The purpose of this study is to explore how experienced student writers in Swedish schools handle two different writing tasks, a lab report in physics and a text to be written within Swedish as a school subject. Applying a dialogical perspective on writing, the study is an attempt to explore what role subject contexts play for the students’ writing processes and to what extent the strategies used by the students are more individual. The writing tasks were solved outside of class, a frequent, but relatively unexplored way of organizing writing tasks in upper secondary school in Sweden.The results of the study indicate that different subject contexts enforce the emergence of different writing processes. The lab report was written in a certain order, from easy to difficult parts. Each part of the text was written on its own. Editing affecting the macrostructure of the text did not occur. In contrast, when writing the text within Swedish as a school subject, the paragraphs were developed at several different times during the writing process and questions concerning the global structure of the text seem constantly to have presented themselves. Extensive deletions were performed, and new angles to the subject introduced, affecting the macrostructure of the text.Writing processes are also individual. In a close-up study, three students – here called Kerstin, Paula and Sara – video filmed their work with the two texts. The texts were logged by the students, writing on Google Drive. In this material the individual strategies come out in basically two ways: in the resources chosen by the students as well as in their editing of their texts. Kerstin may be said to have used “herself” or, rather, a general writing ability. For Paula, her father functioned as an important resource. Sara was the one of the three who used digital media most frequently. In the students’ editing patterns, above all, Kerstin and Sara differed significantly. Kerstin did her editing during the formulation stage, regardless of writing task, while Sara mainly did her editing after the formulation stage.

This thesis provides a detailed analysis of the so-called `house money' or windfall endowment effect and its main determinants. Chapter 1 provides a detailed survey on the literature related to the house money effect. This effect according to Thaler and Johnson (1990) - refers to the situation where prior gains mitigate the influence of loss aversion and facilitate risk-seeking. The concept borrows its name from the expression employed in the gambling parlance of "playing with the house money", which is used when people gamble while ahead. As the literature has used a variety of concepts and ideas to describe the house money effect, this chapter presents and discusses them within the environment and the related literature that they have emerged. This is done in order to highlight the predominant answers to the main research questions raised in the various strands of the literature, namely: (i) whether people treat money differently depending on its origin; and (ii) the implications of the house money effect for the experimental methodology in economics. The literature is organised and presented according to the context in which the above two research questions have been examined. By presenting results in each particular context, we pin down the contextual differences that might be responsible for the presence (or absence) of the house money effect, and lay the initial ground work to answer a third research question: What drives the house money effect? In this regard, after we demonstrate the context-dependency of the house money effect we present the two main interpretations that it has received, namely that the house money effect is a result of different mental accounting over windfall gains (`windfall effect') or a result of fairness or deservingness concerns ('Lockean desert effect'). Chapter 2 re-examines the house money effect and explores its main driving forces. For that, we employ a novel experimental design utilising a within-subject approach, coupled with the use of three different contexts of economic decisions (a trust game, a set of lotteries and a public good game). Both the within-subject experimental design and the three contexts of economic decisions allow us to better test the two main interpretations of the house money effect. Our experimental data confirm the presence of the house money effect both in the decision to trust (but not in the decision of trustworthiness) in the trust game and in the decision to contribute in the public account of the public good game. However, our findings do not support the hypothesis that changes in risk behaviour of participants are due to different sources of money, suggesting that risk attitudes are robust and independent of the origin of money along the experiment. Therefore, our findings seem to favour interpretations of the house money effect as a result of 'just desert' or fairness preferences rather than the result of different mental accounting over windfall gains. Chapter 3 combines two branches of experimental literature, namely the house money effect and the literature on individual differences in social preferences. Both the house money effect and individual differences have been used extensively to explain cooperation in social dilemmas (and its decline over time). Here, we test the implications of house money on reciprocal behaviour, that is, whether participants in economic experiments are less likely to reciprocate when earned money rather than windfall money is at stake. Using the innovative experimental design of Fischbacher et al. (2001) with strategy method, we classify participants according to their behaviour in a linear public good game, and by adding the within-subject element in our experimental design we test the robustness of this classification across the different origin of endowments. Our results indicate that the types' classification is robust across the origin of money. Contrary to Harrison (2007), we find that participants' decision to free ride or not (contribute or not) is independent of the origin of money, but given that the decision to contribute has been made, contribution levels may vary -actually be lower- when money is earned rather than windfall endowed. We also elicit beliefs about others' contributions and test how these beliefs affected by the "house money" and in turn how they affect the decision to contribute. This discussion relates to what the literature has characterised so far as "anticipatory reciprocity".

