318 research outputs found

    Understanding “influence”: An exploratory study of academics’ process of knowledge construction through iterative and interactive information seeking

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    The motivation for this study is to better understand the searching and sensemaking processes undertaken to solve exploratory tasks for which people lack pre-existing frames. To investigate people’s strategies for that type of task, we focused on “influence” tasks because, although they appear to be unfamiliar, they arise in much academic discourse, at least tacitly. This qualitative study reports the process undertaken by academics of different levels of seniority to complete exploratory search tasks that involved identifying influential members of their academic community and “rising stars, ” and to identify similar roles in an unfamiliar academic community. 11 think-aloud sessions followed by semi-structured interviews were conducted to investigate the role of specific and general domain expertise in the process of information seeking and knowledge construction. Academics defined and completed the task through an iterative and interactive process of seeking and sensemaking, during which they constructed an understanding of their communities and determined qualities of “being influential”. Elements of the Data/Frame Theory of Sensemaking (Klein et al., 2007) were used as sensitising theoretical constructs. The study shows that both external and internal knowledge resources are essential to define a starting point or frame, make and support decisions, and experience satisfaction. Ill-defined or non-existent initial frames may cause unsubstantial or arbitrary decisions, and feelings of uncertainty and lack of confidence

    A Spreadsheet Approach to Facilitate Visualization of Uncertainty in Information

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    EZEL:a Visual Tool for Performance Assessment of Peer-to-Peer File-Sharing Networks

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    EZEL:a Visual Tool for Performance Assessment of Peer-to-Peer File-Sharing Networks

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    A Bayesian Abduction Model For Sensemaking

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    This research develops a Bayesian Abduction Model for Sensemaking Support (BAMSS) for information fusion in sensemaking tasks. Two methods are investigated. The first is the classical Bayesian information fusion with belief updating (using Bayesian clustering algorithm) and abductive inference. The second method uses a Genetic Algorithm (BAMSS-GA) to search for the k-best most probable explanation (MPE) in the network. Using various data from recent Iraq and Afghanistan conflicts, experimental simulations were conducted to compare the methods using posterior probability values which can be used to give insightful information for prospective sensemaking. The inference results demonstrate the utility of BAMSS as a computational model for sensemaking. The major results obtained are: (1) The inference results from BAMSS-GA gave average posterior probabilities that were 103 better than those produced by BAMSS; (2) BAMSS-GA gave more consistent posterior probabilities as measured by variances; and (3) BAMSS was able to give an MPE while BAMSS-GA was able to identify the optimal values for kMPEs. In the experiments, out of 20 MPEs generated by BAMSS, BAMSS-GA was able to identify 7 plausible network solutions resulting in less amount of information needed for sensemaking and reducing the inference search space by 7/20 (35%). The results reveal that GA can be used successfully in Bayesian information fusion as a search technique to identify those significant posterior probabilities useful for sensemaking. BAMSS-GA was also more robust in overcoming the problem of bounded search that is a constraint to Bayesian clustering and inference state space in BAMSS

