952 resultados para cognitive task analysis


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Because outsourcing of information systems (IS) is now widespread, it is generally assumed to be successful. It is also often assumed that outsourcing risks are easily managed. In this paper we adopt an “evidence based management” approach to first test these assumptions through a qualitative metaanalysis of academic studies into IS outsourcing outcomes. Our research reveals a shortage of reliable and valid evidence for outsourcing’s benefits, and for the level of risk involved. We then use data from a series of focus groups to explain the paradox of widespread adoption of a strategy with limited empirical support. These focus groups were interpreted through the lens of research on a
range of cognitive mechanisms and biases that are known to affect decision makers. We conclude that cognitive mechanisms that are likely to affect sourcing decisions include framing biases, cognitive dissonance, attribution error, and the “optimism”, “confirmation”, “disconfirmation” and “overconfidence” biases. Given the shortage of supporting evidence, and the potential for these biases to operate, we argue that researchers need to be more critical in their analysis of reports of the success and risks of IS outsourcing.

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This paper addresses the problem of performance modeling for large-scale heterogeneous distributed systems with emphases on multi-cluster computing systems. Since the overall performance of distributed systems is often depends on the effectiveness of its communication network, the study of the interconnection networks for these systems is very important. Performance modeling is required to avoid poorly chosen components and architectures as well as discovering a serious shortfall during system testing just prior to deployment time. However, the multiplicity of components and associated complexity make performance analysis of distributed computing systems a challenging task. To this end, we present an analytical performance model for the interconnection networks of heterogeneous multi-cluster systems. The analysis is based on a parametric family of fat-trees, the m-port n-tree, and a deterministic routing algorithm, which is proposed in this paper. The model is validated through comprehensive simulation, which demonstrated that the proposed model exhibits a good degree of accuracy for various system organizations and under different working conditions.

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Objective:
To assess from a health sector perspective the incremental cost-effectiveness of cognitive behavioural therapy (CBT) and selective serotonin reuptake inhibitors (SSRIs) for the treatment of major depressive disorder (MDD) in children and adolescents, compared to ‘current practice’.
Method:
The health benefit is measured as a reduction in disability-adjusted life years (DALYs), based on effect size calculations from meta-analysis of randomised controlled trials. An assessment on second stage filter criteria (‘equity’; ‘strength of evidence’, ‘feasibility’ and ‘acceptability to stakeholders’) is also undertaken to incorporate additional factors that impact on resource allocation decisions. Costs and benefits are tracked for the duration of a new episode of MDD arising in eligible children (age 6–17 years) in the Australian population in the year 2000. Simulation-modelling techniques are used to present a 95% uncertainty interval (UI) around the cost-effectiveness ratios.
Results:
Compared to current practice, CBT by public psychologists is the most costeffective intervention for MDD in children and adolescents at A$9000 per DALY saved (95% UI A$3900 to A$24 000). SSRIs and CBT by other providers are less cost-effective but likely to be less than A$50 000 per DALY saved (> 80% chance). CBT is more effective than SSRIs in children and adolescents, resulting in a greater total health benefit (DALYs saved) than could be achieved with SSRIs. Issues that require attention for the CBT intervention include equity concerns, ensuring an adequate workforce, funding arrangements and acceptability to various stakeholders.
Conclusions:
Cognitive behavioural therapy provided by a public psychologist is the most
effective and cost-effective option for the first-line treatment of MDD in children and adolescents. However, this option is not currently accessible by all patients and will require change in policy to allow more widespread uptake. It will also require ‘start-up’ costs and attention to ensuring an adequate workforce.

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When building a cost-effective high-performance parallel processing system, a performance model is a useful tool for exploring the design space and examining various parameters. However, performance analysis in such systems has proven to be a challenging task that requires the innovative performance analysis tools and methods to keep up with the rapid evolution and ever increasing complexity of such systems. To this end, we propose an analytical model for heterogeneous multi-cluster systems. The model takes into account stochastic quantities as well as network heterogeneity in bandwidth and latency in each cluster. Also, blocking and non-blocking network architecture model is proposed and are used in performance analysis of the system. The message latency is used as the primary performance metric. The model is validated by constructing a set of simulators to simulate different types of clusters, and by comparing the modeled results with the simulated ones.