abstract: Bridging semantic gap is one of the fundamental problems in multimedia computing and pattern recognition. The challenge of associating low-level signal with their high-level semantic interpretation is mainly due to the fact that semantics are often conveyed implicitly in a context, relying on interactions among multiple levels of concepts or low-level data entities. Also, additional domain knowledge may often be indispensable for uncovering the underlying semantics, but in most cases such domain knowledge is not readily available from the acquired media streams. Thus, making use of various types of contextual information and leveraging corresponding domain knowledge are vital for effectively associating high-level semantics with low-level signals with higher accuracies in multimedia computing problems. In this work, novel computational methods are explored and developed for incorporating contextual information/domain knowledge in different forms for multimedia computing and pattern recognition problems. Specifically, a novel Bayesian approach with statistical-sampling-based inference is proposed for incorporating a special type of domain knowledge, spatial prior for the underlying shapes; cross-modality correlations via Kernel Canonical Correlation Analysis is explored and the learnt space is then used for associating multimedia contents in different forms; model contextual information as a graph is leveraged for regulating interactions among high-level semantic concepts (e.g., category labels), low-level input signal (e.g., spatial/temporal structure). Four real-world applications, including visual-to-tactile face conversion, photo tag recommendation, wild web video classification and unconstrained consumer video summarization, are selected to demonstrate the effectiveness of the approaches. These applications range from classic research challenges to emerging tasks in multimedia computing. Results from experiments on large-scale real-world data with comparisons to other state-of-the-art methods and subjective evaluations with end users confirmed that the developed approaches exhibit salient advantages, suggesting that they are promising for leveraging contextual information/domain knowledge for a wide range of multimedia computing and pattern recognition problems. / Dissertation/Thesis / Ph.D. Computer Science 2011

This essay reflects a final thesis work of exploring future opportunities of temporary storing in future car interiors. The work is based from user studies and supported by designers of the automotive industry. The exploratorypart focuses on contextual video interviews studying the use of the interior storage space. Categories are created from the studies to investigate several possibilities parallel throughout the work. A category of exible space is chosen to being developed into a nal design proposal. The result is a concept called LVL - A exible surface that o ers di erent use of the same space.

