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Peer Reviewed
See detailComputerised method to measure asymetrical articular compression on digitised X-rays
Caudron, I; Henrotin, Yves ULg; Reginster, Jean-Yves ULg et al

in Rivista SIDI Proceedings 5th WEVA Congress (1st part) (1998)

Detailed reference viewed: 9 (0 ULg)
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See detailComputerised Tailored Testing: Structured and calibrated Item for Summative and Formative Evaluation
Leclercq, Dieudonné ULg

in European Journal of Education (1980), 15(3), 251-260

Advancements in educational testing, especially in the computerized construction of tests from item banks, are outlined and explained. It is suggested that these methods open the door to more ... [more ▼]

Advancements in educational testing, especially in the computerized construction of tests from item banks, are outlined and explained. It is suggested that these methods open the door to more individualized and more formative type of testing. [less ▲]

Detailed reference viewed: 27 (1 ULg)
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See detailComputerized adaptive and multi-stage testing with R
Yan, Duanli; Magis, David ULg

Conference (2016, February 19)

Computerized Adaptive Testing (CAT) has greatly improved the accuracy and efficiency of psychological testing for decades. Multistage Testing (MST) has received much of attention recently. MST is similar ... [more ▼]

Computerized Adaptive Testing (CAT) has greatly improved the accuracy and efficiency of psychological testing for decades. Multistage Testing (MST) has received much of attention recently. MST is similar to CAT such that it allows the adaptation of the difficulty of the test to the level of ability of a test taker. Specifically, in MST, items are interactively selected for each test taker, but rather than selecting individual items, groups of items are selected and the test is built in stages. Over the last decade, researchers have investigated ways for an MST to incorporate most of the advantages from CAT and linear testing, while minimize their disadvantages. These features include testing efficiency and accuracy, greater control of test content, more robust item review, as well as simplified test assembly and administration. Therefore, MST can be an effective compromise between CAT and linear testing, embedding features and benefits from both designs. Thus, MST becomes of more and more interest to researchers and practitioners as technology advances. This presentation will first provide a general overview of a multistage test (MST) design and its important concepts and processes. It will then present the latest development on CAT and MST using R, the mstR package. The presentation will also illustrate how to simulate MST administrations using mstR package, and discuss some practical issues and considerations for MST from design to applications. [less ▲]

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See detailComputerized Adaptive Testing
Braeken, Johan; Magis, David ULg; Stillwell, David

Scientific conference (2016, April 25)

Why ask a person to answer a problem item, when you a priori know they won’t be able to solve it? It is a waste of time and resources, and you won’t gain any new information; this is both inefficient and ... [more ▼]

Why ask a person to answer a problem item, when you a priori know they won’t be able to solve it? It is a waste of time and resources, and you won’t gain any new information; this is both inefficient and ineffective. In contrast, computerized adaptive testing (CAT) is based on the principle that more information can be gained when one tailors the test towards the level of the person being tested. Computational and statistical techniques from item response theory (IRT) and decision theory are combined to implement a test that can behave interactively during the test process and adapts towards the level of the person being tested.The implementation of such a CAT relies on an iterative sequential algorithm that searches the pool of available items (a so-called item bank) for the optimal item to administer based on the current estimate of the person’s level (and optional external constraints). The subsequent response on this item provides new information to update the person’s proficiency estimate. This selection-responding-updating process continues until specified stop criteria have been reached. The consequence of such an adaptive test administration is that you get an individualized tailored test that is more efficient and more effective. Because you have less of a mismatch between the level of the test and the level of the test taker, there is a lesser burden for the latter and a higher precision for the former, and this with fewer items than a traditional fixed item-set test format. Furthermore, because it is computerized and sequential, test performance can be continuously monitored and reported directly after test completion. Item response models come into play to ensure comparable scores of these individual tailored tests by putting them on the same measurement scale and to precalibrate,the psychometric parameters of the items that are part of the item bank on which the sequential iterative algorithm operates. The workshop intends to tackle issues encountered during the setup of a computerized adaptive test, starting from the design towards the actual delivery of a CAT. [less ▲]