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Low dietary intakes of the n-3 long-chain PUFA (LCPUFA) EPA and DHA are thought to be associated with increased risk for a variety of adverse  outcomes, including some psychiatric disorders. Evidence from  observational and intervention studies for a role of n-3 LCPUFA in depression is mixed, with some support for a benefit of EPA and/or DHA in major depressive illness. The present study was a double-blind randomised controlled trial that evaluated the effects of EPA+DHA supplementation (1.5 g/d) on mood and cognitive function in mild to moderately depressed  individuals. Of 218 participants who entered the trial, 190 completed the planned 12 weeks intervention. Compliance, confirmed by plasma fatty acid concentrations, was good, but there was no evidence of a difference between supplemented and placebo groups in the primary outcome - namely, the depression subscale of the Depression Anxiety and Stress Scales at 12 weeks. Mean depression score was 8.4 for the EPA+DHA group and 9.6 for the placebo group, with an adjusted difference of - 1.0 (95 % CI - 2.8, 0.8; P = 0.27). Other measures of mood, mental health and cognitive function, including Beck Depression Inventory score and attentional bias toward threat words, were similarly little affected by the intervention. In conclusion, substantially increasing EPA+DHA intake for 3 months was found not to have beneficial or harmful effects on mood in mild to moderate depression. Adding the present result to a meta-analysis of previous relevant randomised controlled trial results confirmed an overall negligible benefit of n-3 LCPUFA supplementation for depressed mood.

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Shamanism has remained an integral part of indigenous healing rituals since ancient times and is currently attracting interest as a complementary therapeutic technique in psychology. Recently, shamanic-like techniques have been used to facilitate changes in the phenomenology of nonshamans. However, such research has largely been delimited to a single shamanic-like technique (i.e., drumming), and the role of personality traits with regards to receptivity to this technique has been neglected. The purpose of the present study was to investigate experimentally the effect of different shamanic-like techniques and the cognitive-perceptual factor of the schizotypy construct on phenomenology. One hundred and four non-shamans were randomly assigned to one of three conditions: Drumming, Ganzfeld, or Sitting Quietly with Eyes Open. Participants' phenomenology was assessed using the Phenomenology of Consciousness Inventory, Phenomenology associated with shamanic-like techniques appeared to be statistically significantly different from phenomenology associated with sitting quietly with eyes open. Furthermore, high cognitive-perceptual participants reported significant alterations in phenomenology compared to their low cognitive-perceptual counterparts. Methodological shortcomings of the present study are discussed and suggestions for future research are advanced.

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Aims. To explore and explain nurses' use of readily available clinical information when deciding whether a patient is at risk of a critical event.

Background. Half of inpatients who suffer a cardiac arrest have documented but unacted upon clinical signs of deterioration in the 24 hours prior to the event. Nurses appear to be both misinterpreting and mismanaging the nursing-knowledge 'basics' such as heart rate, respiratory rate and oxygenation. Whilst many medical interventions originate from nurses, up to 26% of nurses' responses to abnormal signs result in delays of between one and three hours.

Methods. A double system judgement analysis using Brunswik's lens model of cognition was undertaken with 245 Dutch, UK, Canadian and Australian acute care nurses. Nurses were asked to judge the likelihood of a critical event, 'at-risk' status, and whether they would intervene in response to 50 computer-presented clinical scenarios in which data on heart rate, systolic blood pressure, urine output, oxygen saturation, conscious level and oxygenation support were varied. Nurses were also presented with a protocol recommendation and also placed under time pressure for some of the scenarios. The ecological criterion was the predicted level of risk from the Modified Early Warning Score assessments of 232 UK acute care inpatients.