The primary visual cortex (V1) has long been considered the main low level visual analysis area of the brain. The classical view is of a feedfoward system functioning as an edge detector, in which each cell has a receptive field (RF) and a preferred orientation. Whilst intuitive, this view is not the whole story. Although stimuli outside a neuron’s RF do not result in an increased response by themselves, they do modulate a neuron’s response to what’s inside its RF. We will refer to such extra-RF effects as contextual modulation. Contextual modulation is thought to underlie several perceptual phenomena, such as various orientation illusions and saliency of specific features (such as a contour or differing element). This gives a view of V1 as more than a collection of edge detectors, with neurons collectively extracting information beyond their RFs. However, many of the accounts linking psychophysics and physiology explain only a small subset of the illusions and saliency effects: we would like to find a common principle. So first, we assume the contextual modulations experienced by V1 neurons is determined by the elastica model, which describes the shape of the smoothest curve between two points. This single assumption gives rise to a wide range of known contextual modulation and psychophysical effects. Next, we consider the more general problem of encoding and decoding multi-variate stimuli (such as center surround gratings) in neurons, and how well the stimuli can be decoded under substantial noise levels with a maximum likelihood decoder. Although the maximum likelihood decoder is widely considered optimal and unbiased in the limit of no noise, under higher noise levels it is poorly understood. We show how higher noise levels lead to highly complex decoding distributions even for simple encoding models, which provides several psychophysical predictions. We next incorporate more updated experimental knowledge of contextual modulations. Perhaps the most common form of contextual modulations is center surround modulation. Here, the response to a center grating in the RF is modulated by the presence of a surrounding grating (the surround). Classically this modulation is considered strongest when the surround is aligned with the preferred orientation, but several studies have shown how many neurons instead experience strongest modulation whenever center and surround are aligned. We show how the latter type of modulation gives rise to stronger saliency effects and unbiased encoding of the center. Finally, we take an experimental perspective. Recently, both the presence and the underlying mechanisms of contextual modulations has been increasingly studied in mice using calcium imaging. However, cell signals extracted with calcium imaging are often highly contaminated by other sources. As contextual effects beyond center surround modulation can be subtle, a method is needed to remove the contamination. We present an analysis toolbox to de-contaminate calcium signals with blind source separation. This thesis thus expands our understanding of contextual modulation, predicts several new experimental results, and presents a toolbox to extract signals from calcium imaging data which should allow for more in depth studies of contextual modulation.

This research is concerned with how in/security is understood and the implications of contested meanings of in/security. The basic premise of this thesis is that in/security in itself has no meaning and thus cannot exist in isolation. Instead, in/security is always defined in relation to something or someone. How we understand in/security derives from the contexts we navigate and the identities we construct. An inquiry into in/security therefore demands incorporating a multiplicity of narratives and discussing these in relation to each other. While scholars have called for a greater emphasis on exploring in/security in marginal sites, I argue that accounts from the margins must not be at the exclusion of other more dominant narratives. Such analysis – placing the elite/margin, included/excluded, powerful/weak – in the same framework in order to produce a relational account of in/security is largely missing. This thesis sets out to provide a rich and detailed understanding of the everyday complexities of in/security. I propose a framework for capturing relational and contextual dimensions of in/security, and the implication of contested meanings of in/security understandings. Through an in-depth case study in the context of the transitions towards a post-conflict period in Colombia, following five decades of armed conflict, I inquired into in/security understandings at the margins in relation to the centre. The margins were represented by conflict-affected communities whereas the centre was represented by the Colombian government and key security sector institutions. The research found several relational dimensions of in/security understandings between the state- and the marginalized community-levels. Moreover, contextual and identity factors had a significant impact on how in/security was spoken about and what was spoken of. Through the framework, it was possible to see in continuum the way deeply ingrained understandings of in/security reproduce violence as the government seeks to transition the country into a post-conflict period following five decades of armed conflict. The research, through a detailed empirical case study, supports the view that in/security is relational and derivative of context and with ties to identity. It contributes to further our understandings of in/security at three distinct levels. At the theoretical level, the research builds upon existing literature in the field of security studies to advance an enhanced understanding of the relational and contextual dimensions of in/security, the contested meanings of in/security and the implications thereof. Methodologically, it proposes an alternative framework to capture the relational dimensions through shifting the problem formulation from a traditional focus on who is to be secured from what threats to how in/security is understood by different people/communities in different contexts. Empirically, it contributes to an off-centred understanding of in/security dynamics in the official transitions into the post-conflict period in Colombia. Through its empirical evidence it has the potential to offer an important contribution to the analysis of post-conflict transitions more generally.

