Existing research investigating human judgment and decision making describes patterns of systematic biases in the way people process information and make decisions. Framing effects, for example, demonstrate that logically equivalent alternatives presented in divergent linguistic frames can lead to systematically different choice outcomes; in general, people demonstrate a preference for risk-averse behaviour when information is framed positively and risk-seeking behaviour when information is framed negatively. Similarly, the status quo bias describes a tendency for decision makers to maintain current or previous decisions when confronted with the availability of new options, demonstrating that people possess a predisposition to continue with established behaviour. This research proposes that the goals a decision maker adopts and the hedonic tone of the stimulus being evaluated influence whether framing effects are observed; similarly, the past performance of the status quo and complexity of available options influence whether participants exhibit a preference for the status quo. Using a survey-based experimental methodology, the aforementioned propositions are investigated by systematically manipulating characteristics of decision problems in order to reveal the mechanisms which influence the emergence of framing effects and the status quo bias. The results demonstrate that when positive goals or stimuli are emphasized, usual framing effects are observed; that is, participants demonstrate a preference for risk-averse behaviour in the positive frame and risk-seeking behaviour in the negative frame. Conversely, when negative goals or stimuli are emphasized, participants fail to demonstrate the expected shift in risk-preference. Past performance and complexity of the available alternatives are also shown to influence preference for the status quo; specifically, participants demonstrate greater preference for the status quo when past performance is strong compared to when it is weak, and when the number of available options is low compared to when it is high. The findings of this research improve our understanding of how contextual factors influence shifts in preference and the emergence of decision making biases; moreover, the current research demonstrates the need for future research to consider the influence of situational and contextual factors when investigating decision making in particular and human behaviour in general.

Thesis presents recent relevant studies of cognitive biases and false perceiving of randomness. There is an ongoing general belief that past performance automatically predicts future performance even in the cases when the result is act of randomness. This became inspiration for the main topic of my scientific research. Based on recent relevant literature I study if it is possible to influence people buying valueless information by evoking feeling of loss. Also I am trying to answer question which personal factors stand behind this behaviour. The results shows, that the manipulation with loss had nothing to do with buying valueless information. However it seems that personality factors are connected with this phenomenon to a certain extent. I had identified one factor called 'Irrational Thinking', which partly explains why 71% of the participants were interested in valueless transaction.

The thesis focuses on estimation of household total risk exposure and factors affecting this estimation. The risk is represented with a financial loss of 20k CZK in the next month and with a financial loss of 50k CZK in the next 12 months. Nearly a half of participants in the survey (n=55) estimates the likelihood of this financial shock as being low, however the number of participants with high estimate increases for the next 12 months. The estimate of total risk exposure increases with age, for self-employed and single parents, next with income and assets, however overall wealth decreases the estimate. Significant factors are education, financial behaviour and cognitive abilities which all have a decreasing effect on the estimate. Availability is considered as significant having a positive effect while biased evaluation of risks has a negative effect. Time preferences can play an important role in the estimation of a long-term risk.

Целью работы является исследование повышения эффективности труда сотрудников промышленного предприятия с учетом влияния когнитивных искажений. Для этого был разработан методический подход, в основу которого положен учет когнитивных искажений, включающий в себя классификацию групп рабочих по уровню когнитивных искажений и эффективности труда, а также комплекс мероприятий, направленных на нивелирование влияния когнитивных искажений, что позволит снизить воздействие когнитивных искажений и достигнуть более высоких показателей эффективности труда на промышленном предприятии. / The aim of the work is to study the improvement of the labor efficiency of employees of an industrial enterprise, taking into account the influence of cognitive distortions. For this purpose, a methodical approach was developed, which is based on the account of cognitive distortions, including the classification of groups of workers by the level of cognitive distortions and labor efficiency, as well as a set of measures aimed at leveling the influence of cognitive distortions, which will reduce the impact of cognitive distortions and achieve higher labor efficiency indicators at an industrial enterprise.

