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Complex Task (complex + task)
Selected AbstractsJob completion prediction using case-based reasoning for Grid computing environmentsCONCURRENCY AND COMPUTATION: PRACTICE & EXPERIENCE, Issue 9 2007Lilian Noronha Nassif Abstract One of the main focuses of Grid computing is solving resource-sharing problems in multi-institutional virtual organizations. In such heterogeneous and distributed environments, selecting the best resource to run a job is a complex task. The solutions currently employed still present numerous challenges and one of them is how to let users know when a job will finish. Consequently, reserve in advance remains unavailable. This article presents a new approach, which makes predictions for job execution time in Grid by applying the case-based reasoning paradigm. The work includes the development of a new case retrieval algorithm involving relevance sequence and similarity degree calculations. The prediction model is part of a multi-agent system that selects the best resource of a computational Grid to run a job. Agents representing candidate resources for job execution make predictions in a distributed and parallel manner. The technique presented here can be used in Grid environments at operation time to assist users with batch job submissions. Experimental results validate the prediction accuracy of the proposed mechanisms, and the performance of our case retrieval algorithm. Copyright © 2006 John Wiley & Sons, Ltd. [source] Dynamics and function of intron sequences of the wingless gene during the evolution of the Drosophila genusEVOLUTION AND DEVELOPMENT, Issue 5 2004J. Costas Summary To understand the function and evolution of genes with complex patterns of expression, such as the Drosophila wingless gene, it is essential to know how their transcription is regulated. However, extracting the relevant regulatory information from a genome is still a complex task. We used a combination of comparative genomics and functional approaches to identify putative regulatory sequences in two introns (1 and 3) of the wingless gene and to infer their evolution. Comparison of the sequences obtained from several Drosophila species revealed colinear and well-conserved sequence blocks in both introns. Drosophila willistoni showed a rate of evolution, in both introns, faster than expected from its phylogenetic position. Intron 3 appeared to be composed of two separate modules, one of them lost in the willistoni group. We tested whether sequence conservation in noncoding regions is a reliable indicator of regulatory function and, if this function is conserved, by analyzing D. melanogaster transgenic reporter lines harboring intron 3 sequences from D. melanogaster (Sophophora subgenus) and the species from the Drosophila subgenus presenting the most divergent sequence, D. americana. The analysis indicated that intron 3 contains pupal enhancers conserved during the evolution of the genus, despite the fact that only 30% of the D. melanogaster intron 3 sequences lie in conserved blocks. Additional analysis of D. melanogaster transgenic reporter lines harboring intron 3 sequences from D. willistoni revealed the absence of an abdomen-specific expression pattern, probably due to the above-mentioned loss of a regulatory module in this species. [source] Knowledge-based treatment planning for adolescent early intervention of mental healthcare: a hybrid case-based reasoning approachEXPERT SYSTEMS, Issue 4 2007W.M. Wang Abstract: Treatment planning is a crucial and complex task in the social services industry. There is an increasing need for knowledge-based systems for supporting caseworkers in the decision-making of treatment planning. This paper presents a hybrid case-based reasoning approach for building a knowledge-based treatment planning system for adolescent early intervention of mental healthcare. The hybrid case-based reasoning approach combines aspects of case-based reasoning, rule-based reasoning and fuzzy theory. The knowledge base of case-based reasoning is a case base of client records consisting of documented experience while that for rule-based reasoning is a set of IF,THEN rules based on the experience of social service professionals. Fuzzy theory is adopted to deal with the uncertain nature of treatment planning. A prototype system has been implemented in a social services company and its performance is evaluated by a group of caseworkers. The results indicate that hybrid case-based reasoning has an enhanced performance and the knowledge-based treatment planning system enables caseworkers to construct more efficient treatment planning in less cost and less time. [source] Quantitative analysis of essential oils: a complex taskFLAVOUR AND FRAGRANCE JOURNAL, Issue 6 2008Carlo Bicchi Abstract This article provides a critical overview of current methods to quantify essential oil components. The fields of application and limits of the most popular approaches, in particular relative percentage abundance, normalized percentage abundance, concentration and true amount determination via calibration curves, are discussed in detail. A specific paragraph is dedicated to the correct use of the most widely used detectors and to analyte response factors. A set of applications for each approach is also included to illustrate the considerations. Copyright © 2008 John Wiley & Sons, Ltd. [source] Occupational