Conceptions d'élèves sur la notion de probabilité conditionnelle révélées par une méthode d'analyse des donn ées: Implication - similarité - corrélation

Résumé L'introduction des notions de probabilité, a fortiori celle de probabilité conditionnelle, pose un problème didactique épineux en raison de préconceptions des élèves (Fischbein et al., 1991), nées des références concr ètes indispensables à cette introduction. Ces préconceptions peuvent se renforcer en conceptions qui se posent en obstacles épistémologiques et obstacles d'origine didactique. À l'aide d'une nouvelle méthode d'analyse de donn ées — l'implication statistique — et d'une méthodologie d'emploi post-corré1ative, nous mettons en évidence ces conceptions à partir des travaux d'élèves et en explicitant des procédures de résolution de problèmes, rév é1atrices de ces conceptions.

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Students' conceptions on conditional probability revealed by a data analysis method: Implication - similarity - correlation

The introduction of notions of probability, above all conditional probability, poses a thorny problem in didactics due to student's preconceptions (Fischbein et al., 1991), stemming from the concrete references indispensable for this introduction. These preconceptions may be reinforced by conceptions which become epistemological and especially didactical obstacles. Using a new method of data analysis — statistical implication - and a method of post-correlative treatment, we reveal these conceptions using student's work, and make explicite the procedures of problem solving used, that are a reflexion of these conceptions.

     

"Thinking the Practice": Academic adult educators' reflections on mediating a summer institute as a multicultural learning journey for graduate students

In this paper we research our roles as academic adult educators who worked with 40 graduate students during a 10 day summer institute, which we developed using the theme "Culture and Diversity in Education for Adults". We discuss how we framed the development and delivery of this summer institute in the context of a transgressive and transformative learning journey that heeds Paulo Freire's (1998) call to "think the practice" by reading and comprehending the word and the world critically. From this perspective, we examine our positionalities that situate us as present, sometimes strong, yet sometimes vulnerable educators who use insurgent theories and positional pedagogies to shape alternative learning experiences. We also examine how these positionalities impact our conceptions of pedagogy and multiculturalism, and we explore how they helped to shape the inclusive teaching-learning interactions that we designed to query being, acting, becoming, belonging, and surviving in education and the larger Canadian and global cultures. In this regard we investigate how our learning journey emerged as one deeply textured by engagements with issues of educator and learner positionalities as well as matters of context, disposition, relationship, and affiliation. We explore how our learning journey with institute participants took us into the uneasy intersections of the personal, professional, and political where pedagogical practices and associated challenges, risks, possibilities, and liabilities emerge.     

Gender,prior knowledge,interest, and experience in electricity and conceptual change text manipulations in learning about direct current

The present study investigated relationships between gender, interest and experience in electricity, and conceptual change text manipulations on learning fundamental direct current concepts. Conceptual change text has been shown to lead to better conceptual understanding of electrical concepts than traditional didactic text, but previous research suggested that the effect interacted with the gender of the participants. We hypothesized that interest moderated this interaction. In this study, men and women who had higher or lower interest in electricity and greater or lessor experience with electricity read conceptual change or traditional text. When interest level, experience, and prior knowledge were not included in the analysis, both gender and text type produced significant main effects. When interest level, experience, and prior knowledge were included in the analysis, conceptual change text led to better understanding of electricity concepts than did the traditional text, and the effect of gender was eliminated. This finding supports the hypothesis that prior interest level, experience, and knowledge mediate apparent gender differences in learning about electricity. It suggests that conceptual change text manipulations are likely to be effective for both men and women. © 1997 John Wiley & Sons, Inc. J Res Sci Teach 34: 107–123, 1997.     