Ce manuscrit comporte trois essais qui partagent l’objectif commun d’évaluer l’impact de la confiance en soi sur les décisions des agents économiques à l’aide de la méthode expérimentale. Ce travail se concentre sur trois thèmes relatifs à l’économie comportementale du travail : le travail au noir, la recherche d’emploi et le travail en équipe. Le premier chapitre analyse les biais d’optimisme dans le contexte du travail irrégulier. Ce travail fournit une mesure des biais d’optimisme à travers un processus de décision. Les résultats montrent que les modalités d’annonce du contrôle altèrent la perception du risque : la désignation du nombre d’agents aléatoirement contrôlés tend à encourager l’optimisme des fraudeurs. Le second chapitre étudie comment l’incertitude quant à l’habileté et l’estime que les demandeurs d’emploi ont d’eux-mêmes affectent leurs décisions de recherche. Les résultats montrent qu’en moyenne les agents peu habiles ne modifient pas leur salaire de réserve, alors que les sujets très habiles tendent à diminuer leurs exigences salariales et donc à stopper plus rapidement leur recherche. Cependant, les décisions des agents peu habiles ne sont pas homogènes : les agents peu compétents ont des exigences salariales d’autant plus élevées qu’ils ont une haute estime d’eux-mêmes. Le troisième chapitre vise à évaluer dans quelle mesure l’image que les travailleurs ont d’eux-mêmes conditionne leur choix d’effort lorsqu’ils travaillent en groupe. Les résultats montrent que les agents qui sur évaluent (sous-évaluent) leur habileté exercent plus (moins) d’effort que les sujets qui ont une perception correcte de leurs compétences. Les résultats révèlent également que les individus bénéficient de la sur-confiance de leur partenaire, mais pas de leur propre biais, alors que la sous-confiance détériore le bien-être de tous les membres de l’équipe. / This dissertation contains three essays that estimate the effects of self-confidence on economic agents’ decisions. An experimental approach is used for those contributions. This work is interested in three topics concerning behavioral labor economics: moonlighting, job search and teamwork. The first chapter investigates the existence of optimism biases in the context of irregular work. This essay proposes a measure of optimism biases through a decision process. The results show that the way the monitoring policy is announced deeply affects the perception of the risk at stake: the designation of the number of randomly controlled agents tends to foster the cheats’ optimism. The second chapter studies how the uncertainty on ability and self-esteem of job-seekers affect their search behaviors. The results show that on average the low ability agents’ decisions are not affected by the uncertainty about their ability, whereas the high ability agents tend to decrease their reservation wage and thus to stop their search faster. However, the low ability agents’ decisions are not homogeneous: the higher the worker’s self-esteem is, the higher his reservation wage is. The third chapter aims at estimating how workers’ self-image biases affect effort choices and team production. The results show that the workers who overestimate (underestimate) their ability provide higher (lower) effort levels than the unbiased. The results also reveal that the agents benefit from their partner’s confidence, but not from their own bias. Conversely, the presence of underconfident agents in the team damages the welfare of both teammates.