Knowledge and Practice amongst UK University Research AdministratorsHIGHER EDUCATION QUARTERLY, Issue 2 2009John Hockey With the exception of lecturing staff, research on occupational groups and cultures within the UK higher education system is relatively sparse. This paper focuses upon one specialist group, to-date under-researched but which plays a central role in contemporary higher education administration: graduate research administrators. This occupational group is of particular interest as its members administer and manage an increasing complex and key area of university life, which in many cases appears to span the putative occupational divide between ,academic' and ,administrative' work. Based upon qualitative interviews with 27 research administrators, and using some of Bourdieu's conceptual devices, the paper analyses particular kinds of informal occupational knowledge and practice, necessary in order effectively to ,do' the complex task of research administration in the pressurized environment of contemporary British higher education. [source] Multiple hypothesis evaluation in auditingACCOUNTING & FINANCE, Issue 3 2002Rajendra P. Srivastava In many audit tasks, auditors evaluate multiple hypotheses to diagnose the situation. Research suggests this is a complex task that individuals have difficulty performing. Further, there is little guidance in professional standards or literature dealing with the many complexities present in the audit environment. Using probability theory, this study derives the appropriate revision of likelihoods for multiple hypotheses given different realistic audit conditions. The analysis shows that the relationships among the hypotheses dramatically impact the use of audit evidence and the resulting pattern of probability revisions. We also identify testable hypotheses to guide future research and discuss practice implications regarding ways to improve the effectiveness of analytical procedures. [source] Virtual team collaboration: building shared meaning, resolving breakdowns and creating translucenceINFORMATION SYSTEMS JOURNAL, Issue 3 2009Pernille Bjørn Abstract Managing international teams with geographically distributed participants is a complex task. The risk of communication breakdowns increases due to cultural and organizational differences grounded in the geographical distribution of the participants. Such breakdowns indicate general misunderstandings and a lack of shared meaning between participants. In this paper, we address the complexity of building shared meaning. We examine the communication breakdowns that occurred in two globally distributed virtual teams by providing an analytical distinction of the organizational context as the foundation for building shared meaning at three levels. Also we investigate communication breakdowns that can be attributed to differences in lifeworld structures, organizational structures, and work process structures within a virtual team. We find that all communication breakdowns are manifested and experienced by the participants at the work process level; however, resolving breakdowns may require critical reflection at other levels. Where previous research argues that face-to-face interaction is an important variable for virtual team performance, our empirical observations reveal that communication breakdowns related to a lack of shared meaning at the lifeworld level often becomes more salient when the participants are co-located than when geographically distributed. Last, we argue that creating translucence in communication structures is essential for building shared meanings at all three levels. [source] Understanding the implementation of software process improvement innovations in software organizationsINFORMATION SYSTEMS JOURNAL, Issue 1 2004Karlheinz Kautz Abstract., The development of software is a complex task frequently resulting in unfinished projects, project overruns and system failures. Software process improvement (SPI) approaches have been promoted as a promising remedy for this situation. The organizational implementation of such approaches is a crucial issue and attempts to introduce SPI into software organizations often fail. This paper presents a framework to understand, and subsequently successfully perform, the implementation of SPI innovations in software organizations. The framework consists of three perspectives on innovation: an individualist, a structuralist and an interactive process perspective. Applied to SPI, they emphasize different aspects of implementing SPI innovations. While the first focuses on leadership, champions and change agents, the second focuses on organization size, departmental and task differentiation and complexity, and the third perspective views the contents of the innovation, the social context and process of the implementation as related in an interactive process. We demonstrate the framework's applicability through two cases. We show that the three perspectives supplement each other and together provide a deeper understanding of the implementation process. Such understanding is crucial for the successful uptake of SPI approaches in software organizations. [source] Supramolecular Crystal Engineering at the Solid,Liquid Interface from First Principles: Toward Unraveling the Thermodynamics of 2D Self-AssemblyADVANCED MATERIALS, Issue 13 2009Carlos-Andres Palma Abstract The formation of