    Information Visualization

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    Orientador : Prof. Dr. Cassyano Januário CorrerDissertação (mestrado) - Universidade Federal do Paraná, Setor de Ciências da Saúde, Programa de Pós-Graduação em Ciências Farmacêuticas. Defesa: Curitiba, 10/02/2015Inclui referências : f. [84-99]Área de concentração: Insumos, medicamentos e correlatosResumo: Antecedentes: A farmacoterapia antiobesidade ainda é alvo de amplo debate científico e político; não por acaso, já que há pouca confiabilidade tanto no âmbito dos estudos primários, quanto secundários, seja pelo reduzido tamanho amostral, elevada heterogeneidade e/ou baixa qualidade metodológica. Uma avaliação completa entre literatura existente sobre estudos primários e secundários é capaz de levantar recomendações para futuras pesquisas e também de fornecer resultados confiáveis relativos à eficácia e segurança. Objetivos: Avaliar a eficácia, segurança e relação risco-benefício de anfepramona (dietilpropiona), femproporex e mazindol. Métodos: Para isso revisão sistemática de estudos primários, seguida de metanálises diretas, de múltiplos tratamentos (MTC) e análise multicritério de risco-benefício foram conduzidas. Medline (via Pubmed), SCOPUS, Scielo e Directory of Open Access Journals foram pesquisadas desde a data de inserção até março de 2016. Modelo de efeitos randômicos foi escolhido para realização da metanálise direta e heterogeneidade foi avaliada pelo método do I2, associado ao valor de p. Para as comparações de múltiplos tratamentos, modelo de efeitos randômicos bayesiano foi utilizado, sendo fixado o placebo como comparador. Análises multicritério de risco-benefício utilizaram modelo de simulações de Monte Carlo, sendo realizadas segundo modelo estocástico. Resultados: De 739 publicações identificadas, 25 foram incluídas nas metanálises. A avaliação global da Cochrane resultou em 19 estudos com alto risco de viés e seis com risco incerto. Devido à falta de informação em estudos primários, metanálise direta só foi possível para avaliação de anfepramona, mazindol, comparados ao placebo. Anfepramona apresentou redução de peso corporal maior do que placebo tanto para tratamento de curta-duração (< 180 dias) diferença entre médias (DM) -1.281 kg (IC 95%: -1.538; -1.024), I2: 0.0% (p = 0.379), quanto para tratamentos de longa-duração (? 180 dias) DM de -6.518 kg (IC 95%: -8.419; -4.617), I2: 0.0% (p = 0.719). Apenas estudos de longa-duração reportaram eficácia segundo redução de circunferência abdominal, redução de 5% e 10% do peso corporal, confirmando a eficácia de anfepramona superior ao placebo. Mazindol apresentou redução de peso corporal superior ao placebo DM -1.721 kg (IC 95%: -2.164; -1.278), I2: 0.9% (p = 0.388) em tratamento de curta-duração. Desfechos metabólicos foram pobremente reportados, inviabilizando as metanálises. Segundo análise qualitativa, reações adversas graves foram identificadas apenas nos relatos de caso, em detrimento dos ensaios clínicos. MTC corroboram com metanálises diretas referentes à superioridade de eficácia para anfepramona em tratamento de longa-duração e anfepramona e mazindol em tratamentos de curta-duração. Análises de risco-benefício variaram a depender da duração do tratamento e do conjunto de desfechos escolhidos. Conclusões: Tanto pelo predomínio de alto risco de viés e ausência de desfechos importantes para a avaliação da terapia antiobesidade, os medicamentos avaliados não apresentaram evidências suficientes para confirmar sua eficácia para o tratamento da obesidade. No entanto, não foram identificados dados de segurança robustos que corroborem com sua retirada do mercado. Ensaios clínicos randomizados futuros poderiam realizar mais análises do tipo fármaco contra fármaco, com reporte dos desfechos mudança de circunferência abdominal, mudança de peso corporal, participantes com 5% e 10% de redução de peso e biomarcadores metabólicos (pressão arterial, lipídios e glicídios), ao longo de 3, 6, 9 e 12 meses. Palavras-chave: Obesidade; Perda de peso; Resultado do Tratamento; Prática Clínica Baseada em Evidências.Abstract: Background: Anti-obesity pharmacotherapy remains the main subject of disagreement among specialists, not only in the scientific field but also in the regulatory market. This is probably due to small sample size, high level of heterogeneity and low methodological quality. A thorough assessment of the existing literature (primary and secondary studies) can generate recommendations for future research and also provide reliable findings related to efficacy and safety. Objectives: To evaluate efficacy, safety and risk-benefit ratio of anfepramone (diethylpropion), femproporex and mazindol. Methods: We systematically reviewed primary studies and followed our review with direct meta-analysis, mixed treatment comparison (MTC), and multi-criteria benefit-risk assessment. Medline (via Pubmed), SCOPUS, Scielo and Directory of Open Access Journals were searched until Mar 2016. Random effect models were chosen to perform direct meta-analysis and heterogeneity was explored through I2 associated to p-value. For MTC, a random effect model was used, specifically fixed placebo as baseline treatment. Multi-criteria assessments were run through the Markov Chain Monte Carlo (stochastic model) method. Results: It was identified 739 publications, being 25 included in meta-analysis. The global evaluation of Cochrane resulted in 19 studies with high level of bias and six with uncertain risk. Due to lack of information in primary studies, direct meta-analysis was conducted only to diethylpropion and mazindol, both compared to placebo. Diethylpropion showed higher loss of weight compared to placebo in the short-term (< 180 days) mean difference (MD) -1.281 kg (CI 95%: -1.538; -1.024), I2: 0.0% (p = 0.379) and long-term (? 180 days) MD -6.518 kg (CI 95%: -8.419; -4.617), I2: 0.0% (p = 0.719). Only studies with long-term follow-up reported efficacy in terms of abdominal circumference and reductions of 5% and 10% of body weight. Their results corroborated diethylpropion efficacy greater than placebo. Mazindol showed a loss of weight greater than placebo MD -1.721 kg (CI 95%: -2.164; -1.278), I2: 0.9% (p = 0.388)) in the short term; metabolic outcomes were poorly described, preventing meta-analysis. According to qualitative assessment, major adverse reactions were reported only in case reports, not being described in clinical trials, what in turns presented only moderate and minor adverse reactions. MTC corroborated the direct meta-analysis concerning the superiority of efficacy for diethylpropion in long-term and diethylpropion and mazindol in short-term. Risk-benefit assessment results varied according to treatment duration and outcomes chosen. Conclusions: Considering the high level of risk of bias and absence of important outcomes for anti-obesity therapy assessment, there is not enough evidence to support the effectiveness of the drugs evaluated do not have enough evidence to support their effectiveness on the treatment of obesity. However, the data do not justify their withdrawal from the market. Future randomized clinical trials should explore comparisons among active drugs (head-to-head), reporting changes in abdominal circumference, body weight change, loss of 5 and 10% of body weight and also in metabolic biomarkers (blood pressure, lipids and glucose) throughout 3, 6, 9 and 12 months. Keywords: Obesity; Weight loss; Treatment Outcome; Evidence-Based Practice

    WebFrame: In Pursuit of Computationally and Cognitively Efficient Web Mining

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    Sensemaking and Group Relationships in Collaborative Exploratory Search

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    This study investigates the information seeking and sensemaking processes undertaken by groups engaged in collaborative exploratory searches. A second research question was what, if any, role the familiarity of the group members with each other had on how sensemaking occurred. Semi-structured interviews were conducted with eight participants, and each participant was asked to describe two collaborative search experiences, one with friends or family who they knew well, and one with an assigned group for school or work. Participants' experiences matched up well with existing information seeking models and current sensemaking models, but highlighted the importance of extensive use of artifacts and in-person communication as behaviors that facilitate sensemaking in a collaborative searching environment
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