724 research outputs found

    Program Predicts Time Courses of Human/Computer Interactions

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    CPM X is a computer program that predicts sequences of, and amounts of time taken by, routine actions performed by a skilled person performing a task. Unlike programs that simulate the interaction of the person with the task environment, CPM X predicts the time course of events as consequences of encoded constraints on human behavior. The constraints determine which cognitive and environmental processes can occur simultaneously and which have sequential dependencies. The input to CPM X comprises (1) a description of a task and strategy in a hierarchical description language and (2) a description of architectural constraints in the form of rules governing interactions of fundamental cognitive, perceptual, and motor operations. The output of CPM X is a Program Evaluation Review Technique (PERT) chart that presents a schedule of predicted cognitive, motor, and perceptual operators interacting with a task environment. The CPM X program allows direct, a priori prediction of skilled user performance on complex human-machine systems, providing a way to assess critical interfaces before they are deployed in mission contexts

    Computational Rationality: Linking Mechanism and Behavior Through Bounded Utility Maximization

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    We propose a framework for including information‐processing bounds in rational analyses. It is an application of bounded optimality (Russell & Subramanian, 1995) to the challenges of developing theories of mechanism and behavior. The framework is based on the idea that behaviors are generated by cognitive mechanisms that are adapted to the structure of not only the environment but also the mind and brain itself. We call the framework computational rationality to emphasize the incorporation of computational mechanism into the definition of rational action. Theories are specified as optimal program problems , defined by an adaptation environment, a bounded machine, and a utility function. Such theories yield different classes of explanation, depending on the extent to which they emphasize adaptation to bounds, and adaptation to some ecology that differs from the immediate local environment. We illustrate this variation with examples from three domains: visual attention in a linguistic task, manual response ordering, and reasoning. We explore the relation of this framework to existing “levels” approaches to explanation, and to other optimality‐based modeling approaches.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/106911/1/tops12086.pd

    A Bayesian model of how people search online consumer reviews

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    In this paper we describe a model of how people search online consumer reviews in service of purchasing decisions. The model is similar to other recent models of information seeking in that it updates estimates of products’ utilities using Bayesian inference. It is different, in that it stops seeking further information when the confidence that one of the alternatives is the best exceeds a threshold. Findings from a controlled experiment support the model by suggesting that high variance in review ratings causes people to seek more information

    A multinuclear solid state NMR, density functional theory and X-Ray diffraction study of hydrogen bonding in Group I hydrogen dibenzoates

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    An NMR crystallographic approach incorporating multinuclear solid state NMR (SSNMR), X-ray structure determinations and density functional theory (DFT) are used to characterise the H bonding arrangements in benzoic acid (BZA) and the corresponding Group I alkali metal hydrogen dibenzoates (HD) systems. Since the XRD data often cannot precisely confirm the proton position within the hydrogen bond, the relationship between the experimental SSNMR parameters and the ability of gauge included plane augmented wave (GIPAW) DFT to predict them becomes a powerful constraint that can assist with further structure refinement. Both the 1H and 13C MAS NMR methods provide primary descriptions of the H bonding via accurate measurements of the 1H and 13C isotropic chemical shifts, and the individual 13C chemical shift tensor elements; these are unequivocally corroborated by DFT calculations, which together accurately describe the trend of the H bonding strength as the size of the monovalent cation changes. In addition, 17O MAS and DOR NMR form a powerful combination to characterise the O environments, with the DOR technique providing highly resolved 17O NMR data which helps verify unequivocally the number of inequivalent O positions for the conventional 17O MAS NMR to process. Further multinuclear MAS and static NMR studies involving the quadrupolar 7Li, 39K, 87Rb and 133Cs nuclei, and the associated DFT calculations, provide trends and a corroboration of the H bond geometry which assist in the understanding of these arrangements. Even though the crystallographic H positions in each H bonding arrangement reported from the single crystal X-ray studies are prone to uncertainty, the good corroboration between the measured and DFT calculated chemical shift and quadrupole tensor parameters for the Group I alkali species suggest that these reported H positions are reliable

    The relevance of formal and nonformal primary education in relation to health, wellbeing and environmental awareness:Bangladeshi pupils’ perspectives in the rural contexts

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    Purpose: This article reports part of a study focusing on young people’s transition from the nonformal to the formal education sector, and explores how the experiences of children and young people in remote formal and nonformal schools affect their awareness of issues of health, well-being and the environment. One of the main objectives of Bangladeshi extensive nonformal primary education, run by nongovernmental organizations (NGOs) in parallel with the formal system, is to prepare children outside schools to enter or re-enter the formal education sector. The study addresses the issue of educational relevance from pupils’ perspectives and looking at the implications for pupil transition between these two sectors. Method: Interviews and observations of students and their classes were conducted in two contrasting rural high schools in different areas of Bangladesh, and their feeder primary schools. Results: Where formal primary graduates focus more in high school on learning from their textbooks, nonformal primary graduates aim to put their knowledge into practice in their day-to-day life on a range of critical issues. Conclusion: The results suggest an important contrast between nonformal and formal education sectors regarding students’ agency and knowledge of health and well-being, hygiene and environmental awareness in rural Bangladesh

    Effects of hyperlinks on navigation in virtual environments

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    Hyperlinks introduce discontinuities of movement to 3-D virtual environments (VEs). Nine independent attributes of hyperlinks are defined and their likely effects on navigation in VEs are discussed. Four experiments are described in which participants repeatedly navigated VEs that were either conventional (i.e. obeyed the laws of Euclidean space), or contained hyperlinks. Participants learned spatial knowledge slowly in both types of environment, echoing the findings of previous studies that used conventional VEs. The detrimental effects on participants' spatial knowledge of using hyperlinks for movement were reduced when a time-delay was introduced, but participants still developed less accurate knowledge than they did in the conventional VEs. Visual continuity had a greater influence on participants' rate of learning than continuity of movement, and participants were able to exploit hyperlinks that connected together disparate regions of a VE to reduce travel time

    Partnerships in pedagogy: Refocusing of classroom lenses

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    Current models of initial teacher training (ITT) in England include substantial elements of school-based experience developed in collaborative partnerships with local schools involving university tutors working with experienced classroom teachers. Balance in such partnerships has been characterised as trainees focusing on day-to-day pragmatics of working in classrooms whilst engaged in school experience, while their higher education institution (HEI) elements provide theoretical bases to underpin school based activities. Within such partnership arrangements, development of pedagogic beliefs and expertise is achieved by a complex network of experiences. Within the context of this paper this element of pedagogic development is shown to be less well supported than other aspects of trainee teachers' professional preparation. This paper, using cultural historical activity theory (CHAT), focuses on a small-scale research project in which mentor and trainee dialogue is examined. The paper concludes that CHAT analysis makes a valuable contribution to our understanding of how to resolve some of these issues within teacher training partnerships. © 2010 Association for Teacher Education in Europe
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