highly ordered 2D supramolecular architectures self-assembled at the solid,solution interfaces is subject to complex interactions between the analytes, the solvent, and the substrate. These forces have to be mastered in order to regard self-assembly as an effective bottom-up approach for functional-device engineering. At such interfaces, prediction of the thermodynamics governing the formation of spatially ordered 2D arrangements is far from being fully understood, even for the physisorption of a single molecular component on the basal plane of a flat surface. Two recent contributions on controlled polymorphism and nanopattern formation render it possible to gain semi-quantitative insight into the thermodynamics of physisorption at interfaces, paving the way towards 2D supramolecular crystal engineering. Although in these two works different systems have been chosen to tackle such a complex task, authors showed that the chemical design of molecular building blocks is not the only requirement to fulfill when trying to preprogram self-assembled patterns at the solid,liquid interface. [source] A contingency approach to resource-creation processesINTERNATIONAL JOURNAL OF MANAGEMENT REVIEWS, Issue 4 2006Cliff Bowman The resource-based view has provided valuable insights into sources of competitive advantage, but little attention has been paid to the processes of resource creation. To address this shortcoming, this paper reviews the strategy process literature, explaining the theoretical positions and assumptions that underpin different types of process. It then examines the mechanisms by which resources have been found to be created; luck, resource picking, internal development and alliances. Next, a series of resource-creation pathways that illustrate the different routes firm inputs might take on the way to becoming unique and valuable resources is developed. These pathways are also discussed in terms of the strategy processes through which they are developed, and the appropriate resource-creation processes. The review is then extended with the introduction of two contingent variables , task complexity and environmental stability , and the resource-creation processes that are congruent with different combinations of these variables are explored. From this review, one is able to identify the combination of complex task and stable environment likely to be the most conducive to resource creation. Finally, the paper explores opportunities that firms might have to engineer stability and complexity in some parts of their operations with the aim of developing a resource-based advantage. [source] Understanding the volunteer market: the what, where, who and why of volunteeringINTERNATIONAL JOURNAL OF NONPROFIT & VOLUNTARY SECTOR MARKETING, Issue 3 2002Helen Bussell Although the work of the voluntary sector is growing, the number of people volunteering is not increasing at a comparable rate. This paper argues that the key to an organisation's success in recruiting and retaining its volunteers is to have an understanding of its target group. As a means to developing this understanding the paper reviews the prior research on volunteering and outlines the current situation in the voluntary sector with regard to the donation of time. The review shows that those who volunteer are an extremely diverse group, active in a wide variety of contexts. This makes the definition of a volunteer a more complex task than one would expect. It also demonstrates that individuals and organisations may volunteer for reasons other than purely altruistic motives. Finally, the paper identifies gaps in this area of research and presents topics for further research. Copyright © 2002 Henry Stewart Publications [source] Producers' complex risk management choicesAGRIBUSINESS : AN INTERNATIONAL JOURNAL, Issue 1 2008Joost M.E. Pennings Producers have a wide variety of risk management instruments available, making their choice(s) complex. The way producers deal with this complexity can vary and may influence the impact that the determinants, such as risk aversion, have on their choices. A recently developed choice bracketing framework recognizes that producers are unable to evaluate all alternatives simultaneously and that to manage a complex task, they often group or bracket individual alternatives and their consequences together in choice sets. Data on 1,105 U.S. producers show that producers do not use all available combinations of risk management tools and that the influence of the determinants of producer's risk management decisions are not necessarily the same across risk management strategies within and across bracketing levels. The findings may help resolve puzzling results on the role that well-known determinants of risk management behavior have on producers' choices, extending knowledge on producers' risk management behavior. Further, the findings have managerial implications for policy makers and agribusiness companies that provide risk management services. [EconLit citations: M000, G1000, Q130] © 2008 Wiley-Liss, Inc. [source] The public affairs of internationalisation: balancing pressures from multiple environmentsJOURNAL OF PUBLIC AFFAIRS, Issue 1 2004Rian Drogendijk Abstract Managing public affairs is a very complex task for internationalising firms. Multinational companies (MNCs) are not only single organisations operating in a global environment, but at the same