Effects of self‐monitoring,token reinforcement and different back‐up reinforcers on the classroom behaviour of retardates

Following a baseline observation period, a class of intellectually handicapped boys were given opportunities to monitor and record their own behaviour as on‐task or off‐task. Following this self‐monitoring phase, the self‐administered check‐marks were used as tokens and exchanged for back‐up consequences, which were initially low‐value objects for consumption (possession). These were later increased in value, and finally changed to access consequences (the opportunity to play with but not possess). Self‐monitoring alone produced a significant increment in the externally assessed level of on‐task behaviour. Only when access back‐up consequences were introduced was there a further significant increment. Provision of high‐value consumption consequences was followed by a loss of accuracy in self‐monitoring, and reduction in on‐task behaviour to baseline levels. The study demonstrated the extension of a self‐control procedure to retardates, the importance of separately measuring the effect of self‐monitoring on the target behaviour, and the need for appropriate selection of back‐up consequences.     

Discriminant Validity of the Parent and Child Scales of the Parenting Stress Index

The aim of the present study was to further validate the Parental Stress Index (PSI; Abidin, 1990) which claims to measure distinct sources of stress related to the parent and the child. Two hundred and forty five mothers completed the French version of the PSI and other questionnaires including the DAS (Spanier, 1976), the CBCL (Achenbach & Edelbrock, 1981) and the BDI (Beck, et al., 1961). A subsample of 218 mothers and their preschoolers were also directly observed during a problem solving task in the laboratory. In general, regression analyses indicated that both parent and child scales contributed significantly and independently to the prediction of marital adjustment, depression, the child's problems as reported by the mother and behaviors observed in the laboratory. As expected, the parent's scale when entered first explained most of the variance for factors related to the mother, such as marital adjustment (29%) and depression (45%), and the child's scale obtained no significant results when entered last. Moreover, the child's scale contributed over and above the parent's scale in predicting the child's difficulties (12%) as reported by the mother, and accounted for all the variance when entered first (31%). Intriguingly, results showed that the child scale significantly predicted mother and child behavior in the laboratory situation, but the parent scale contributed to the explained variance only when entered first. In general, these results suggest that the two main factors of the PSI represent valid and relatively independent sources of information. Considering clinical and research applications, the PSI may be particularly useful in assessing combinations of stressors, which appear to be specifically harmful for the parent-child relationship.     

Physiological demands of top-class soccer refereeing in relation to physical capacity: effect of intense intermittent exercise training

To examine the activity profile and physiological demands of top-class soccer refereeing, we performed computerized time-motion analyses and measured the heart rate and blood lactate concentration of 27 referees during 43 competitive matches in the two top Danish leagues. To relate match performance to physical capacity and training, several physiological tests were performed before and after intermittent exercise training. Total distance covered was 10.07 - 0.13 km (mean - s x ), of which 1.67 - 0.08 km was high-intensity running. High-intensity running and backwards running decreased (P ? 0.05) in the second half. Mean heart rate was 162 - 2 beats· min -1 (85 - 1% of maximal heart rate) and the mean blood lactate concentration was 4.9 - 0.3 (range 1.7-14.0) mmol·l -1 . The amount of high-intensity running during a match was related to the Yo-Yo intermittent recovery test ( r 2 = 0.57; P ? 0.05) and the 12 min run ( r 2 = 0.21; P ? 0.05). After intermittent training ( n = 8), distance covered during high-intensity running was greater (2.06 - 0.13 vs 1.69 - 0.08 km; P ? 0.05) and mean heart rate was lower (159 - 1 vs 164 - 2 beats· min -1 ; P ? 0.05) than before training. The results of the present study demonstrate that: (1) top-class soccer referees have significant aerobic energy expenditure throughout a game and episodes of considerable anaerobic energy turnover; (2) the ability to perform high-intensity running is reduced towards the end of matches; (3) the Yo-Yo intermittent recovery test can be used to evaluate referees' match performance; and (4) intense intermittent exercise training improves referees' performance capacity during a game.     

