Development and Validation of a Method for Determining Tridimensional Angular Displacements with Special Applications to Ice Hockey Motions

Abstract

Tridimensional angular displacements of the skates were determined with a single cinecamera used in conjunction with two orthogonal rods attached to the rear part of the skater's boots. The method was based on the commutative law with the imposed restrictions that two of the angles were small in relation to the other one, and that a sequence of angular displacements was defined. This approach required the sole determinations of the planar coordinates of the three points delimiting the orthogonal rods. An experimental setup was designed to validate the method: the criterion angles were approximated with less than 2 degrees of error. Subsequently, the method was applied to a practical situation: the two-legged stop in ice hockey. The combination of this tridimensional method with instrumented strain gauge skates for the measurement of forces provides a new and powerful tool for performing kinetic analyses in tridimensional skating activities.     

Social changes in youth sports participation styles 1969–1999: the case of Flanders (Belgium)

Three issues are put forward with respect to the active participation of young people in leisure-time sports styles. It is considered (a) whether sports participation styles can be detected over the last three decades, (b) whether they have changed in this period of time, and (c) whether traditional parameters understood as structuring and positioning young people's lifestyles are still relevant with respect to their sports participation preferences. Youth sports participation data were retrieved from four large-scale surveys in 1969, 1979, 1989 and 1999 (N_total=22,424 high school boys and girls). These data allow for a time trend analysis of youth sports participation styles. Results from component and regression analyses indicate that different participation styles can be distinguished for each period of time and that these styles have been developing and differentiating through a growing responsiveness to wider social trends. Structural and positioning variables such as age, sex and education remain significant determinants for young people's active participation in leisure-time sports styles over the observed period of time. Although these social structures continue to shape youth sports participation styles, it is suggested that there is more variety within social groups than among social groups partially due to processes of individualisation and homogenisation.     

Adolescent smoking from a functional perspective: The Berlin-Bremen Study

Longitudinal data from the «Berlin-Bremen Study on Health Behavior» are used to investigate smoking transitions between different stages of smoking. 1357 seventh and eighth graders were asked about their smoking behavior, their expectations with regard to smoking, smoking in their environment, and their self-image in Fall, 1983. 86% and 81% participated again one and two years later, respectively. Analyses of carbon monoxide and serum thiocyanate levels revealed adequate validity for self-reported smoking behavior. Rates of smoking were dramatically different for different educational strata. Direct and indirect functions of smoking are distinguished. The «indirect» function refers to smoking as a means of obtaining access to peer groups, thus increasing one’s psychological well-being. Direct functions refer to social and affective effects of smoking such as looking older or calming down. In line with expectations, indirect functions were found to be more important for younger adolescents and for smoking onset. In contrast, direct functions were better predictors of the smoking behavior of older adolescents and of the transition to regular smoking.     

Measurement of cognitive load in multimedia learning: a comparison of different objective measures

Different indicators are interesting for analyzing human learning processes. Recent studies analyze learning performance in combination with cognitive load, as an indicator for learners’ invested mental effort. In order to compare different measures of cognitive load research, the present study uses three different objective methods and one subjective method, reviewing the seductive details effect in a computer-based multimedia learning instruction. An experimental two-group design (N = 50) was used, with exposure to seductive details during learning as the between group factor. Eye movements were analyzed concerning the indicated cognitive activity and cognitive load was measured by the rhythm method (Park 2010; Park and Brünken 2015), the index of cognitive activity (ICA) (Marshall 2007), as well as by subjective ratings of mental effort and task difficulty (Paas 1992). Results confirm the seductive details effect for learning success with a decrease in retention and comprehension performance, an increase in total cognitive activity indicated by eye movements and significant higher cognitive load, indicated by rhythm method. The ICA values and the subjective ratings on mental effort and task difficulty show no difference in cognitive load between the groups. The results provide evidence of the suitability of different objective measures for a direct and continuous cognitive load assessment in multimedia learning. Further, the results show the benefit of combining different methods to gain detailed insight into information processing while learning with multimedia as well as a differentiated access to the single cognitive load factors.     

How emotionally intelligent are pre-service teachers?

Although there is evidence that teacher emotional intelligence is important for pupil adjustment and learning and for teachers in managing the emotional demands of their work, little is known about the levels of emotional skill of teachers and beginning teachers. Using Mayer and Salovey's emotional intelligence (EI) model and the MSCEIT test of EI, this study investigates how emotionally skilled student teachers are (N = 352). Results show lower than average levels of EI among student teachers, but with important differences between students and across emotional skill areas. The implications of the findings for pre-service teacher education are explored.