A extinção é uma forma de aprendizado inibitório que se origina na omissão do reforço ou estímulo incondicionado, inibindo a evocação de uma resposta ou comportamento aprendido anteriormente. Muitas formas de aprendizado são moduladas por receptores β- noradrenérgicos, D1-dopaminérgicos e H2-histaminérgicos no córtex pré-frontal ventromedial (vmPFC), no complexo basolateral da amígdala (BLA) e no hipocampo dorsal (DH). Assim, o objetivo do presente trabalho foi investigar a modulação da extinção de memória aversiva nestas três regiões cerebrais. Para isso, utilizamos ratos machos Wistar, que foram submetidos ao paradigma de esquiva inibitória (EI) ou condicionamento contextual ao medo (CCM). As diferentes drogas utilizadas foram infundidas através das cânulas guias implantadas estereotaxicamente no DH, BLA ou vmPFC imediatamente após a sessão de extinção e seus efeitos sobre a extinção foram avaliados em uma sessão de teste realizada 24 h depois. A DSerina (50 μg/lado), modulador positivo do receptor NMDA, e o SKF9188 (12.5 μg/lado), inibidor da enzima histamina metil-transferase, melhoraram a consolidação da memória de extinção nas tarefas de EI e CCM. Entretanto, o AP5 (5 μg/lado), antagonista do receptor glutamatérgico NMDA, e a ranitidina (17.5 μg/lado), antagonista do receptor histaminérgico H2, prejudicaram a extinção em ambos os paradigmas, indicando que os receptores glutamatérgicos do tipo NMDA estão envolvidos na consolidação dos dois paradigmas utilizados, e que os receptores histaminérgicos H2 modulam a extinção nas três estruturas estudadas. A noradrenalina (1 μg/lado), o antagonista β-adrenoreceptor, timolol (1 μg/lado), o agonista dos receptores D1, SKF38393 (12.5 μg/lado) e o antagonista dos receptores D1, SCH23390 (1.5 μg/lado) também afetam a extinção nas duas tarefas, porém, seus efeitos são variados dependendo da tarefa e do local da infusão, sugerindo que a modulação da extinção pelos receptores β- e D1 é mais complexa. Nossos resultados mostram que as três estruturas são ativadas durante o processo de extinção da memória e que os sistemas neuromodulatórios atuam de formas distintas nessas tarefas. / Extinction consists of the learned inhibition of retrieval of previously acquired memory. Many forms of learning are modulated by β-noradrenergic, D1-dopaminergic and H2-histaminergic receptors on ventromedial prefrontal cortex (vmPFC), basolateral amygdala (BLA) and dorsal hippocampus. Therefore, the aim of this work was investigated the modulation of aversive memory extinction in these brain structures. Male Wistar rats were submitted to inhibitory avoidance paradigm (EI) or contextual fear conditioning (CCM). The drugs were infused through cannulae implanted into the DH, BLA or vmPFC immediately after the extinction session and their effects were evaluated 24 h later. D-serine (50 μg/side), a NMDA receptor stimulant, and SKF9188 (12.5 μg/side), a histamine methyl-transferase inhibitor, enhanced the consolidation of the extinction memory in EI and CCM tasks. However, AP5 (5 μg/side), a NMDA-antagonist, and ranitidine (17.5 μg/side), a H2- histaminergic antagonist, impaired the extinction of both tasks, indicated that NMDA receptors are involved in the consolidation of extinction of both tasks, and histamine H2 receptors modulate that process in all areas studied. Noradrenaline (1 μg/side), timolol 1 μg/side), a β-adrenergic antagonist, SKF38393 (12.5 μg/side) and SCH23390 (1.5 μg/side), D1 agonist and antagonist receptor, respectively, also affected the extinction, but their effects varied with the task and with the site of infusion, suggesting that extinction modulation by β- and D1 is more complex. In conclusion, the three structures investigated are activated in the aversive memory extinction and the neuromodulatory systems act of different forms in these structures.