Results. Despite receiving identical information, nurses varied considerably in their risk assessments. The differences can be partly explained by variability in weightings given to information. Time and protocol recommendations were given more weighting than clinical information for key dichotomous choices such as classifying a patient as 'at risk' and deciding to intervene. Nurses' weighting of cues did not mirror the same information's contribution to risk in real patients. Nurses synthesized information in non-linear ways that contributed little to decisional accuracy. The low-moderate achievement (Ra) statistics suggests that nurses' assessments of risk were largely inaccurate; these assessments were applied consistently among 'patients' (scenarios). Critical care experience was statistically associated with estimates of risk, but not with the decision to intervene.

Conclusion. Nurses overestimated the risk and the need to intervene in simulated paper patients at risk of a critical event. This average response masked considerable variation in risk predictions, the need for action and the weighting afforded to the information they had available to them. Nurses did not make use of the linear reasoning required for accurate risk predictions in this task. They also failed to employ any unique knowledge that could be shown to make them more accurate. The influence of time pressure and protocol recommendations depended on the kind of judgement faced suggesting then that knowing more about the types of decisions nurses face may influence information use.

Relevance to clinical practice. Practice developers and educators need to pay attention to the quality of nurses' clinical experience as well as the quantity when developing judgement expertise in nurses. Intuitive unaided decision making in the assessment of risk may not be as accurate as supported decision making. Practice developers and educators should consider teaching nurses normative rules for revising probabilities (even subjective ones) such as Bayes' rule for diagnostic or assessment judgements and also that linear ways of thinking, in which decision support may help, may be useful for many choices that nurses face. Nursing needs to separate the rhetoric of 'holism' and 'expertise' from the science of predictive validity, accuracy and competence in judgement and decision making.

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Consumer Action commissioned Dr Paul Harrison, Deakin Business School, Deakin University and Marta Massi, School of Marketing and Communication, Lumsa University (Rome), to study the psychological aspects of one form of credit marketing – unsolicited credit card limit-increase offers (UCCLIOs). The researchers studied 21 UCCLIO letters – 17 provided by consumers and four provided by banks – and applied theories developed from previous research in the fields of marketing, consumer behavior, behavioural economics and cognitive psychology, to describe likely ways in which UCCLIO’s influenced consumer behavior and decision making. The researchers make some recommendations from a behavioural perspective based on their findings, and Consumer Action proposes how these findings might be applied to consumer policy.

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This thesis is about using appropriate tools in functional analysis arid classical analysis to tackle the problem of existence and uniqueness of nonlinear partial differential equations. There being no unified strategy to deal with these equations, one approaches each equation with an appropriate method, depending on the characteristics of the equation. The correct setting of the problem in appropriate function spaces is the first important part on the road to the solution. Here, we choose the setting of Sobolev spaces. The second essential part is to choose the correct tool for each equation. In the first part of this thesis (Chapters 3 and 4) we consider a variety of nonlinear hyperbolic partial differential equations with mixed boundary and initial conditions. The methods of compactness and monotonicity are used to prove existence and uniqueness of the solution (Chapter 3). Finding a priori estimates is the main task in this analysis. For some types of nonlinearity, these estimates cannot be easily obtained, arid so these two methods cannot be applied directly. In this case, we first linearise the equation, using linear recurrence (Chapter 4). In the second part of the thesis (Chapter 5), by using an appropriate tool in functional analysis (the Sobolev Imbedding Theorem), we are able to improve previous results on a posteriori error estimates for the finite element method of lines applied to nonlinear parabolic equations. These estimates are crucial in the design of adaptive algorithms for the method, and previous analysis relies on, what we show to be, unnecessary assumptions which limit the application of the algorithms. Our analysis does not require these assumptions. In the last part of the thesis (Chapter 6), staying with the theme of choosing the most suitable tools, we show that using classical analysis in a proper way is in some cases sufficient to obtain considerable results. We study in this chapter nonexistence of positive solutions to Laplace's equation with nonlinear Neumann boundary condition. This problem arises when one wants to study the blow-up at finite time of the solution of the corresponding parabolic problem, which models the heating of a substance by radiation. We generalise known results which were obtained by using more abstract methods.

