5,210 research outputs found
The role of international student interactions in English as a lingua franca in L2 acquisition, L2 motivational development and intercultural learning during study abroad
Crossing borders features prominently as a theme in study abroad, not only in terms of students’ physical border crossings but also in their intercultural interactions with second language (L2) speakers whose background (linguistic and otherwise) they may perceive as markedly different from their own. Researchers have had a long-standing interest in study abroad participants’ interactions with other L2 speakers abroad for their perceived potential to enhance L2 development, L2 motivation and intercultural learning processes. The focus of existing studies in this area has been on the interactions of study abroad participants with host national students, while their interactions with other international students who are also L2 users abroad have received far less attention, despite the ever-growing international student populations at European universities. This study examined students’ views regarding the role that lingua franca (LF) interactions with other international students played in their L2 acquisition, their L2 motivational development and their intercultural learning during study abroad. The data were derived from an empirical study that involved 81 German ERASMUS students who were studying in the UK for up to one academic year. The students’ views were elicited at the end of their stay with open-ended questionnaire items, and their verbal responses were analyzed using thematic content analysis. The analysis of the students’ reflections revealed a number of functions in each of the three areas, highlighting the potential of international student interactions as a viable source of L2 acquisition, L2 self-motivation, and intercultural learning during study abroad
College Student Perceptions of Varying Disability Types: Does Contact Experience Matter?
Studies exploring prejudices between groups have suggested that contact is related to attitudes. This relationship has been studied in the context of attitudes toward people with disabilities and has yielded inconsistent results. Other variables, such as gender, type of relationship, and the type of disability, have been studied in conjunction with and distinct from the contact variable. The present study, conducted among college students, investigated if the contact experience or the exposure to a specific type of disability in a vignette individually were associated with the attitude variable of social distance, as well as if there was an interaction between the two independent variables. Contact experience did not significantly predict scores on the social distance measure; however, type of disability was a significant predictor of undergraduate students’ social distance attitudes. Specifically, physical disability predicted significantly lower scores of social distance than intellectual disability, Attention-Deficit Hyperactivity disorder, and Autism Spectrum Disorder. The results of this research were consistent with prior studies measuring similar variables, prompting a need for further research on the role of contact experience and disability type in forming prejudices toward people with disabilities. As type of disability seems to play a significant role in attitudes toward people with disabilities, greater efforts should be directed towards educating students and faculty on non-physical disability types
Book Review
Review of: ANN RAPPAPORT & MARGARET FRESHER FLAHERTY, CORPORATE RESPONSES TO ENVIRONMENTAL CHALLENGES: INITIATIVES BY MULTINATIONAL MANAGEMENT. (Quorum Books 1992) [186 pp.] Acknowledgements, bibliography, figures, foreword, index, notes, tables. LC: 91-44706; ISBN: 0-89930-715-9 [Cloth $45.00.
Book Review
Review of the following: BIOMEDICAL POLITICS. (Kathi E. Hanna, ed., National Academy Press 1991) [352 pp.] Preface and acknowledgements, Carl W. Gottschalk, Chair, Institute of Medicine Committee to Study Biomedical Decision Making. Appendices, biographical notes on authors and commentators, index, notes, references. LC 91- 18394, ISBN 0-309-04486-3. [Cloth 36.00. 2101 Constitution Ave., NW, Washington DC 20418.
Resolute Choice in interaction: a qualitative experiment.