Comment l'accès au savoir peut-il être impacté par la technologie ? Il suffit d'observer le virage intenté par les outils de communication au début des années 2000 pour se rendre compte : convergence des médias, pratiques participatives et numérisation massive des données. Dans ce contexte, on imagine que l'accès au savoir tend à se démocratiser. En effet, les individus semblent se réapproprier les espaces de vie, en inversant le modèle de transmission top-down, qui va du producteur vers le consommateur, au profit de processus de transfert basés sur l'intelligence collective. Pourtant, on aurait tort de réduire cette réorganisation à un simple renversement du modèle. Car l'intelligence collective est encline à divers biais cognitifs et socio-cognitifs, amenant parfois vers des situations irrationnelles. Autrefois, on s’accommodait de ces mécaniques sociales aux conséquences limitées, aujourd'hui les savoirs numérisés constituent des ensembles massivement communiquant, donnant naissance à de nouvelles voies d'accès et à de nouveaux clivages. Pourquoi ce savoir qui n'a jamais été aussi massif et ouvert, se révèle-t-il si sélectif ? Je propose d'explorer ce paradoxe. L'enregistrement massif et constant de nos traces numériques et l'hyper-connexion des individus, participent à la construction de structures organisationnelles, où se retrouvent numérisées de manière complexe, une partie des dynamiques sociales. En formalisant de la sorte les voies navigables, ces structures organisationnelles façonnent nos trajectoires. Sur cette base, les informaticiens ont mis au point des algorithmes de parcours individualisés, ayant pour objectifs de prédire et de recommander. Ainsi, on propose d'automatiser l'accès au savoir. Se pose alors la question de la gouvernance des individus, dans un contexte où l'intelligence collective est soumise à l'infrastructure : enregistrement des traces, composition des structures organisationnelles et algorithmes de parcours. / How access to knowledge can be impacted by Information Technology? In the earlier 2000s, communication tools caused a significant turn : media convergence, participative practices and massive data. In this way, free access to knowledge might tend to be democratized. People seem to regain spaces, reversing traditional top-down model, going from producer to consumer, for the benefit of an horizontal model based on collective intelligence. However, it should not automatically be assumed that this leads to a simple model reversing. Collective intelligence is subject to cognitive biases, leading to potential irrational situations. Formerly, those social mechanisms had limited consequences. Nowadays, digital knowledge are massive communicating spaces, giving birth to new access paths and new cleavages. Why this massive and open knowledge, is actually so selective? I propose to explore this paradox. Massive and constant tracking of traces and individuals hyper-connection, these two facts help organizational structures design, where social dynamics are digitalized in a complex way. These structures formalize human trajectories. On this basis, computer scientists set up prediction algorithms and recommender engines. This way, knowledge access is automatized. It can then be asked about people governance, in this context of infrastructure submission: recording traces, designing knowledge structure and automating algorithms.

Made available in DSpace on 2016-04-26T20:24:10Z (GMT). No. of bitstreams: 1 Eduardo Jose da Fonseca Costa.pdf: 1263073 bytes, checksum: 5e0088ac0a9fdf2802c5b0844e006375 (MD5) Previous issue date: 2016-02-15 / Impartiality is essential to jurisdiction, and among other things, it guarantees the parties and the maintenance of democracy itself. The procedural law systems currently in force in Brazil need to walk in opposite direction to the path they are actually taking in order for it to be minimally guarded, that is, regarding subjective impartiality specifically. These systems have already been feeding the cognitive bias factors of the adjudicative decision-makers and, therefore, feeding a breach of its systemic and unconscious biases. In this sense, the present work proposes a legislative reform, offering a precautionary model of lege ferenda inspired in algorithmic strategies based on the latest findings of a new discipline increasingly thriving in Anglo-Saxon countries, Israel and Western Europe called Behavioral Law and Economics (resulting from a fusion of law, cognitive psychology and behavioral economics). Hence the reason it is a legal enginnering work. Now, assuming that any decision maker is equipped with a bounded rationality (not to be confused with actual irrationality ), these techniques seek to undo or to isolate the effects of the so-called cognitive biases , which are mere shortcuts predictable and therefore, preventable which