2,614 research outputs found

    Task analysis for error identification: Theory, method and validation

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    This paper presents the underlying theory of Task Analysis for Error Identification. The aim is to illustrate the development of a method that has been proposed for the evaluation of prototypical designs from the perspective of predicting human error. The paper presents the method applied to representative examples. The methodology is considered in terms of the various validation studies that have been conducted, and is discussed in the light of a specific case study

    Expert chess memory: Revisiting the chunking hypothesis

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    After reviewing the relevant theory on chess expertise, this paper re-examines experimentally the finding of Chase and Simon (1973a) that the differences in ability of chess players at different skill levels to copy and to recall positions are attributable to the experts' storage of thousands of chunks (patterned clusters of pieces) in long-term memory. Despite important differences in the experimental apparatus, the data of the present experiments regarding latencies and chess relations between successively placed pieces are highly correlated with those of Chase and Simon. We conclude that the 2-second inter-chunk interval used to define chunk boundaries is robust, and that chunks have psychological reality. We discuss the possible reasons why Masters in our new study used substantially larger chunks than the Master of the 1973 study, and extend the chunking theory to take account of the evidence for large retrieval structures (templates) in long-term memory

    WESTT (Workload, Error, Situational Awareness, Time and Teamwork): An analytical prototyping system for command and control

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    Modern developments in the use of information technology within command and control allow unprecedented scope for flexibility in the way teams deal with tasks. These developments, together with the increased recognition of the importance of knowledge management within teams present difficulties for the analyst in terms of evaluating the impacts of changes to task composition or team membership. In this paper an approach to this problem is presented that represents team behaviour in terms of three linked networks (representing task, social network structure and knowledge) within the integrative WESTT software tool. In addition, by automating analyses of workload and error based on the same data that generate the networks, WESTT allows the user to engage in the process of rapid and iterative “analytical prototyping”. For purposes of illustration an example of the use of this technique with regard to a simple tactical vignette is presented

    Why are Prices Sticky? Evidence from Business Survey Data

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    This paper offers new insights on the price setting behaviour of German retail firms using a novel dataset that consists of a large panel of monthly business surveys from 1991-2006. The firm-level data allows matching changes in firms' prices to several other firm-characteristics. Moreover, information on price expectations allow analyzing the determinants of price updating. Using univariate and bivariate ordered probit specifications, empirical menu cost models are estimated relating the probability of price adjustment and price updating, respectively, to both time- and state- dependent variables. First, results suggest an important role for state-dependence; changes in the macroeconomic and institutional environment as well as firm-specific factors are significantly related to the timing of price adjustment. These findings imply that price setting models should endogenize the timing of price adjustment in order to generate realistic predictions concerning the transmission of monetary policy. Second, an analysis of price expectations yields similar results providing evidence in favour of state-dependent sticky plan models. Third, intermediate input cost changes are among the most important determinants of price adjustment suggesting that pricing models should explicitly incorporate price setting at different production stages. However, the results show that adjustment to input cost changes takes time indicating "additional stickiness" at the last stage of processing

    Obtaining archaeointensity data from British Neolithic pottery: A feasibility study

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    YesThere is a significant lack of geomagnetic field strength (archaeointensity) measurements for many archaeological time periods in the United Kingdom (UK). This not only makes past geomagnetic secular variation difficult to model but also limits the development of archaeointensity dating. This paper presents the first archaeointensity study on UK Neolithic material. In this study, twenty-five sherds of Neolithic Grooved Ware pottery from the Ness of Brodgar, Orkney, UK, some with direct radiocarbon dates, were subjected to a full archaeomagnetic investigation with the aim of increasing the amount of archaeointensity data for the UK. Both thermal Thellier and microwave palaeointensity experiments were used to determine which technique would be most suitable for British Neolithic pottery. Three successful archaeointensity results between 35 and 40μT were obtained using thermal Thellier method, which is consistent with the limited data available within a 15° radius and geomagnetic field model predictions from the same time. We separated the results into four different types with an intention of explaining the behaviours that determine the likelihood of achieving an acceptable archaeointensity estimate. The feasibility of obtaining geomagnetic field strength information during the UK Neolithic from ceramics has been demonstrated and the results provide a solid basis for improving our knowledge of geomagnetic secular variation during archaeological time in Britain.The Andy Jagger Fund, University of Bradford, for supporting the stay at the University of Liverpool and Crafoord Grant, Sweden, No. 20160763. The radiocarbon dates were funded by AHRC NF/2017/2/7