time they are collections of interlinked subsidiaries that operate in a diversity of national environments. This paper investigates conceptually how subsidiaries of MNCs build relationships with internal MNC counterparts and external market and non-market actors as they mature and build resources and capabilities. It shows that, in order to understand the dynamics of public affairs management in MNCs, we need to study the relationships of MNCs and their subsidiaries with a variety of stakeholders in the internal and external environment of the organisation. Copyright © 2004 Henry Stewart Publications [source] DEVELOPMENT AND EVALUATION OF MULTIPLE-OBJECTIVE DECISION-MAKING METHODS FOR WATERSHED MANAGEMENT PLANNING,JOURNAL OF THE AMERICAN WATER RESOURCES ASSOCIATION, Issue 2 2002France Lamy ABSTRACT: Making decisions for environmental management is a complex task due to the multiplicity and diversity of technological choices. Furthermore, the exploitation of natural resources and the preservation of the natural environment imply objectives that are often in conflict within a sustainable development paradigm. Managers and other decision makers require techniques to assist them in understanding strategic decision making. This paper illustrates the use of a multiple-objective decision-making methodology and an integrative geographical information system-based decision-making tool developed to help watershed councils prioritize and evaluate restoration activities at the watershed level. Both were developed through a multidisciplinary approach. The decision-making tool is being applied in two watersheds of Oregon's Willamette River Basin. The results suggest that multiple-objective methods can provide a valuable tool in analyzing complex watershed management issues. [source] Understanding Materials Processing LasersLASER TECHNIK JOURNAL, Issue 5 2009A Comprehensive Overview Covering the Capabilities, Applicability of the Major Systems A decade ago, flowing gas CO2 lasers dominated the market for materials processing applications, such as cutting, welding and marking of metals and organics. However, over the past few years, new laser technologies have emerged that give the materials processor more options in choosing a laser source. Specifically these developments include the introduction of higher power sealed CO2 lasers, the advent of fiber lasers, and improvements in the brightness of direct diode laser systems. The result is that choosing the right laser for a specific application is now a more complex task than in the past. This article reviews the technology and capabilities of all these laser types and provides guidance on identifying the optimal source for a specific need. [source] Complexity as a constraint on firm expansion within and across industriesMANAGERIAL AND DECISION ECONOMICS, Issue 6 2009Thomas Hutzschenreuter With this paper, we want to shed light on factors influencing a firm's rate of expansion. We argue that expansion is a complex task and complexity associated with expansion projects in one period can negatively impact rate of expansion in the following period. Moreover, we argue that firm portfolio complexity also slows down further expansion. Using longitudinal data on the expansion path of 91 German companies, we show that added product scope of expansion and degree of internationalization characterizing expansion in one period as well as level of product and international diversity have a significant impact on slowing down rate of expansion in the subsequent period. Copyright © 2008 John Wiley & Sons, Ltd. [source] Mass spectrometry-based metabolomicsMASS SPECTROMETRY REVIEWS, Issue 1 2007Katja Dettmer Abstract This review presents an overview of the dynamically developing field of mass spectrometry-based metabolomics. Metabolomics aims at the comprehensive and quantitative analysis of wide arrays of metabolites in biological samples. These numerous analytes have very diverse physico-chemical properties and occur at different abundance levels. Consequently, comprehensive metabolomics investigations are primarily a challenge for analytical chemistry and specifically mass spectrometry has vast potential as a tool for this type of investigation. Metabolomics require special approaches for sample preparation, separation, and mass spectrometric analysis. Current examples of those approaches are described in this review. It primarily focuses on metabolic fingerprinting, a technique that analyzes all detectable analytes in a given sample with subsequent classification of samples and identification of differentially expressed metabolites, which define the sample classes. To perform this complex task, data analysis tools, metabolite libraries, and databases are required. Therefore, recent advances in metabolomics bioinformatics are also discussed. © 2006 Wiley Periodicals, Inc., Mass Spec Rev 26:51,78, 2007 [source] Melanocortin ligands: 30 years of structure,activity relationship (SAR) studiesMEDICINAL RESEARCH REVIEWS, Issue 3 2004Jerry Ryan Holder Abstract The challenge of peptide and peptidomimetic research is the development of methods and techniques to improve the biological properties of native peptides and to convert peptide ligands into non-peptide compounds. Improved biological properties of peptides includes enhancement of stability, potency, and receptor selectivity, for both in vivo and in vitro