the human mind develops in order to make decisions from complex information under situations of uncertainty. Thus, the major cognitive illusions which affect the adjudicative decision-makers (representativeness bias, anchoring-and-adjustment bias, confirmation bias and in-group bias) were studied along with the procedural standards better suited to neutralize or eliminate these biases. Nevertheless, the proposed model is open to new discoveries that may occur regarding this matter. However, even in the case of a lege ferenda model, one can from it criticize de lege lata of the Brazilian Positive Law and demonstrate that many of the common biased practices in daily forensic activities could have already been confronted / A imparcialidade, sendo nota essencial à jurisdição, é dentre outras coisas garantia das partes e da própria manutenção da Democracia. No que concerne especificamente à imparcialidade subjetiva, para que seja minimamente resguardada, é preciso que os sistemas de direito processual atualmente vigentes no Brasil caminhem em sentido oposto ao rumo que estão tomando, já que têm alimentado fatores de enviesamento cognitivo dos julgadores e, portanto, uma quebra inconsciente e sistêmica de suas imparcialidades. Nesse sentido, o presente trabalho propõe uma reforma legislativa, oferecendo um modelo precaucional de lege ferenda inspirado em estratégias algorítmicas fundadas nas mais recentes descobertas de uma nova disciplina cada vez mais pujante em países anglo-saxões, Israel e Europa Ocidental chamada Behavioral Law & Economics (resultante de uma fusão entre Direito, Psicologia Cognitiva e Economia Comportamental). Daí por que se trata de um trabalho de engenharia jurídica. Ora, partindo da premissa de que todo e qualquer tomador de decisão é provido de uma racionalidade limitada (que não se confunde propriamente com irracionalidade ), essas técnicas buscam desfazer ou isolar os efeitos dos chamados vieses cognitivos , que nada mais são do que atalhos simplificadores previsíveis e, portanto, evitáveis que a mente humana desenvolve para tomar decisões a partir de informações complexas sob situação de incerteza. Assim sendo, estudar-se-ão as principais ilusões cognitivas que acometem os julgadores (viés de representatividade, viés de ancoragem e ajustamento, viés de confirmação e viés de grupo) e as normas processuais mais adequadas à neutralização, mitigação ou à eliminação desses vieses. Não obstante, o modelo proposto é aberto às novas descobertas que vierem porventura a ocorrer nessa matéria. Todavia, ainda que se trate de um modelo de lege ferenda, a partir dele se podem tecer críticas de lege lata ao direito positivo brasileiro e demonstrar que muitas das práticas enviesantes corriqueiras no dia a dia forense já poderiam estar sendo combatidas

Submitted by carolina da rocha frigerio kern (carolfrigerio@hotmail.com) on 2015-12-03T18:56:38Z No. of bitstreams: 1 Dissertação - Carolina Kern.pdf: 6779685 bytes, checksum: 144cc5dc364ecdc5e259325de6c72322 (MD5) / Approved for entry into archive by Janete de Oliveira Feitosa (janete.feitosa@fgv.br) on 2015-12-11T12:14:49Z (GMT) No. of bitstreams: 1 Dissertação - Carolina Kern.pdf: 6779685 bytes, checksum: 144cc5dc364ecdc5e259325de6c72322 (MD5) / Approved for entry into archive by Marcia Bacha (marcia.bacha@fgv.br) on 2015-12-21T13:18:37Z (GMT) No. of bitstreams: 1 Dissertação - Carolina Kern.pdf: 6779685 bytes, checksum: 144cc5dc364ecdc5e259325de6c72322 (MD5) / Made available in DSpace on 2015-12-21T13:18:55Z (GMT). No. of bitstreams: 1 Dissertação - Carolina Kern.pdf: 6779685 bytes, checksum: 144cc5dc364ecdc5e259325de6c72322 (MD5) Previous issue date: 2015-11-17 / Mergers and acquisitions activities, also known in the market as M&A, have been an important strategy adopted by CEOs to ensure domestic and international competitiveness, motivated by many reasons: need for growth, market share increase, entry barriers increase/growth, knowledge acquisition (human capital, tecnology and process), synergies, among others. Even though there are studies about M&A seeking for a better understanding of the problems related to strategy and decision making process alignment, critical success factors, due diligence best practices, valuations and integrations needs during the implementation of a merger or acquisition, only a few have focused on the cognitive biases of a M&A decision making process. In this way, the main purpose of this research is to present a consolidation of the main hidden traps in M&A decision making process. In a complementary manner, this study also sought the following secondary goals: understand the process of mergers and acquisitions, identify the main steps and decision points in the M&A process, analyse the traps regarding a decision making process. Therefore, it was conducted a qualitative research contemplating interviews