    The Impact of Sectoral Minimum Wage Laws on Employment, Wages and Hours of Work in South Africa

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    This paper attempts to investigate the impact of sectoral wage laws in South Africa. Specifically, we examine the impact of minimum wage laws promulgated in the Retail, Domestic work, Forestry, Security, and Taxi sectors using 15 waves of biannual Labour Force Survey data for the 2000-2007 period

    A meta-analysis of the drive for muscularity's relationships with exercise behaviour, disordered eating, supplement consumption, and exercise dependence

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    We examined the drive for muscularity's (DFM) relationships with exercise behaviour, disordered eating, supplement consumption, and exercise dependence in males. By searching electronic databases, manually reviewing journal tables of contents and retrieved article reference lists, and corresponding with leading researchers, we identified 77 studies. A random effects model was applied to perform analyses and we adjusted results for possible publication bias. The average effect sizes (r) the DFM had with weight training (.31), non-weight training (.11), disordered eating (.30), supplement consumption (.36), and exercise dependence (.43) were significant (P < .05). The relationship between the attitudes and behavioural subscales of the DFM Scale (r = .47) was significant (P < .001). For supplement consumption, moderator analysis indicated that r varied significantly for questionnaire type and participant status (student versus non-student, P < .01). The small to moderate relationships indicate the value of adopting theoretical perspectives allowing the examination of the DFM's role in predicting exercise and dietary behaviour within a broader psychosocial context. Most researchers have studied these relationships in isolation. The relationship between the two DFM subscales implies that the questionnaire total score may better represent a commitment to muscularity rather than a drive per se

    Less Adaptive or More Maladaptive? A Meta-analytic Investigation of Procrastination and Coping

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    Despite the theoretical and empirical accounts of trait procrastination as reflecting avoidance of aversive tasks as a means of mood repair, research documenting its links to coping is scarce and inconsistent. There is also little if any research to date examining whether coping strategies might explain the procrastination-stress relationship. The current research aimed to address these issues by integrating current research on procrastination and coping with our own data into a first meta-analysis of the associations of procrastination with adaptive and maladaptive coping and then testing the potential role of coping for understanding the procrastination-stress relationship. In Study 1, a literature search yielded five published papers and three theses, which were supplemented by seven unpublished data sets comprising 15 samples (N=4357). Meta-analyses revealed that procrastination was positively associated with maladaptive coping (average r=.31) and negatively associated with adaptive coping (average r=-.24). In Study 2, a meta-analysis of the indirect effects through coping across four samples revealed that the average indirect effects for maladaptive but not adaptive coping explained the link between procrastination and stress. These findings expand the nomological network of procrastination and highlight the role of maladaptive coping for understanding procrastinators' stress

    The effect of the national minimum wage on the UK small business sector : a geographical analysis

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    A national minimum wage (NMW) was introduced into the United Kingdom in 1999 as part of New Labour's active labour-market approach. The level has been uprated on several occasions since then. Most research suggests that the NMW has benefited low-paid workers while having little adverse impact on employment levels. This paper explores the regional impact of the NMW on the small business sector, using data from the Federation of Small Businesses' biennial survey, the largest business survey in the United Kingdom. Overall, just over 21% of businesses with employees uprated employees and just under 10% of employees have benefited from pay uprates. The impact has varied across industries, with the greatest effects in the hotels and catering sector. In general, affected businesses have anticipated that they would be able to absorb the costs, although in some cases at the expense of a slight decline in profitability. The impact of the NMW also varies across the regions, having the least impact in London and the South East and the greatest impact in the 'north'. In the northern regions, businesses are less able to absorb the increased costs and more likely to respond by increasing prices. This has potential implications for the competitiveness of small and medium-sized enterprises in these regions, which is more likely to be based around price and cost advantages than their counterparts in the south. The Low Pay Commission therefore should give greater attention to the geographical impacts of the NMW in its evaluation and when proposing future increases in the rate
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