applications. The design of a ligand with specific activity and desired biological properties is a complex task, and, to accomplish this objective, knowledge about putative interactions between a ligand and the corresponding receptor will be valuable. This includes interactions for both the binding and signal transduction processes. Structure,activity relationship (SAR) studies involve systematic modification of a lead peptide and are designed to provide insight into potential interactions involved in the formation of the ligand,receptor complex. It is desirable to have knowledge about both favorable and unfavorable processes that may occur in putative ligand,receptor interactions that result in either receptor stimulation or inhibition. Herein, we discuss various SAR studies that have involved melanocortin peptides over three decades and the information these studies have provided to the melanocortin field. © 2004 Wiley Periodicals, Inc. Med Res Rev, 24, No. 3, 325,356, 2004 [source] Relationship between health services outcomes and social and economic outcomes in workplace injury and disease: Data sources and methods,AMERICAN JOURNAL OF INDUSTRIAL MEDICINE, Issue 3 2001Cam Mustard ScD Abstract Background Understanding the mediating role of health care in mitigating social, economic and occupational role disability is a complex task. Methods No single method of research will be successful in addressing all elements of this NORA research priority area. In this paper, we argue that research methods are needed which have the following components: (1) the detailed measurement of therapeutic intervention and the impacts of this intervention on clinical and functional health status using study designs which rule out competing explanations, (2) a longitudinal follow-up component which measures social, economic, and occupational role function following the conclusion of therapy, and (3) a commitment to execute studies across multiple settings to observe the variations in health care and in social and occupational role function that arise as a result of differences in labor market factors and employer and government policies. Conclusions More comprehensive portraits of the longitudinal trajectory of individual workers, social, economic and occupational role function following an occupational injury or illness will have significance for a large number of policy sectors. Am. J. Ind. Med. 40:335,343, 2001. © 2001 Wiley-Liss, Inc. [source] Performance prediction of concentrator solar cells and modules from dark I,V characteristicsPROGRESS IN PHOTOVOLTAICS: RESEARCH & APPLICATIONS, Issue 3 2003I. Antón The indoor performance of concentrator solar cells and modules at operating conditions is a complex task, owing to the required illumination and temperature conditions, and even more so during extensive procedures, such as on a production line. The solution proposed throughout this paper consists of predicting the illumination I,V characteristic of the solar cells, with the dark I,V curve and the photogenerated current as the only input data. As well as this, the technology-dependent components of the series resistance are obtained from the dark characteristics for quality control. Theory and experiments on several types of concentrator cell have been carried out to validate the method. The equipment to be used on a production line has been developed by IES and used by BP Solar to test up to 25 000 cells and 2000 modules for the 480,kWp power plant using the EUCLIDESTM concentrator. Copyright © 2003 John Wiley & Sons, Ltd. [source] Three Versions of StokerPUBLIC ADMINISTRATION, Issue 2 2005Kevin Orr This article offers an assessment of the writings of Professor Gerry Stoker of Manchester and examines the main themes and messages of his work as it has related to both academics and practitioners. It examines the controversial nature of Stoker's output which has provoked the charge of 'betraying' local government, and suggests that reading Stoker's work is a more complex task than perhaps his fiercest critics would allow. It argues that there is more than one way in which Stoker's contribution can be interpreted and that there are, in ways which mirror his own pluralistic approach to political science, a number of 'versions of Stoker' which can be advanced based on a close reading of his work. This article explores three of these. [source] The use of a geographical information system for land-based aquaculture planningAQUACULTURE RESEARCH, Issue 4 2002Ian McLeod Abstract Site selection for aquaculture planning is a complex task involving the identification of areas that are economically, socially and environmentally suitable, available to aquaculture and commercially practicable. This paper reports upon a study into the use of a geographic information system (GIS) to assist in aquaculture planning. Using a case study in the site selection for land-based shrimp farming within the Australian coastal zone, we demonstrate that a GIS has potential to assist aquaculture planning. Our analysis is based on a sequential, two-stage approach. The first stage eliminates the grossly unsuitable portion of the study area through a preselection with low resolution, cheap and easily available data. The second stage then focuses on and ranks the remaining area using high resolution, possibly more expensive data. Finally, we use the GIS to present the results of the analysis