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The overarching goal of this dissertation was to evaluate the contextual components of instructional strategies for the acquisition of complex programming concepts. A meta-knowledge processing model is proposed, on the basis of the research findings, thereby facilitating the selection of media treatment for electronic courseware. When implemented, this model extends the work of Smith (1998), as a front-end methodology, for his glass-box interpreter called Bradman, for teaching novice programmers. Technology now provides the means to produce individualized instructional packages with relative ease. Multimedia and Web courseware development accentuate a highly graphical (or visual) approach to instructional formats. Typically, little consideration is given to the effectiveness of screen-based visual stimuli, and curiously, students are expected to be visually literate, despite the complexity of human-computer interaction. Visual literacy is much harder for some people to acquire than for others! (see Chapter Four: Conditions-of-the-Learner) An innovative research programme was devised to investigate the interactive effect of instructional strategies, enhanced with text-plus-textual metaphors or text-plus-graphical metaphors, and cognitive style, on the acquisition of a special category of abstract (process) programming concept. This type of concept was chosen to focus on the role of analogic knowledge involved in computer programming. The results are discussed within the context of the internal/external exchange process, drawing on Ritchey's (1980) concepts of within-item and between-item encoding elaborations. The methodology developed for the doctoral project integrates earlier research knowledge in a novel, interdisciplinary, conceptual framework, including: from instructional science in the USA, for the concept learning models; British cognitive psychology and human memory research, for defining the cognitive style construct; and Australian educational research, to provide the measurement tools for instructional outcomes. The experimental design consisted of a screening test to determine cognitive style, a pretest to determine prior domain knowledge in abstract programming knowledge elements, the instruction period, and a post-test to measure improved performance. This research design provides a three-level discovery process to articulate: 1) the fusion of strategic knowledge required by the novice learner for dealing with contexts within instructional strategies 2) acquisition of knowledge using measurable instructional outcome and learner characteristics 3) knowledge of the innate environmental factors which influence the instructional outcomes This research has successfully identified the interactive effect of instructional strategy, within an individual's cognitive style construct, in their acquisition of complex programming concepts. However, the significance of the three-level discovery process lies in the scope of the methodology to inform the design of a meta-knowledge processing model for instructional science. Firstly, the British cognitive style testing procedure, is a low cost, user friendly, computer application that effectively measures an individual's position on the two cognitive style continua (Riding & Cheema,1991). Secondly, the QUEST Interactive Test Analysis System (Izard,1995), allows for a probabilistic determination of an individual's knowledge level, relative to other participants, and relative to test-item difficulties. Test-items can be related to skill levels, and consequently, can be used by instructional scientists to measure knowledge acquisition. Finally, an Effect Size Analysis (Cohen,1977) allows for a direct comparison between treatment groups, giving a statistical measurement of how large an effect the independent variables have on the dependent outcomes. Combined with QUEST's hierarchical positioning of participants, this tool can assist in identifying preferred learning conditions for the evaluation of treatment groups. By combining these three assessment analysis tools into instructional research, a computerized learning shell, customised for individuals' cognitive constructs can be created (McKay & Garner,1999). While this approach has widespread application, individual researchers/trainers would nonetheless, need to validate with an extensive pilot study programme (McKay,1999a; McKay,1999b), the interactive effects within their specific learning domain. Furthermore, the instructional material does not need to be limited to a textual/graphical comparison, but could be applied to any two or more instructional treatments of any kind. For instance: a structured versus exploratory strategy. The possibilities and combinations are believed to be endless, provided the focus is maintained on linking of the front-end identification of cognitive style with an improved performance outcome. My in-depth analysis provides a better understanding of the interactive effects of the cognitive style construct and instructional format on the acquisition of abstract concepts, involving spatial relations and logical reasoning. In providing the basis for a meta-knowledge processing model, this research is expected to be of interest to educators, cognitive psychologists, communications engineers and computer scientists specialising in computer-human interactions.