with 15 profissionals that have had relevant participation on M&A projects of brazilian companies from different industries that have been merged, have acquired or have been acquired by another company, between 2009 and 2015. The informations obtained in the interviews were consolidated and analysed by the discourse analysis methodology. As a result, this research showed that M&A decisions are extremely complex and involve great uncertainty, which implies a bigger risk of decision traps occurrence. Among these hidden traps that have greater influence in M&A decisions, according to this study, contextualization was the one that presented the most dominance, followed by evidence of confirmation and anchoring. / A atividade de fusões e aquisições, também conhecida no mercado como M&A (Mergers and Acquisitions), tem sido uma relevante estratégia adotada pelos CEOs para garantir a competitividade em mercados doméstico e internacional, sendo justificada por diversos fatores, dentre eles: necessidade de crescimento, aumento do market share, criação e/ou aumento de barreiras de entrada, aquisição de conhecimento (capital humano, tecnologia e processos) e busca por sinergias. Ainda que existam estudos sobre M&A visando uma melhor compreensão dos problemas relacionados ao alinhamento entre a estratégia e a tomada de decisão, dos fatores críticos de sucesso, melhores práticas para condução de due diligence (processo de investigação e auditoria), valorações econômicas e integrações na implementação da fusão ou aquisição, poucos se debruçaram em analisar as armadilhas do processo decisório de M&A, no que diz respeito aos vieses psicológicos existentes ao longo da tomada de decisão. Desta forma, o objetivo central da presente pesquisa é apresentar a consolidação da análise das principais armadilhas que interferem no processo decisório de fusões e aquisições. De maneira complementar, também se almejou alcançar os seguintes objetivos intermediários: compreender o processo de fusões e aquisições; identificar as principais etapas e pontos de decisão no processo decisório de fusões e aquisições; analisar as armadilhas inerentes a uma tomada de decisão. Assim, foi realizada uma pesquisa qualitativa que, além de revisão de literatura, contou com a realização de entrevistas com 15 profissionais que tiveram atuação relevante em projetos de M&A de empresas brasileiras que adquiriram, foram adquiridas ou realizaram fusões entre 2009 e 2015, em diversos segmentos da indústria. As informações obtidas foram compiladas e analisadas através da metodologia de Análise de Discurso. Como resultado, esta pesquisa mostrou que decisões de M&A são extremamente complexas e apresentam alto grau de incerteza, o que implica em um maior risco da ocorrência de armadilhas psicológicas. Dentre as armadilhas que exercem maior influência nas decisões de fusões e aquisições, de acordo com este estudo, a contextualização foi a que apresentou maior dominância, seguida pela evidência de confirmação e ancoragem.

Submitted by Joel de Lima Pereira Castro Junior (joelpcastro@uol.com.br) on 2016-07-23T21:45:30Z No. of bitstreams: 1 VivianFrança.pdf: 2881557 bytes, checksum: 1ce976b103742f469288ae61c5b5fec4 (MD5) / Approved for entry into archive by Biblioteca de Administração e Ciências Contábeis (bac@ndc.uff.br) on 2016-08-03T18:45:49Z (GMT) No. of bitstreams: 1 VivianFrança.pdf: 2881557 bytes, checksum: 1ce976b103742f469288ae61c5b5fec4 (MD5) / Made available in DSpace on 2016-08-03T18:45:49Z (GMT). No. of bitstreams: 1 VivianFrança.pdf: 2881557 bytes, checksum: 1ce976b103742f469288ae61c5b5fec4 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Centro Universitário Hermínio da Silveira (IBMR) / O objetivo desta pesquisa é identificar os vieses cognitivos que motivaram os funcionários da Petrobras a tomarem a decisão de aderir ao Plano de Demissão Voluntária (PDV). Como objetivos específicos têm-se: a) compreender como os vieses cognitivos agiram no processo de decisão de adesão ao PDV; b) identificar como os vieses cognitivos agiram nos funcionários que não aderiram ao PDV nesta mesma época. Para isso, realizou-se uma pesquisa de natureza quantitativa, com a aplicação de dois questionários padronizados, direcionado para cada perfil de sujeitos da pesquisa. Estes totalizaram em 61 respondentes, sendo 31 Pedevistas (sujeitos que aderiram ao PDV) e 30 Não Pedevistas (sujeitos que não aderiram ao PDV). Para análise dos dados utilizou-se o site de gerenciamento de pesquisa www.enquetefacil.com e para as análises complementares de estatística o software SPSS (Statistical Package for the Social Sciences), como forma de garantir a fidedignidade das informações obtidas. Constatou-se que em muitos momentos Pedevistas e Não Pedevistas comportaram-se de maneira muito similar, minimizando qualquer possibilidade de diferenças estatísticas observadas. Em outros