Made available in DSpace on 2015-07-22T20:50:14Z (GMT). No. of bitstreams: 0 Previous issue date: 2010-04-28 / Associação Fundo de Incentivo à Psicofarmacologia (AFIP) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / A sensibilização comportamental refere-se ao aumento progressivo do efeito estimulante induzido após repetidas administrações de drogas de abuso como cocaína e anfetaminas. Estudos prévios sugerem que o ambiente pareado aos efeitos destas drogas parece ter um importante envolvimento no fenômeno da sensibilização comportamental. Além disso, o tratamento com uma droga de abuso pode interferir com a resposta comportamental eliciada por outra, quando essas possuirem algum mecanismo de ação comum. O presente estudo teve como objetivo investigar o envolvimento da aprendizagem contextual no fenômeno da sensibilização comportamental induzida pelo modafinil e metanfetamina e se haveria uma sensibilização cruzada entre as duas drogas. Os animais foram treinados e testados na tarefa do condicionamento de medo ao contexto (CMC). Após 15 dias foi realizado o teste da novidade, sem nenhuma manipulação farmacológica, às caixas de atividade locomotora. Para avaliar o desenvolvimento da sensibilização comportamental, após 24 horas do teste da novidade grupos diferentes de animais receberam injeções diárias de modafinil (50mg/kg) ou veículo (Experimento 2) e metanfetamina (1mg/kg) ou salina (Experimento 3) via ip por 10 dias e a atividade locomotora foi registrada nos dias 1, 5 e 10. Para avaliar a expressão da sensibilização comportamental, todos os animais foram desafiados com veículo e modafinil (50mg/kg - Experimento 2) e salina e metanfetamina (1mg/kg - Experimento 3) nas caixas de atividade e no campo aberto. No teste de sensibilização cruzada animais pré-tratados com veículo e modafinil receberam uma dose aguda de metanfetamina (Experimento 2) e animais pré-tratados com salina e metanfetamina receberam uma dose aguda de modafinil (Experimento 3). Em ambos os experimentos foi verificado um aumento progressivo na atividade locomotora e uma evidente diferença individual nos níveis de sensibilização comportamental entre os animais tratados com as drogas. Nos experimentos 2 e 3, todos os animais apresentaram resposta similar de tempo de congelamento no teste CMC. A expressão da sensibilização ao modafinil foi observada no ambiente previamente pareado com as administrações e foi bloqueada no ambiente não pareado. No caso da metanfetamina a expressão ocorreu em ambos ambientes. Também foi observado sensibilização cruzada simétrica entre modafinil e metanfetamina. Os resultados do presente estudo apontam para um envolvimento da aprendizagem contextual na sensibilização comportamental, porém parece não ser generalizado para todas as drogas psicoestimulantes. Além disso, apontam que existe uma grande variabilidade individual ao desenvolvimento da sensibilização comportamental ao modafinil e à metanfetamina. Ainda pode-se sugerir que exista um mecanismo similar de ação entre o modafinil e a metanfetamina. / The behavioral sensitization refers to the progressive increase of the stimulatory effect induced by repeated administration of drugs of abuse such as cocaine and amphetamine. Previous studies suggest that the environment paired with the drug stimulant effect of those drugs has an important role in the behavioral sensitization phenomena. Besides, the chronic treatment with one drug of abuse can induce a different patter of response to the administration of other drug indicating that both drug share some similar mechanism of action. The present study aimed to investigate the involvement of contextual learning in the modafinil and methamphetamine behavioral sensitization phenomena and if there is cross-sensitization between the two drugs. Fifteen days after the contextual fear conditioning task, mice received repeated administration of vehicle or modafinil (50mg/kg - Experiment 2) and saline or methamphetamine (1mg/kg - Experiment 3) for 10 days; they were tested in activity cages on days 1, 5 and 10. To evaluate the expression of behavioral sensitization the mice were challenged with vehicle or modafinil (50mg/kg - Experiment 2) and saline or methamphetamine (1 mg/kg - Experiment 3) and then they