Establishing open and critical discourses in the science classroom: Reflecting on initial difficulties

This paper presents a reflective account of a science teacher’s endeavours to use the referent of critical constructivism to transform her pedagogical practices. The context of her action research was a Year 10 Bioethics unit taught at an independent girls’ school in Perth, Western Australia. Students were provided with opportunities to engage in open and critical discourses; many did, but a few were unwilling to participate in accordance with the teacher’s intentions. We illustrate the disruptive influence of these “dissident” students and explore the reasons for their unwillingness to suspend their disbelief in a new way of knowing (and of being) that involves a radical change in the role of language in the classroom. We conclude with recommendations for epistemological pluralism and the careful use of critical discourse for re-negotiating teaching and learning roles and creating conditions for open discourse to flourish.     

Differential scanning calorimetry: Fundamental overview

This paper discusses the fundamentals of Differential Scanning Calorimetry (DSC) including functions and outputs of a Differential Scanning Calorimeter along with common uses in academia and industry.     

The good,the bad and the wiki: Evaluating student‐generated content for collaborative learning

This paper explores the potential for wiki‐type open architecture software to promote and support collaborative learning through the use of student‐created content. It delineates some of the affordances and constraints of wiki software as an open architecture that has the potential to facilitate collaborative learning through community‐focused enquiry. It seeks to promote debate in this key area of development, and highlights some recent key contributions to the developing discourse on social software in what has been termed ‘the architecture of participation’.     

Exploring the Robustness of a Unidimensional Item Response Theory Model With Empirically Multidimensional Data

Unidimensionality and local independence are two common assumptions of item response theory. The former implies that all items measure a common latent trait, while the latter implies that responses are independent, conditional on respondents’ location on the latent trait. Yet, few tests are truly unidimensional. Unmodeled dimensions may result in test items displaying dependencies, which can lead to misestimated parameters and inflated reliability estimates. In this article, we investigate the dimensionality of interim mathematics tests and evaluate the extent to which modeling minor dimensions in the data change model parameter estimates. We found evidence of minor dimensions, but parameter estimates across models were similar. Our results indicate that minor dimensions outside the primary trait have negligible consequences on parameter estimates. This finding was observed despite the ratio of multidimensional to unidimensional items being above previously recommended thresholds.     

Interpretation and application of the offside law by expert assistant referees: Perception of spatial positions in complex dynamic events on and off the field

Abstract

Baldo et al. (2002 Baldo, M. V. C., Ranvaud, R. D. and Morya, E. 2002. Flag errors in soccer games: The flash-lag effect brought to real life. Perception, 31: 1205–1210. [Crossref], [PubMed], [Web of Science ®] , [Google Scholar]) and Helsen et al. (2006 Helsen, W., Gilis, B. and Weston, M. 2006. Errors in judging “offside” in association football: Test of the optical error versus the perceptual flash-lag hypothesis. Journal of Sports Sciences, 24: 521–528. [Taylor & Francis Online], [Web of Science ®] , [Google Scholar]) considered the flash-lag effect to explain errors made by assistant referees when judging offside in association football. The main aims of the present study were as follows: (1) to determine whether the flash-lag effect emerges in offside situations on the field of play or off the field when presented as computer animations or as video footage of real-life matches; (2) to examine offside decision-making errors in two standards of assistant referee – international FIFA and Belgian national referees. The results support the flash-lag hypothesis in several ways. First, both the FIFA and Belgian assistant referees were more likely to make errors by raising their flag when they had to assess offside situations on the field of play and when presented as three-a-side computer animations. Second, more flag errors were made when the defender moved in the opposite direction to that of the attacker. Third, the strategy of raising the flag in case of doubt was not observed when an interpretation of the offside law had to be made about the involvement of play of an attacker. Future research is needed to examine the extent to which on- and off-the-field training sessions can be used as training tools to improve offside decision-making.