormesson (Seine-et-Marne, France), un site paléolithique jonché de milliers d’éclats de silex et de fragments d’os. Chaque année, une vingtaine de personnes provenant d’horizons variés partage une expérience quotidienne en travaillant autour de l’exploration du site tout en vivant ensemble pendant plus d’un mois. Je fais l’hypothèse que les rôles distribués par le chef de chantier orchestrant les opérations ne sont que les limites poreuses de l’engagement réel, variable et fragile de chaque fouilleur. En développant un protocole méthodologique dédié à l’observation participante ainsi qu’à la captation d’images filmiques de journées entières de travail, je décortique ce huis clos scientifique à travers la façon dont Isabelle (chercheure spécialisée dans le traitement osseux) et Mélodie (néophyte et passionnée d’histoire) transmettent et s’approprient le passé matériel qu’elles fouillent. Mon objectif est alors moins d’analyser le fonctionnement d’un collectif éphémère que de caractériser les fondements de la singularité d’individus au travail ainsi que les nuances de l’expertise scientifique en archéologie, et ce, à travers différents phénomènes que j’analyserai : les modalités perceptives de traces matérielles fragiles, les valeurs collectives en jeu, les affects que les uns et les autres apprennent à jauger et les représentations du passé les plus scénarisées. Le travail de fouille suppose un continuel aller-retour avec un passé en cours d’exploration et des expériences de travail au présent, un processus pratique et singulier qu’Isabelle et Mélodie me permettent de suivre à travers elles. / This thesis examines the inner workings of a group of researchers collaborating on an archeological excavation in Ormesson (Seine-et-Marne, France), on a paleolithic site strewn with thousands of flint pieces and bone fragments. Every year, around twenty people from various backgrounds share the day-to-day experience of working on the exploration of the site, as they live together for more than a month. I argue that the roles distributed by the site manager who organizes the operation are only the porous boundaries of each digger’s real, variable, fragile engagement. By developing a methodological protocol that involves participant observation and the filming of entire days of work, I dissect this closed scientific world through the way in which Isabelle (a researcher specializing in bone treatment) and Mélodie (a novice with a passion for history) transmit and appropriate the material past they excavate. My aim is therefore not so much to analyze the operation of a temporary group, but rather to characterize the foundations of the singularity of individuals at work, as well as the subtle differences in scientific expertise in archeology, though analysis of various phenomena: the modalities of perceiving fragile material traces, the group values at play, the affects that everyone learns to gauge, the most deliberated representations of the past. Excavation work implies continually shifting back and forth between a past under exploration and work experiences in the present, a practical and singular process that Isabelle and Mélodie allow me to follow through them.

L’exercice des pratiques non conventionnelles est confronté, à présent, à différentes difficultés dans la recherche de légitimité, notamment celle professionnelle. En particulier, les praticiens exerçant dans ce domaine créent une activité d'indépendant sur des savoirs peu légitimes du point de vue des standards. Cette population de praticiens étudiés recouvre plusieurs segments : médecins en soins de santé non-conventionnels, thérapeutes sans diplômes de médecine et chamans. L'étude est faite en comparant ces trois segments en France et en Tunisie et en montrant l’importance de l'apprentissage et la construction de l'expertise sur un marché faiblement régulé dans des contextes sociétaux différents. Dans ce cadre, ce premier courant théorique est complété par le courant théorique s’intéressant, en sciences de gestion, au mode d’apprentissage et de construction de l’expertise en entrepreneuriat. Cette construction de l’expertise suppose un apprentissage des connaissances déclaratives et procédurales, celles-ci combinées à travers l’apprentissage par l’expérience, viennent agrandir et modifier les connaissances issues de la formation académique, par la théorisation de la pratique. Ainsi, grâce à une démarche qualitative menée en France et en Tunisie, la compréhension de la dynamique de construction de l’expertise chez différents praticiens, dont le parcours se construit diversement en fonction de leur appartenance et attributs professionnels, nous a permis de déterminer les types de légitimités acquises. / The exercise of non-conventional practices is now confronted with various difficulties in the search of legitimacy, particularly the professional one.The practitioners, practicing in this field, create an independent activity on a slight illegitimate knowledge, from a standard perspective. This studied population of practitioners cover many segments: non-conventional doctors, therapists without medical qualifications, and shamans. This research study is done by comparing above mentioned three segments in France and Tunisia, also by showing the importance of learning and constructing the expertise in a low- regulated market in different societal contexts.In this context, this first theoretical insight is completed which interest, in the science of management, in the mode of learning and construction of expertise in entrepreneurship.The construction of expertise supposes a learning of the declarative and procedural knowledge. This procedural knowledge, combined through the learning by the experience, enlarge and modify the knowledge resulting from the academic formation, by the theorization of the practice.Thus, through a qualitative research conducted in France and Tunisia, understanding dynamics of construction of expertise of different practitioners, whose course is constructed differently according to their attributes and professional affiliations, allowed us to determine the types of legitimacy acquired.

This thesis explores the professional practice of two highly accomplished expert teachers, ‘masters’ of classical ballet, with the aim of providing an understanding of their expertise. A qualitative case study methodology was used to illuminate the masters’ knowledge acquisition and teaching practices. Data collection comprised interviews with the masters and a sample of their students, and teaching observations of the masters at work. A metaphoric conceptual framework of a three-act ballet performance has been used to present the thesis. This dance-related metaphor was chosen: firstly, because it keeps the ballet context in focus; secondly, because it allows for the leading roles to be those of the masters, and their students, and; thirdly because it provides a fitting way to highlight key themes that emerged from the data analysis. Furthermore, just as an entire three-act ballet needs to be experienced in order to fully understand its story, so too, all three acts of the thesis ‘performance’ must be read in order to appreciate the complexity and inter-connected nature of the masters’ practice. Part One (The Programme) provides the foundation work of the thesis (introduction, literature review, methodology, and methods). Part Two includes The Performance, with the Prologue presenting biographic narratives for both masters and each of the three acts revealing key dimensions of the masters’ practice. Act One explores their knowledge acquisition, professional philosophies and beliefs. Act Two explores their professional orientations. Act Three illuminates their expertise in action, within the class and rehearsal environment. Important themes include the recognition that, for the masters, learning and teaching develop over a lifetime and are inspired by an immense passion and dedication for ballet and its teaching. Also, a master brings to the art- form his/her own individuality, and creativity, and actively contributes to ballet’s historical continuum through his/her professional legacy of practice. While some of the findings support aspects already described in the literature about expertise, the use of a domain-specific case study establishes this support, and illuminates a new perspective with much needed evidence. A Grand Finale concludes the study, with the development of a prototypical view of the professional practice of a classical ballet master. Such a prototype has the potential to inform researchers of exemplary practice in other art forms, and more importantly, to highlight the essential characteristics of exemplary ballet masters.