were tested in the activity cages and in the open field arena. For cross-sensitization test, mice from Experiment 2 were challenged with saline and methamphetamine (1mg/kg) and those mice from Experiment 3 were challenged with vehicle and modafinil (50mg/kg). In both experiments we did not find any correlation between the levels of freezing in the contextual fear conditioning task and different levels of sensitization. Modafinil-sensitized subgroup of mice expressed clear behavioral sensitization in the activity cage, but not in the open field, suggesting a context-dependent expression of modafinil sensitization. We also observed a symmetric cross-sensitization between modafinil and methamphetamine. Our findings indicate that there are a important individual variability to the development of behavioral sensitization to methamphetamine and to modafinil. Besides, we suggest that modafinil and methamphetamine seem to share similar mechanisms of action. / FAPESP: 08/56049-0 / TEDE / BV UNIFESP: Teses e dissertações

Submitted by Maria Auxiliadora da Silva Lopes (silopes@ufba.br) on 2014-06-06T16:29:52Z No. of bitstreams: 1 Ivânia Paula de F. Souza _ Dissertação.pdf: 2192098 bytes, checksum: 6136e26293b5d91d93bdf551b87fcf87 (MD5) / Approved for entry into archive by Maria Auxiliadora da Silva Lopes (silopes@ufba.br) on 2014-06-06T16:30:34Z (GMT) No. of bitstreams: 1 Ivânia Paula de F. Souza _ Dissertação.pdf: 2192098 bytes, checksum: 6136e26293b5d91d93bdf551b87fcf87 (MD5) / Made available in DSpace on 2014-06-06T16:30:34Z (GMT). No. of bitstreams: 1 Ivânia Paula de F. Souza _ Dissertação.pdf: 2192098 bytes, checksum: 6136e26293b5d91d93bdf551b87fcf87 (MD5) / A Educação no Semiárido vem alcançando relevante destaque desde o final dos anos 1990 quando se iniciou a discussão sobre a Educação Contextualizada. Os municípios de Curaçá e Uauá, ambos na Bahia, pioneiros na sua implementação elaboraram suas Propostas Político-pedagógicas pautadas por princípios como inclusão, justiça e democracia. As Propostas se efetivaram desafiando a cultura política local marcada, especialmente, pela descontinuidade de processos e ações, fruto, sobretudo, de ingerências políticas e centralização do poder por parte dos representantes políticos e gestores públicos. As iniciativas mobilizaram importantes intervenções no currículo das redes de ensino e tem sido a principal via de aproximação das escolas com as demandas das comunidades, tanto na discussão de suas necessidades imediatas, como na projeção de outras possibilidades de vida e produção do conhecimento. As iniciativas pioneiras destes municípios foram alimento para a criação da Rede de Educação do Semiárido Brasileiro que contribuiu para expandir a Proposta de Educação Contextualizada como referência de política educacional que poderia alcançar um novo projeto social. Estas constatações foram trazidas por esta pesquisa, que objetivou adentrar nos processos de gestão desta Proposta nos dois municípios pioneiros, para compreender como estes se processam, sobretudo, evidenciando os condicionantes político-pedagógicos que lhes são presentes. A pesquisa de cunho qualitativo se constituiu de um estudo de caso não-comparativo dos dois municípios. Foram utilizadas diferentes estratégias de escuta dos sujeitos pesquisados, entre eles, professores, conselheiros da educação e gestores pedagógicos – incluindo aqui, as Secretárias de Educação. O período destacado compreende os anos de 2005 a 2010. A análise dos dados permitiu identificar alguns desafios que se colocam limites no processo de gestão da Educação Contextualizada, entre estes, a construção da autonomia sobre os processo de gestão financeira e política por parte das Secretarias de Educação, bem como o fortalecimento dos coletivos sociais dos municípios na efetiva democratização da gestão. / ABSTRACT Education in the Semiarid has achieved significant prominence since the late 1990s when it began the discussion of Contextual Education. The municipalities of Curaçá and Uauá, both in Bahia, pioneers in its implementation elaborated their political-pedagogical proposal guided by principles such as inclusion, justice and democracy.The Proposals if had accomplished defying the local culture marked politics, especially, for