‘Foreign ownerships’ in the Premier League: examining local Liverpool fans’ perceptions of Fenway Sports Group

The ‘foreign ownerships’ apparent in the English Premier League have received little academic attention, despite being a controversial issue for football fans and commentators. This study examines local Liverpool Football Clubs fans’ perceptions of the clubs’ American ownership and to what extent criticism aimed at the owners are framed in terms of nationality. Hence, data from the ‘Red and White Kop’s’ online message board (found at www.redandwhitekop.com) were collected. This is an interactive message board used primarily by Liverpool fans. The purposively sampled data, consisting of 3,322 fan comments was analysed with a frame analyse technique advanced by Erving Goffman. The study’s main argument is that Liverpool fans have become normalized to the global features of football, thus the nationality of the clubs’ owner seems unproblematic, when they assess the club’s ownership; an ownership a significant number of fans have positive perceptions about.     

Attentional Mechanisms in Sports Via Brain-Electrical Event-Related Potentials

In this study, we examined attention processes in complex, sport-specific decision-making tasks without interdependencies from anticipation. Psychophysiological and performance data recorded from advanced and intermediate level basketball referees were compared. Event-related potentials obtained while judging game situations in foul recognition and a control task provided insight into focus of attention, selective attention, and processing strategy (top-down vs. bottom-up). Results showed task-specific effects for advanced referees in components influenced by attentional focus and selective attention. Experts also seemed to profit from superior top-down strategy and were able to evaluate the stimuli more rapidly. These findings are discussed in connection with current models in neurosciences and theories of referee research.     

Effect of biological maturation on maximal oxygen uptake and ventilatory thresholds in soccer players: An allometric approach

Abstract

In this study, we investigated the effect of biological maturation on maximal oxygen uptake ([Vdot]O_2max) and ventilatory thresholds (VT₁ and VT₂) in 110 young soccer players separated into pubescent and post-pubescent groups.. Maximal oxygen uptake and [Vdot]O₂ corresponding to VT₁ and VT₂ were expressed as absolute values, ratio standards, theoretical exponents, and experimentally observed exponents. Absolute [Vdot]O₂ (ml · min^?1) was different between groups for VT₁, VT₂, and [Vdot]O_2max. Ratio standards (ml · kg^?1 · min^?1) were not significantly different between groups for VT₁, VT₂, and [Vdot]O_2max. Theoretical exponents (ml · kg^?0.67 · min^?1 and ml · kg^?0.75 · min^?1) were not properly adjusted for the body mass effects on VT₁, VT₂, and [Vdot]O_2max. When the data were correctly adjusted using experimentally observed exponents, VT₁ (ml · kg^?0.94 · min^?1) and VT₂ (ml · kg^?0.95 · min^?1) were not different between groups. The experimentally observed exponent for [Vdot]O_2max (ml · kg^?0.90 · min^?1) was different between groups (P = 0.048); however, this difference could not be attributed to biological maturation. In conclusion, biological maturation had no effect on VT₁, VT₂ or [Vdot]O_2max when the effect of body mass was adjusted by experimentally observed exponents. Thus, when evaluating the physiological performance of young soccer players, allometric scaling needs to be taken into account instead of using theoretical approaches.     

The geometric curvature of the spine during the sirshasana,the yoga’s headstand

This study analysed the behaviour of the geometric curvature of the spine during sirshasana. The position of dorsal retroreflective markers was computed via stereophotogrammetric analysis in six males and five females (29.4 ± 8.8 years, 63.0 ± 11.4 kg, 1.66 ± 0.08 m [average ± standard deviation]). The spinal points were projected onto the sagittal and frontal planes of the trunk, a polynomial was fitted to the data and the two-dimensional geometric curvature was quantified. The inferior lumbar lordosis decreased compared to the orthostatic position and gait, which may favour the posterior protrusion of the lumbar spinal nucleus pulposus in people with posterior herniation. The lateral deviation at the middle of the thoracic spine increases during sirshasana, which may reflect increased difficulties for postural control and spinal loads. It could be useful for promoting positive spinal structural and functional chronic adaptations for healthy participants, if the yoga programme is carefully planned and the spinal alignment is carefully monitored during a headstand. However, it may aggravate some spinal diseases, especially scoliosis.     

一个美国人眼中的中原文化

美国人普遍以老大自居,他们对亚洲、对中国了解很少.但也有一些美国人发现中国的文化,中国的历史其实是非常迷人的,偶或有对中华文化起源感兴趣的,河南便成了他们心目中的"麦加".