momentos, os Pedevistas revelaram-se como indivíduos menos analíticos, excessivamente confiantes e ingênuos. Enquanto os Não Pedevistas também demostraram-se ser potencialmente confiantes, porém analíticos e conservadores. Conclui-se que os Não Pedevistas conseguiram usufruir positivamente do potencial adverso das heurísticas de julgamento e seus vieses cognitivos, consequentemente obtiveram melhores resultados com a sua decisão. No entanto, os Pedevistas foram potencialmente prejudicados pelos efeitos negativos dos vieses cognitivos e até hoje sofrem os danos gerados pela decisão de tomaram. / The purpose of this research is to identify the cognitive biases that motivated employees of Petrobras to take the decision to join the Plano de Demissão Voluntária – PDV. The specific objectives are to: a) understand how cognitive biases acted in decision to join the PDV b) identify how cognitive biases acted in employees who do not adhere to this same time PDV. Then, we carried out a quantitative survey applicated by two standardized questionnaires, directed to each profile of research subjects. These totaled in 61 respondents, 31 Pedevistas (subjects who adhered to PDV) and 30 Non Pedevistas (subjects who did not adhere to PDV). Data analysis used the site management and www.enquetefacil.com search for complementary analyzes of the statistical software SPSS (Statistical Package for the Social Sciences), in order to guarantee the reliability of information obtained. It was found that in many instances that not Pedevistas and Pedevistas behaved in a very similar manner, minimizing any possible statistical differences observed. At other times, Pedevistas proved as individuals less analytical, overly trusting and naive. While not Pedevistas demonstrated to be potentially confident, analytical and conservative. We conclude that Pedevistas could take advantage of the positive potential adverse judgment heuristics and their cognitive biases, thus reached better results with his decision. However, Pedevistas were potentially affected by the negative effects of cognitive biases and still suffer the damage caused by the decision taken.

Certains problèmes ne peuvent être résolus ni par les ordinateurs seuls ni par les humains seuls. La visualisation d'information est une solution commune quand il est nécessaire de raisonner sur de grandes quantités de données. Plus une visualisation est efficace, plus il est possible de résoudre des problèmes complexes. Dans la recherche en visualisation d'information, une visualisation est généralement considérée comme efficace quand elle permet de comprendre les données. Les méthodes d'évaluation cherchent à déterminer si les utilisateurs comprennent les données affichées et sont capables d'effectuer des tâches analytiques comme, par exemple, identifier si deux variables sont corrélées. Cette thèse suggère d'aller au-delà de ce ``paradigme de l'analyse visuelle'' et élargir le champ de recherche à un autre type de tâche: la prise de décision. Les tâches de décision sont essentielles à tous, du directeur d'entreprise qui doit prendre des décisions importantes à l'individu ordinaire qui choisit un plan de carrière ou désire simplement acheter un appareil photo. Néanmoins, les décisions ne se résument pas à la simple compréhension de l'information et sont difficiles à étudier. Elles peuvent impliquer des préférences subjectives, n'ont pas toujours de vérité de terrain, et dépendent souvent de connaissances externes aux données visualisées. Pourtant, les tâches de décision ne font pas partie des taxonomies de tâches en visualisation et n'ont pas été bien définies. De plus, la recherche manque de métriques, de méthodes et de travaux empiriques pour valider l'efficacité des visualisations pour la prise de décision. Cette thèse offre une définition opérationnelle pour une classe particulière de tâches de décision, et présente une analyse systématique qui identifie les visualisations multidimensionnelles compatibles avec ces tâches. Elle présente en outre la première comparaison empirique de techniques de visualisation multidimensionnelle basée sur leur capacité à aider la décision, et esquisse une méthodologie et des métriques pour évaluer la qualité des décisions. Elle explore ensuite le rôle des instructions dans les tâches de décision et des tâches analytiques équivalentes, et identifie des différences de performance entre les deux tâches. De même que les sciences de la vision informent la visualisation d'information sur les limites de la vision humaine, aller au-delà du paradigme de l'analyse visuelle implique de prendre en compte les limites du raisonnement humain. Cette thèse passe en revue la théorie de la décision afin de mieux comprendre comment les humains prennent des décisions, et formule une nouvelle taxonomie de biais cognitifs basée sur la tâche utilisateur. En