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Perspective taking, the main cognitive component of empathy, has a particularly important and complex role to play in the clinician-client relationship, particularly in mental health nursing. However, despite extensive investigation into the outcomes of this construct (e.g. sympathy, altruism), the process by which people take another's psychological point of view has received comparatively little attention. The purpose of this study was to investigate what the individual does when attempting to take the perspective of another person. The aims were to identify the specific strategies people used to accomplish this task, to consider how and why these strategies were chosen, and the relationship between the strategies and subsequent outcomes. Participants described an example of their own perspective-taking experience. Adopting an interpretive phenomenological approach, analysis resulted in the generation of several themes of direct relevance to both the perspective taking process and the wider empathic experience. Of particular importance were two superordinate themes, use of other-information and use of self-information. One significant subordinate theme (within use of selfinformation) to emerge was that of past experience, where the participant had experienced either (a) a similar role to that which they occupied in the present situation, or (b) a similar situation to that of the target person. Both of these experiences were determinants of how easy participants perceived the task of apprehending the target’s perspective. Within the wider empathic experience, themes included emotional manifestations (e.g. sympathy), as well as judgements of appropriate behaviours. Implications of findings when working in clinical and mental health settings are discussed.

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Modeling network traffic has been a critical task in the development of Internet. Attacks and defense are prevalent in the current Internet. Traditional network models such as Poisson-related models do not consider the competition behaviors between the attack and defense parties. In this paper, we present a microscopic competition model to analyze the dynamics among the nodes, benign or malicious, connected to a router, which compete for the bandwidth. The dynamics analysis demonstrates that the model can well describe the competition behavior among normal users and attackers. Based on this model, an anomaly attack detection method is presented. The method is based on the adaptive resonance theory, which is used to learn the model by normal traffic data. The evaluation shows that it can effectively detect the network attacks.

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Cognitive distortions have been afforded a key role in the offending behaviour of child sexual offenders. While the mechanisms underlying cognitive distortions are not fully understood, they are generally thought to reflect entrenched beliefs that distinguish child sexual offenders from other individuals. We investigated this hypothesis using a robust experimental technique called the lexical decision task. Child sexual offenders, offender controls, and non-offender controls completed a lexical decision task in which they responded to words that completed sentences in either an offence-supportive or nonoffence-supportive manner. Contrary to predictions, child sexual offenders did not respond faster to words that were consistent with offence-supportive beliefs, relative to controls. However, they did show accelerated recognition for word stems supporting external locus of control beliefs. These results highlight the need to use cognitive experimental methods to study child sexual offenders' beliefs, and the importance of investigating potential alternative drivers of cognitive distortions.

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Qualitative analysis of interviews with 22 child abusers found strong evidence for Ward and Keenan's (1999) proposal that there are five implicit theories in child abusers that account for the majority of their cognitive distortions/thinking errors. These implicit theories are: Child as a sexual being where children are perceived as being able to and wanting to engage in sexual activity with adults and also are not be harmed by such sexual contact; Nature of harm where the offender perceives that sexual activity does not cause harm (and may in fact be beneficial) to the child; Entitlement where the child abuser perceives that he is superior and more important than others: and hence is able to have sex with whoever, and whenever, he wants; Dangerous world where the offender perceives that that others are abusive and rejecting and he must fight to regain control; and Uncontrollable where the offender perceives the world as uncontrollable and hence he believes that circumstances are outside of his control. There was no evidence for any other type of implicit theory. Results of the study also indicated that there was a significant difference in terms of the endorsement of the Dangerous world implicit theory between participants reporting a history of child sexual abuse and those who did not. Offenders against male victims were significantly more likely to endorse the Child as a sexual being and Dangerous world implicit theories compared to men who had offended against female children.

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An innovative theory of the nature of cognition, the extended mind theory (EMT), has emerged recently in the cognitive science literature. According to the EMT, the boundaries of the mind extend beyond the boundaries of skull and skin, into the world beyond. My aim in this paper is to consider the practical implications of the EMT for therapists working with sex offenders' cognitive distortions. First, I provide an overview of the key assumptions of EMT. Secondly, I draw out the major implications of this novel theory of cognition for the assessment and treatment of cognitive distortions in sex offenders. Thirdly, to make the analysis more concrete, I discuss briefly how the treatment module of cognitive restructuring could proceed according to the EMT.