the discontinuity of processes and action, fruit, over all, of mediations politics and centralization of the power on the part of the representatives public politicians and managers. The initiatives had mobilized important interventions in the resume of the education nets and have been the main way of approach of the schools with the demands of the communities, as much in the quarrel of its immediate necessities, as in the projection of other possibilities of life and production of the knowledge. The pioneering initiatives of these cities had been food for the creation of the Net of Education of Brazilian Semiarid that contributed to expand the Proposal of contextual Education as reference of educational politics that could reach a new social Project.These findings had been brought by this research, that objectified to enter in the processes of management of this Proposal in the two pioneering cities, to understand as these if they process, over all, evidencing the politician-pedagogical conditions that them are gifts. The research of qualitative matrix if constituted of a case study not-comparative degree of the two cities. Different strategies of listening of the searched citizens had been used, between them, professors, pedagogical council members of the education and managers - including here, the Secretaries of Education. The detached period understands the years of 2005 the 2010. The analysis of the data allowed to identify some challenges that if place limits in the process of management of the contextual Education, between these, the construction of the autonomy on the process of financial management and politics on the part of the Secretariats of Education, as well as the reinforcement of collective social in the cities in the effective the democratization of the management.

Submitted by Santos Davilene (davilenes@ufba.br) on 2016-05-25T14:13:14Z No. of bitstreams: 1 Falcao_Dissertacao_MMCC_01082014.pdf: 8200381 bytes, checksum: b9473677ba0d01645a9c8c4f103b1161 (MD5) / Made available in DSpace on 2016-05-25T14:13:14Z (GMT). No. of bitstreams: 1 Falcao_Dissertacao_MMCC_01082014.pdf: 8200381 bytes, checksum: b9473677ba0d01645a9c8c4f103b1161 (MD5) / As empresas gastam muito dinheiro em publicidade para aumentar as suas vendas, entretanto a razão entre o que é investido e o que efetivamente gera vendas é baixa. Aumentar a utilidade dos anúncios é um desafio constante em publicidade que visa incrementar o retorno dos investimentos dos anunciantes, reduzir os desperdícios e elevar suas receitas. Publicidade ubíqua é o nome dado ao emprego de técnicas de computação ubíqua para solucionar problemas na área de publicidade, e um dos aspectos mais importantes de computação ubíqua é sensibilidade ao contexto. Cupons de desconto são uma forma de propaganda bastante popular. Estudos indicam que elementos contextuais (e.g. distância entre o consumidor e a loja, valor do desconto) influenciam a utilidade de cupons físicos (medida pela taxa de resgate) e que há sinergia entre eles. Esta pesquisa objetiva avaliar a influência do uso de contexto na utilidade de cupons de desconto para restaurantes de fast food distribuídos através de smartphones. Para isto, foi realizada, de forma incremental, a modelagem do contexto, partindo de um levantamento dos elementos contextuais do domínio. Este levantamento foi revisado e em seguida submetido à opinião de consumidores reais, que avaliaram a relevância de cada elemento contextual, apontaram novos elementos e apresentaram relações relevantes entre eles. A identificação dos elementos contextuais, suas relevâncias e suas relações deram origem a uma representação de contexto que foi chamada de Modelo de Sinergia Contextual. A partir da modelagem, foram realizadas três avaliações experimentais: primeiro, um estudo preliminar de sete dias com cinco voluntários, que instalaram protótipos em seus smartphones para perceberem os cupons; depois, um experimento invivo de trinta dias com dez participantes, através do uso de protótipos; e, finalmente, um experimento in virtuo com setenta participantes, realizado por meio de uma aplicação web. Este experimento final permitiu concluir que o uso de contexto aumenta a taxa de resgate de cupons de desconto no domínio investigado.