outre, elle démontre empiriquement que des biais peuvent être présents même quand l'information est bien visualisée, et qu'une décision peut être ``correcte'' mais néanmoins irrationnelle, dans le sens où elle est influencée par des informations non pertinentes. Cette thèse examine finalement comment mitiger les biais. Les méthodes pour améliorer le raisonnement humain reposent souvent sur un entraînement intensif à des principes et à des procédures abstraites, qui se révèlent souvent peu efficaces. Les visualisations offrent une opportunité dans la mesure où ses concepteurs peuvent remodeler l'environnement pour changer la façon dont les utilisateurs assimilent les données. Cette thèse passe en revue la théorie de la décision pour identifier de possibles solutions de conception. De plus, elle démontre empiriquement que supplémenter une visualisation par des interactions qui facilitent des stratégies de décision alternatives peut mener à des décisions plus rationnelles. Via des études empiriques, cette thèse suggère que le paradigme de l'analyse visuelle n'est pas en mesure de relever tous les défis de la prise de décision aidée de la visualisation, mais qu'aller au-delà peut contribuer à faire de la visualisation un puissant outil de prise de décision. / There are problems neither humans nor computers can solve alone. Computer-supported visualizations are a well-known solution when humans need to reason based on a large amount of data. The more effective a visualization, the more complex the problems that can be solved. In information visualization research, to be considered effective, a visualization typically needs to support data comprehension. Evaluation methods focus on whether users indeed understand the displayed data, can gain insights and are able to perform a set of analytic tasks, e.g., to identify if two variables are correlated. This dissertation suggests moving beyond this "visual analysis paradigm" by extending research focus to another type of task: decision making. Decision tasks are essential to everybody, from the manager of a company who needs to routinely make risky decisions to an ordinary person who wants to choose a career life path or simply find a camera to buy. Yet decisions do not merely involve information understanding and are difficult to study. Decision tasks can involve subjective preferences, do not always have a clear ground truth, and they often depend on external knowledge which may not be part of the displayed dataset. Nevertheless, decision tasks are neither part of visualization task taxonomies nor formally defined. Moreover, visualization research lacks metrics, methodologies and empirical works that validate the effectiveness of visualizations in supporting a decision. This dissertation provides an operational definition for a particular class of decision tasks and reports a systematic analysis to investigate the extent to which existing multidimensional visualizations are compatible with such tasks. It further reports on the first empirical comparison of multidimensional visualizations for their ability to support decisions and outlines a methodology and metrics to assess decision accuracy. It further explores the role of instructions in both decision tasks and equivalent analytic tasks, and identifies differences in accuracy between those tasks. Similarly to vision science that informs visualization researchers and practitioners on the limitations of human vision, moving beyond the visual analysis paradigm would mean acknowledging the limitations of human reasoning. This dissertation reviews decision theory to understand how humans should, could and do make decisions and formulates a new taxonomy of cognitive biases based on the user task where such biases occur. It further empirically shows that cognitive biases can be present even when information is well-visualized, and that a decision can be ``correct'' yet irrational, in the sense that people's decisions are influenced by irrelevant information. This dissertation finally examines how biases can be alleviated. Current methods for improving human reasoning often involve extensive training on abstract principles and procedures that often appear ineffective. Yet visualizations have an ace up their sleeve: visualization designers can re-design the environment to alter the way people process the data. This dissertation revisits decision theory to identify possible design solutions. It further empirically demonstrates that enriching a visualization with interactions that facilitate alternative decision strategies can yield more rational decisions. Through empirical studies, this dissertation suggests that the visual analysis paradigm cannot fully address the challenges of visualization-supported decision making, but that moving beyond can contribute to making visualization a powerful decision support tool.