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Peer Reviewed
See detailComputerized adaptive testing
Magis, David ULg; Mahalingam, Vaishali

in Da Silva, Marjorie Cristina Rocha; Bartholomeu, Daniel; Vendramini, Claudette Maria Medeiros (Eds.) et al Applicações de Métodos Estatísticos Avançadaos à Avaliação Psicológica e Educacional (2015)

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See detailComputerized adaptive testing with R: Recent updates of the package catR
Magis, David ULg; Barrada, Juan Ramon

in Journal of Statistical Software (in press)

The purpose of this paper is to list the recent updates of the R package catR. This package allows for generating response patterns under a computerized adaptive testing (CAT) framework with underlying ... [more ▼]

The purpose of this paper is to list the recent updates of the R package catR. This package allows for generating response patterns under a computerized adaptive testing (CAT) framework with underlying item response theory (IRT) models. Among the most important updates, well-known polytomous IRT models are now supported by catR; several item selection rules have been added; and it is now possible to perform post-hoc simulations. Some functions were also rewritten or withdrawn to improve the usefulness and performances of the package. [less ▲]

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See detailComputerized assessment of cognition in schizophrenia: promises and pitfalls of CANTAB.
Levaux, Marie-Noëlle ULg; Potvin, Stephane; Sepehry, Amir Ali et al

in European Psychiatry (2007), 22(2), 104-15

OBJECTIVE: Over the last decade, the Cambridge Neuropsychological Test Automated Battery (CANTAB), which comprises visuo-spatial tasks, has been utilized in cognitive studies of schizophrenia. A clear ... [more ▼]

OBJECTIVE: Over the last decade, the Cambridge Neuropsychological Test Automated Battery (CANTAB), which comprises visuo-spatial tasks, has been utilized in cognitive studies of schizophrenia. A clear approach concerning the usage of CANTAB for the appraisal of neurocognitive dysfunction in schizophrenia is currently lacking. METHOD: In this paper, we have first reviewed the overall applications of CANTAB and then evaluated methodological strengths and weaknesses of CANTAB as a neurocognitive battery for schizophrenia. We carried out a systematic search and assessment of studies where CANTAB was utilized to measure cognitive function in schizophrenia. We have also attempted to quantify the available data and perform a meta-analysis, but this approach turned out to be still premature. RESULTS: CANTAB has enabled researchers to highlight significant deficits affecting broad cognitive domains in schizophrenia, such as working memory, decision-making, attention, executive functions and visual memory. So far, the most consistent deficit observed with CANTAB testing has been attentional set-shifting, suggestive of fronto-striatal dysfunctions. In addition, preliminary evidence points towards the potential use of CANTAB to identify cognitive predictors of psychosocial functioning, to describe the relationships between symptoms and cognition, and to measure the impact of pharmacological agents on cognitive functioning. CONCLUSION: CANTAB has been used successfully to highlight the range of visuo-spatial cognitive deficits in schizophrenia, producing similar results to those obtained with some traditional neuropsychological tests. Further studies validating the use of CANTAB following the standard set by Measurement And Treatment Research to Improve Cognition in Schizophrenia (MATRICS) are warranted. [less ▲]

Detailed reference viewed: 74 (2 ULg)
See detailA computerized method adapted for pulmonary function testing in unsedated horses
Lekeux, Pierre ULg

in Deegen, E.; Beadle, R. E. (Eds.) Lung Function and Respiratory Diseases in the Horse (1985)

Detailed reference viewed: 8 (1 ULg)
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See detailA computerized open learning environment to study intrapersonal variations in learning styles : DELIN
Leclercq, Dieudonné ULg; Pierret, D.

in Estes, N. (Ed.) Proceedings of the 6th International Conference on Technology and Education (ICTE), Orlando, Florida, March 21-23, 1989 (1989, March)

Several studies have been devoted to interpersonal differences in so-called "cognitive styles" (Kagan & Kogan), 1970; WItking & Goodenough, 1977; Pask, 1976, etc.). Pask himself has emphasised the notion ... [more ▼]