The purpose of this paper is that of extending the model of Resolute Choice (McClennen 1990) to a situation of interaction and comparing its performance with the Sophisticated-subgame perfect equilibrium model in an experiment. A non-cooperative game in which two players with different preference orderings over outcomes move sequentially is adopted as a framework to compare the two models. I consider those combinations of the players' preference structures which generate the different plans and find those game situations where either one or two outcomes Pareto-dominant over Sophisticated Choice exist. Two definitions of Resolute Choice are therefore tested, which allow to discriminate choice between two different Pareto dominant outcomes. In the experiment three games with the same structure but different payoffs are played. The design allows preliminary group discussion among the players about the decisions to be taken, which is taped and transcribed. The results show support for Resolute Choice as Pareto dominance, while the ability of Resolute Choice as Nash bargaining to explain behaviour is quite limited. The subjects' motivations are very useful in interpreting the results. They show that choice for a Pareto dominant outcome is mainly driven by the idea of Pareto optimality itself. Motivations differ slightly according to which strategy is chosen to reach one of the Pareto dominant outcomes. A result to be noted is the relevance of the different payoffs of the games in motivating choice. The method used in the experiment to elicit the subjects' responses is the strategy method. A direct consequence is that the results are all in terms of strategies chosen by subjects. In view of this, an alternative way to look at the experiment results has been tried, which consists in a simulation of the outcomes of the games that would have resulted from direct interaction among the players. The results have then been compared to the ones from the experiment.dynamic decision making, myopia, sophistication, resoluteness, non-cooperative game
Limit results for discretely observed stochastic volatility models with leverage e¤ect
In this note we generalize the limit results in [Genon-Catalot, Jeantheau, Laredo, 2000, Bernoulli ] for simple stochastic volatility models to the case where a non zero correlation is allowed between the Brownian mo- tion driving the main di¤usion process and the Brownian motion driving the dymaics of the instantaneous variance. We also extend the results to the case where the main di¤usion admits a non zero drift which is linear in the variance process. The main motivation for such an extension is the application of these limit results in order to perform statistical infer- ence in some of the stochastic volatility models introduced in the ?nancial mathematics literature. In this framework it is of relevance the so called "leverage e¤ect" between the stock log-price and its volatility, which is indeed explained by a negative correlation between the Brownian motions driving the log-price process and its instantaneous variance. Moreover a linear term in the variance appears in the drift of the log-price diffusion.
Path properties of simulation schemes for the Heston stochastic volatility model.
The aim of this study is to evaluate some simulation schemes recently suggested for the Heston model by examining their ability in reproducing, on the simulated paths, the autocovariance function of the generated model, when discretely observed. This is done by applying the outcomes of previous research where, based on discrete equi-spaced observations of the log-price, we determined an approximate confidence band for the theoretical autocovariance function of the mean variance process.
The Performance of SETAR models by Regime: A Conditional Evaluation of Interval and Density Forecasts
The aim of this paper is to analyse the out-of-sample performance of SETAR models using daily data for the Euro effective exchange rate. The evaluation is conducted on point, interval and density forecasts. The benchmark used for the comparison is a linear AR model for point forecast evaluation and a GARCH model for interval and density forecasts. In each case the models are evaluated unconditionally, over the whole forecast period, and conditionally, on the regimes of the SETAR models. The results show that, in general, the performance of the SETAR models improves significantly for the forecasts governed by the regime(s) with fewer observations. However, overall the GARCH model is better able to capture the distributional features of the series and to predict higher ordered moments.SETAR models, point forecasts, interval forecasts, density forecasts, Euro effective exchange rate
THE PERFORMANCE OF SETAR MODELS : A REGIME CONDITIONAL EVALUATION OF POINT, INTERVAL AND DENSITY FORECASTS
The aim of this paper is to analyse the out-of-sample performance of SETAR models relative to a linear AR and a GARCH model using daily data for the Euro effective exchange rate. The evaluation is conducted on point, interval and density forecasts, unconditionally, over the whole forecast period, and conditional on specific regimes. The results show that overall the GARCH model is better able to capture the distributional features of the series and to predict higher-order moments than the SETAR models. However, from the results there is also a clear indication that the performance of the SETAR models improves significantly conditional on being on specific regimes.SETAR models ; forecasting accuracy ; point forecasts ; MSFEs ; interval forecasts ; density forecasts ; Euro effective exchange rate
Extropy: Complementary Dual of Entropy
This article provides a completion to theories of information based on
entropy, resolving a longstanding question in its axiomatization as proposed by
Shannon and pursued by Jaynes. We show that Shannon's entropy function has a
complementary dual function which we call "extropy." The entropy and the
extropy of a binary distribution are identical. However, the measure bifurcates
into a pair of distinct measures for any quantity that is not merely an event
indicator. As with entropy, the maximum extropy distribution is also the
uniform distribution, and both measures are invariant with respect to
permutations of their mass functions. However, they behave quite differently in
their assessments of the refinement of a distribution, the axiom which
concerned Shannon and Jaynes. Their duality is specified via the relationship
among the entropies and extropies of course and fine partitions. We also
analyze the extropy function for densities, showing that relative extropy
constitutes a dual to the Kullback-Leibler divergence, widely recognized as the
continuous entropy measure. These results are unified within the general
structure of Bregman divergences. In this context they identify half the
metric as the extropic dual to the entropic directed distance. We describe a
statistical application to the scoring of sequential forecast distributions
which provoked the discovery.Comment: Published at http://dx.doi.org/10.1214/14-STS430 in the Statistical
Science (http://www.imstat.org/sts/) by the Institute of Mathematical
Statistics (http://www.imstat.org
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