in an easily accessible form. [source] Use of the Perceive, Recall, Plan and Perform System of Task Analysis for persons with schizophrenia: A preliminary studyAUSTRALIAN OCCUPATIONAL THERAPY JOURNAL, Issue 3 2009Ginette Aubin Background/aim:,Task analysis that targets information processing skills is an essential tool to understanding difficulties encountered by people with schizophrenia in their daily activities. The purpose of this preliminary study was to explore the use of the Perceive, Recall, Plan and Perform (PRPP) System of Task Analysis for this clientele. The specific objectives were to describe information processing difficulties as measured by the PRPP and to examine preliminary evidence of construct validity and interrater reliability. Methods:,In the first part of this study, 10 participants with schizophrenia living in the community were assessed using the PRPP during both a simple and a complex meal preparation task. Community functioning was measured using the Independent Living Skills Survey. In the second part, interrater reliability was appraised using three trained raters, who scored 15 participants preparing the complex meal preparation task. Results:,Analysis of performance demonstrates that people with schizophrenia have difficulties especially in the Perceive and Plan quadrants of the PRPP and are more challenged in the complex task. The PRPP total score for the complex task is strongly related to the community functioning score. Results indicate good interrater reliability for the PRPP total score and moderate interrater reliability for the quadrant scores. Conclusion:,Despite the small sample size, results from this preliminary study support the use of the PRPP System of Task Analysis to further explore the impact cognitive deficits have on daily task performance and thus on community functioning in people with schizophrenia. [source] Untersuchung verschiedener Bodenmodelle zur Berechnung von Fundamentplatten im Rahmen von FEM-LösungenBAUTECHNIK, Issue 5 2004Christian Barth Prof. Dr.-Ing. #Die wirklichkeitsnahe Abbildung von Bauwerk-Boden-Wechselwirkungen in Finite-Elemente-Programmen ist ungeachtet des gegenwärtig hohen Entwicklungsstands der verfügbaren Software eine nicht zu unterschätzende Aufgabe. Einerseits erfordert die richtige Einbindung des Bodenmodells in die FE-Berechnung viele Überlegungen und Kenntnisse, andererseits sind die in der Software implementierten Bodenmodelle aber für den Anwender nicht immer in ihrer gesamten Komplexität durchschaubar. Anhand alltäglicher Aufgabenstellungen werden vier verschiedene häufig verwendete und in FEM-Lösungen implementierte Bodenmodelle unterschiedlicher Softwarehersteller untersucht. Die erzielten Ergebnisse werden gegenübergestellt, und der Versuch einer Bewertung wird vorgenommen. Investigation of different models for the analysis of foundation slabs with reference to FEM solutions. The realistic interaction between a foundation slab and the soil in FE-programs is a formidable and complex task, despite the availability of sophisticated software solutions. On the one hand the incorporation of the slab-soil behaviour into conventional software programs requires considerable experience and thought and, on the other hand, existing software programs are often difficult to understand because of their complexity. Using common design examples four different models, which arc frequently used in FE solutions, are applied in this study. The results are compared and critically examined. [source] 4221: The initial consultation: when should non-organic visual loss be suspected?ACTA OPHTHALMOLOGICA, Issue 2010W SPILEERS Purpose When a patient reports visual loss and the doctor can not immediately find the etiology, a non-organic visual loss has to be excluded. Methods Different testing methods can be of value in deciding on organic versus non-organic visual loss: visual acuity and visual field measurements, pupillary reflexes, electrophysiologic testing, imaging techniques, ... Results The value of these different methods will be discussed and illustrated Conclusion The investigation of possible non-organic visual loss is a complex task [source] Development of motor speed and associated movements from 5 to 18 yearsDEVELOPMENTAL MEDICINE & CHILD NEUROLOGY, Issue 3 2010THEO GASSER PHD Aim, To study the development of motor speed and associated movements in participants aged 5 to 18 years for age, sex, and laterality. Method, Ten motor tasks of the Zurich Neuromotor Assessment (repetitive and alternating movements of hands and feet, repetitive and sequential finger movements, the pegboard, static and dynamic balance, diadochokinesis) were administered to 593 right-handed participants (286 males, 307 females). Results, A strong improvement with age was observed in motor speed from age 5 to 10, followed by a levelling-off between 12 and 18 years. Simple tasks and the pegboard matured early and complex tasks later. Simple tasks showed no associated movements beyond early childhood; in complex tasks associated movements persisted until early adulthood. The two sexes differed only marginally in speed, but markedly in associated movements. A significant laterality (p<0.001) in speed was found for all tasks except for static balance; the pegboard was most lateralized, and sequential finger movements least. Associated movements were lateralized only for a few complex tasks. We