Several studies have been devoted to interpersonal differences in so-called "cognitive styles" (Kagan & Kogan), 1970; WItking & Goodenough, 1977; Pask, 1976, etc.). Pask himself has emphasised the notion of versatility, i.e. the individual's capacity to switch from a strategy to an other, according to changes in conditions, constrains, etc.In order to respect both the interpersonal and intrapersonal variations in learning strategies, we have developed a software of the hypermedia type called DELIN (from the French DELINEARISE, that means non linear. [less ▲]

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Peer Reviewed
See detailComputerized tailored testing: Structured and calibred item banks for summative and formative evaluation
Leclercq, Dieudonné ULg

in European Journal of Education (1980), 15(3), 251-260

Detailed reference viewed: 16 (4 ULg)
Peer Reviewed
See detailComputerized three dimensional visualization of silver stained nucleolar organizer regions studied by high voltage electron microscopy
Ploton, Dominique; Beorchia, A; Ménager, Monique et al

in Biology of the Cell (1990), 69

Detailed reference viewed: 4 (0 ULg)
Peer Reviewed
See detailComputerized video multitracking of several small translucent fishes (glass eels) at night with fluorescent elastomer tags
Delcourt, Johann ULg; Bolliet, Valérie; Ylieff, Marc ULg et al

Poster (2010, July)

European eels (Anguilla Anguilla), an endangered species with high economic value, exhibit very unusual features in their multistage catadromous life cycle at different life stages. The reproduction of ... [more ▼]

European eels (Anguilla Anguilla), an endangered species with high economic value, exhibit very unusual features in their multistage catadromous life cycle at different life stages. The reproduction of eel takes place in the Sargasso Sea. Leptocephalus larvae use ocean currents (mainly the Gulf Stream) to migrate to European coastal areas, and then metamorphose into glass eels probably as they reach the continental shelf. Glass eel then, enter estuaries to join the fresh waters network. Knowledge about glass eel biology and migration has mainly increased in the eighties, and it is now well established that the activity during the estuary migration depends mainly on tidal cycle, even if lunar and circadian rhythms and/or direct influence of light and tidal coefficient may interact. Different migratory tactics are suspected on the basis of recent laboratory experiments (Bolliet & Labonne, 2008; Bureau du Colombier et al., 2009), notably the existence of individuals swimming only with the current, others swimming with and against the current, and others presenting a weak degree of activity. The propensity to migrate and glass eels energy content would be linked and may result in different migratory behaviours possibly leading to estuarine settlement (Bureau du Colombier et al., 2007; 2009). Unfortunately, few are known about the glass eel swimming behaviours in estuaries, a crucial point to better understand their estuarine migration: such knowledge would help to characterize the migratory tactics and to better understand the link with energy status. The videotracking system [EthoVision Color-Pro 3.1 (Noldus Information Technology)] which allows to measure automatically the movements of individuals represents an interesting tool to progress in this questioning. Nowadays, video tracking to measure fish behaviours is relatively frequent, but is rather rare in the ecological studies. Moreover, tracking a transparent animal, under water current conditions is a real challenge, particularly at night. To detect the individuals, several eels are marked by a fluorescent VIE tag (Visible Implant Elastomer, Northwest Marine Technology Inc.). VIE do no affect growth, survival and behaviour of tagged glass eels. Initially developed to improve the identification of individual tags in mark-recapture studies of aquatic animals, VIE tags are used here for a new extreme application in ethometry: the study of behaviours of transparent animals in weaker luminosity and in the dark by automatic tracking technology. The individual identification is based on the fluorescent color (red, blue, yellow and green) emitted by the VIE tag injected in the muscle mass on the basis of dorsal fin. The detection of the four marks is excellent. It allows measuring the activity (notably path and speed) of each tagged individuals as a function of tidal and nycthemeral rhythms in the same chronotron (circular aquarium simulating the estuarine conditions) and spatial use at a wide time scale from second to week. Another advantage is the possibility of tracked animals to go out the analysed arena without error of identification when it appears again in the analysed zone. This multitracking method by fluorescent VIE tags could be applied to a large number of species (crustaceans, fish, holothurians, amphibians, …). References: Bolliet & Labonne, 2008 Journal of Experimental Marine Biology and Ecology 362, 125-130; Bureau du Colombier et al., 2007 Physiology & Behavior 92, 684-690 ; Bureau du Colombier et al., 2009 Journal of Fish Biology 74, 2002-2013. Acknowledgements: This work was financially supported by FNRS-FRS (National fund of Research, Belgium) (project n°2.4617.08, n°2.4569.06, n°2.4569.10F), by Hubert Curien Tournesol project and by an EGIDE Grant. We thank J-C. Aymes for its help in testing the video tracking software and system. We are also highly grateful to Jacques Rives for its help in settling and monitoring the experiments. [less ▲]

