14 research outputs found

    A systematic review of the use of log-based process data in computer-based assessments

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    Examining change in students’ self-regulated learning patterns after a formative assessment using process mining techniques

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    We share the analyses code for data pre-processing and conducting pMine

    A Comparison of Undersampling, Oversampling, and SMOTE Methods for Dealing with Imbalanced Classification in Educational Data Mining

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    Educational data mining is capable of producing useful data-driven applications (e.g., early warning systems in schools or the prediction of students’ academic achievement) based on predictive models. However, the class imbalance problem in educational datasets could hamper the accuracy of predictive models as many of these models are designed on the assumption that the predicted class is balanced. Although previous studies proposed several methods to deal with the imbalanced class problem, most of them focused on the technical details of how to improve each technique, while only a few focused on the application aspect, especially for the application of data with different imbalance ratios. In this study, we compared several sampling techniques to handle the different ratios of the class imbalance problem (i.e., moderately or extremely imbalanced classifications) using the High School Longitudinal Study of 2009 dataset. For our comparison, we used random oversampling (ROS), random undersampling (RUS), and the combination of the synthetic minority oversampling technique for nominal and continuous (SMOTE-NC) and RUS as a hybrid resampling technique. We used the Random Forest as our classification algorithm to evaluate the results of each sampling technique. Our results show that random oversampling for moderately imbalanced data and hybrid resampling for extremely imbalanced data seem to work best. The implications for educational data mining applications and suggestions for future research are discussed

    The impact of power on humanity: self-dehumanization in powerlessness.

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    Power gives people the ability to control themselves and their environment, and this control is considered a fundamental human need. We investigated whether experiencing powerlessness induces the experience of self-dehumanization using three methods: priming, role-playing, and cueing. People in a position of low power viewed themselves (Experiments 1-3) as less human relative to people in a position of high power; furthermore, people with low power believed that they were viewed as less human by others as well (Experiments 2-3). In all of the experiments, human nature traits were most negatively affected by powerlessness in self-perception judgments, and uniquely human traits were most negatively affected by powerlessness in meta-perception judgments. Furthermore, the powerless believed they were viewed as less human not only by the powerful people but also the outside observers of the power dynamic. Self-dehumanization also appears to be a consequence of powerlessness rather than an incidental result of a change in mood or a negative self-view. Our findings are an important extension of previous work on the adverse effects of powerlessness and dehumanization

    Mean meta-perception ratings of human traits across conditions in Experiment 3.

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    <p>Mean meta-perception ratings of human traits across conditions in Experiment 3.</p

    Mean self-perception ratings of human traits across conditions in Experiment 1.

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    <p>Mean self-perception ratings of human traits across conditions in Experiment 1.</p

    Genetic Diversity and Demographic History of Wild and Cultivated/Naturalised Plant Populations: Evidence from Dalmatian Sage (Salvia officinalis L., Lamiaceae)

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    Dalmatian sage (Salvia officinalis L., Lamiaceae) is a well-known aromatic and medicinal Mediterranean plant that is native in coastal regions of the western Balkan and southern Apennine Peninsulas and is commonly cultivated worldwide. It is widely used in the food, pharmaceutical and cosmetic industries. Knowledge of its genetic diversity and spatiotemporal patterns is important for plant breeding programmes and conservation. We used eight microsatellite markers to investigate evolutionary history of indigenous populations as well as genetic diversity and structure within and among indigenous and cultivated/naturalised populations distributed across the Balkan Peninsula. The results showed a clear separation between the indigenous and cultivated/naturalised groups, with the cultivated material originating from one restricted geographical area. Most of the genetic diversity in both groups was attributable to differences among individuals within populations, although spatial genetic analysis of indigenous populations indicated the existence of isolation by distance. Geographical structuring of indigenous populations was found using clustering analysis, with three sub-clusters of indigenous populations. The highest level of gene diversity and the greatest number of private alleles were found in the central part of the eastern Adriatic coast, while decreases in gene diversity and number of private alleles were evident towards the northwestern Adriatic coast and southern and eastern regions of the Balkan Peninsula. The results of Ecological Niche Modelling during Last Glacial Maximum and Approximate Bayesian Computation suggested two plausible evolutionary trajectories: 1) the species survived in the glacial refugium in southern Adriatic coastal region with subsequent colonization events towards northern, eastern and southern Balkan Peninsula; 2) species survived in several refugia exhibiting concurrent divergence into three genetic groups. The insight into genetic diversity and structure also provide the baseline data for conservation of S. officinalis genetic resources valuable for future breeding programmes