also noted a substantial interindividual variability. Interpretation, Motor speed and associated movements improve strongly in childhood, weakly in adolescence, and are both of developmental relevance. Because they correlate weakly, they provide complementary information. [source] Maturation of action monitoring from adolescence to adulthood: an ERP studyDEVELOPMENTAL SCIENCE, Issue 6 2005Alexandra M. Hogan This study investigated the development of the frontal lobe action-monitoring system from late childhood and adolescence to early adulthood using ERP markers of error processing. Error negativity (ERN) and correct response negativity (CRN) potentials were recorded while adolescents and adults (aged 12,22 years, n = 23) performed two forced-choice visual reaction time tasks of differing complexity. Significant age differences were seen for behavioural and ERP responses to complex (infrequent, incompatible) trials: adolescents elicited an error negativity of reduced magnitude compared with adults. Furthermore, in contrast to adults, adolescents showed a non-significant differentiation between response-locked ERP components elicited by correct (CRN) and error responses (ERN). Behaviourally, adolescents corrected fewer errors in incompatible trials, and with increasing age there was greater post-error slowing. In conclusion, the neural systems underlying action-monitoring continue to mature throughout the second decade of life, and are associated with increased efficiency for fast error detection and correction during complex tasks. [source] Assessing Differential Item Functioning in Performance Assessment: Review and RecommendationsEDUCATIONAL MEASUREMENT: ISSUES AND PRACTICE, Issue 3 2000Randall D. Penfield How can we best extend DIF research to performance assessment? What are the issues and problems surrounding studies of DIF on complex tasks? What appear to be the best approaches at this time? [source] The effects of one night of sleep deprivation on known-risk and ambiguous-risk decisionsJOURNAL OF SLEEP RESEARCH, Issue 3 2007BENJAMIN S. MCKENNA Summary Sleep deprivation has been shown to alter decision-making abilities. The majority of research has utilized fairly complex tasks with the goal of emulating 'real-life' scenarios. Here, we use a Lottery Choice Task (LCT) which assesses risk and ambiguity preference for both decisions involving potential gains and those involving potential losses. We hypothesized that one night of sleep deprivation would make subjects more risk seeking in both gains and losses. Both a control group and an experimental group took the LCT on two consecutive days, with an intervening night of either sleep or sleep deprivation. The control group demonstrated that there was no effect of repeated administration of the LCT. For the experimental group, results showed significant interactions of night (normal sleep versus total sleep deprivation, TSD) by frame (gains versus losses), which demonstrate that following as little as 23 h of TSD, the prototypical response to decisions involving risk is altered. Following TSD, subjects were willing to take more risk than they ordinarily would when they were considering a gain, but less risk than they ordinarily would when they were considering a loss. For ambiguity preferences, there seems to be no direct effect of TSD. These findings suggest that, overall, risk preference is moderated by TSD, but whether an individual is willing to take more or less risk than when well-rested depends on whether the decision is framed in terms of gains or losses. [source] Beyond the Test: L2 Dynamic Assessment and the Transcendence of Mediated LearningMODERN LANGUAGE JOURNAL, Issue 3 2007MATTHEW E. POEHNER A major preoccupation in assessment is connecting examinees' performance in assessment and nonassessment contexts. This preoccupation has traditionally been framed in terms of generalizability. This article reconceptualizes this problem from a qualitatively different perspective on human abilities and their development, namely, the Sociocultural Theory of Mind outlined in the work of Vygotsky (1986, 1998). From this perspective, assessment occurs not in isolation from instruction but as an inseparable feature of it. Assessment and instruction are dialectically integrated as a single activity that seeks to understand development by actively promoting it. This pedagogical approach, known as Dynamic Assessment (DA), challenges the widespread acceptance of independent performance as the privileged indicator of individuals' abilities and calls for assessors to abandon their role as observers of learner behavior in favor of a commitment to joint problem solving aimed at supporting learner development. In DA, the traditional goal of producing generalizations from a snapshot of performance is replaced by ongoing intervention in development. Following Vygtosky's argument that true development goes beyond improvement on a given assessment task, DA practitioners have devised a method known as transcendence (TR), in which they collaborate with learners on increasingly complex tasks. In this article, transcendence in the second language (L2) domain is illustrated with examples of advanced learners of French composing oral narratives with support from a mediator. The article concludes with recommendations for future research on TR in L2 development. [source] | |||||||||||||||||||||||||||||||