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See detailComputers As Genomic Time Machines for Meeting our Ancestors
Baurain, Denis ULg

Scientific conference (2013, April 18)

Detailed reference viewed: 31 (4 ULg)
Peer Reviewed
See detailComputers in Veterinary Medicine - The situation in Belgium
Leroy, Pascal ULg

in UEVP's Electronic Data Processing, München, 1983 (1983)

Detailed reference viewed: 6 (0 ULg)
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See detailComputing accurately the induced land subsidence affecting the main sinking cities located at major river mouths
Dassargues, Alain ULg

in Advances in Hydro-Science and Engineering - Volume 1 -ICHE Washington (1993)

Detailed reference viewed: 18 (5 ULg)
See detailCOMPUTING ANTICIPATORY SYSTEMS, CASYS'09 - Ninth International Conference, Liège, Belgium, 3-8 August 2009
Dubois, Daniel ULg

Book published by American Institute of Physics (2010)

Detailed reference viewed: 45 (2 ULg)
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See detailComputing bounds for kernel-based policy evaluation in reinforcement learning
Fonteneau, Raphaël ULg; Murphy, Susan A.; Wehenkel, Louis ULg et al

Report (2010)

This technical report proposes an approach for computing bounds on the finite-time return of a policy using kernel-based approximators from a sample of trajectories in a continuous state space and ... [more ▼]

This technical report proposes an approach for computing bounds on the finite-time return of a policy using kernel-based approximators from a sample of trajectories in a continuous state space and deterministic framework. [less ▲]

Detailed reference viewed: 18 (3 ULg)
Peer Reviewed
See detailComputing bounds on the geometrical quality of 2D curvilinear finite elements
Johnen, Amaury ULg; Remacle, J.-F.; Toulorge, T. et al

Conference (2013, April 25)

The development of high-order computational methods for solving partial differen- tial equations on unstructured grids has been underway for many years. Such meth- ods critically depend on the ... [more ▼]

The development of high-order computational methods for solving partial differen- tial equations on unstructured grids has been underway for many years. Such meth- ods critically depend on the availability of high-quality curvilinear meshes, as one badly-shaped element can degrade the solution in the whole domain (J. Shewchuk, “What Is a Good Linear Finite Element? Interpolation, Conditioning, Anisotropy, and Quality Measures”, Preprint, 2002). The usual way of generating curved meshes is to first generate a straight sided mesh and to curve mesh entities that are classified on the boundaries of the domain. The latter operation introduces a “shape-distortion” that should be controlled if we suppose that the straight sided mesh is composed of well-shaped elements. Quality measures allow to quantify to which point an element is well-shaped. They also provide tools to improve the quality of meshes through optimization opera- tions. Many quality measures has been proposed for quadratic triangular finite element. Recently, X. Roca et al. (“Defining Quality Measures for High-Order Planar Triangles and Curved Mesh Generation”, Proceedings of the 20th Interna- tional Meshing Roundtable, 2011) proposed a technique that allows extending any Jacobian based quality measure for linear elements to high-order iso-parametric planar triangles of any interpolation degree. In this work we propose an efficient method to provide accurate bounds on the mag- nitude of the shape distortion of any triangular and quadrangular curved element. The shape distortion is measured with respect to an ideal element, which can e.g. be an equilateral triangle or the element from the original straight-sided mesh. The key feature of the method is that we can adaptively expand functions based on the Jacobian matrix and its determinant in terms of Be ́zier functions. Be ́zier functions have both properties of boundedness and positivity, which allow sharp computation of minimum or maximum of the interpolated functions. [less ▲]

Detailed reference viewed: 81 (20 ULg)