    Colonización en las tierras áridas de Norteamérica: El viaje de Agarito (Berberis trifoliolata) revelado por datos moleculares multilocus y restos fósiles de Packrat Midden

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    Here we conduct research to understand the evolutionary history of a shrubby species known as Agarito (Berberis trifoliolata), an endemic species to the Chihuahuan Desert. We identify genetic signatures based on plastid DNA and AFLP markers and perform niche modelling and spatial connectivity analyses as well as niche modelling based on records in packrats to elucidate whether orogenic events such as mountain range uplift in the Miocene or the contraction/expansion dynamics of vegetation in response to climate oscillations in the Pliocene/Pleistocene had an effect on evolutionary processes in Agarito. Our results of current niche modelling and palaeomodelling showed that the area currently occupied by Berberis trifoliolata is substantially larger than it was during the Last Interglacial period and the Last Glacial Maximum. Agarito was probably confined to small areas in the Northeastern and gradually expanded its distribution just after the Last Glacial Maximum when the weather in the Chihuahuan Desert and adjacent regions became progressively warmer and drier. The most contracted range was predicted for the Interglacial period. Populations remained in stable areas during the Last Glacial Maximum and expanded at the beginning of the Holocene. Most genetic variation occured in populations from the Sierra Madre Oriental. Two groups of haplotypes were identified: the Mexican Plateau populations and certain Northeastern populations. Haplogroups were spatially connected during the Last Glacial Maximum and separated during interglacial periods. The most important prediction of packrat middens palaeomodelling lies in the Mexican Plateau, a finding congruent with current and past niche modelling predictions for agarito and genetic results. Our results corroborate that these climate changes in the Pliocene/Pleistocene affected the evolutionary history of agarito. The journey of agarito in the Chihuahuan Desert has been dynamic, expanding and contracting its distribution range and currently occupying the largest area in its history.Aquí realizamos una investigación para comprender la historia evolutiva de una especie arbustiva conocida como Agarito (Berberis trifoliolata), una especie endémica del desierto de Chihuahua. Identificamos firmas genéticas basadas en marcadores de ADN plastidial y AFLP y realizamos análisis de modelado de nicho y de conectividad espacial, así como de modelado de nicho basado en registros en packrats para dilucidar si los eventos orogénicos como el levantamiento de la cordillera en el Mioceno o la dinámica de contracción/expansión de la vegetación en respuesta a las oscilaciones climáticas en el Plioceno/Pleistoceno tuvieron un efecto en los procesos evolutivos de Agarito. Nuestros resultados de la modelización del nicho actual y de la paleomodelización mostraron que el área ocupada actualmente por Berberis trifoliolata es sustancialmente mayor de lo que era durante el último período interglacial y el último máximo glacial. El agarito estaba probablemente confinado en pequeñas zonas del noreste y amplió gradualmente su distribución justo después del Último Máximo Glacial, cuando el clima en el desierto de Chihuahua y las regiones adyacentes se volvió progresivamente más cálido y seco. El área de distribución más contraída se predijo para el periodo interglaciar. Las poblaciones permanecieron en zonas estables durante el Último Máximo Glacial y se expandieron a principios del Holoceno. La mayor variación genética se produjo en las poblaciones de la Sierra Madre Oriental. Se identificaron dos grupos de haplotipos: las poblaciones de la Meseta Mexicana y ciertas poblaciones del Noreste. Los haplogrupos estuvieron conectados espacialmente durante el Último Máximo Glacial y se separaron durante los periodos interglaciares. La predicción más importante de la paleomodelación de los muladares de las ratas de carga se sitúa en la Meseta Mexicana, un hallazgo congruente con las predicciones actuales y pasadas de la modelización del nicho del agarito y los resultados genéticos. Nuestros resultados corroboran que estos cambios climáticos en el Plioceno/Pleistoceno afectaron a la historia evolutiva del agarito. El recorrido del agarito en el Desierto Chihuahuense ha sido dinámico, expandiendo y contrayendo su rango de distribución y ocupando actualmente la mayor área de su historia.Fil: Angulo, Diego F. Universidad Autónoma de Yucatán; México.Fil: Amarilla, Leonardo D. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales; Argentina.Fil: Amarilla, Leonardo D. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto Multidisciplinario de Biología Vegetal; Argentina.Fil: Anton, Ana M. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales; Argentina.Fil: Anton, Ana M. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto Multidisciplinario de Biología Vegetal; Argentina.Fil: Sosa, Victoria. Instituto de Ecología. Departamento de Biología Evolutiva; México
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