Volleyball

The purpose of this investigation was to detect whether differences exist concerning the dynamic and kinematic parameters of vertical squat jump (SJ) on rigid (RS) and sand (SS) surface. Fifteen elite male beach volleyball players (age: 25.6±6.2 years; height: 188.0±3.5cm; body mass: 83.2±6.0 kg; mean ±SD, respectively) performed SJ. Force platform and kinematic analyses were used with paired sample T‐tests to evaluate the differences. Vertical jump height was significantly smaller (p < .001) on SS than RS. Maximal force and maximal power were significantly higher on RS than SS (p < .05 and p < .01 respectively). Impulse time was larger in SS but with no significant difference (p = .286). Kinematic analysis revealed significant differences between the values of ankle joint during starting posture (p < .01) and of hip joint at the moment of take‐off (p < .05). Ankle joint range of motion and angular velocity was larger in SS (p < .05). In conclusion, SJ height on SS was smaller than on RS because of the compliance and the instability of the sand. This resulted in a reduction in maximum force and take‐off velocity. Furthermore, the compliance of SS made it hard for the ankle to push along the vertical axis of the movement of the body and as a result it slipped behind in an attempt to maximise propulsion. As a result, the body tries to balance and equalise this movement and move the hip to larger extension.     

Using Nikola Tesla’s Story and His Experiments as Presented in the Film “The Prestige” to Promote Scientific Inquiry: A Report of an Action Research Project

This paper reports on an action research project undertaken with the primary aim of investigating the extent to which situations that evoke a sense of wonder can promote scientific inquiry. Given the intense interest, curiosity, and wonder that some students had begun to develop after seeing the film The Prestige, a science teacher used this film, which showed Tesla’s demonstrations on the wireless transmission of electrical power, as a source of curiosity and wonder. The class that participated in this action research project was an 11^th grade class in a rural area of southern Greece. Through an analysis of students’ journals, observation, informal discussions, and paper-and-pencil tests, it was found that students (a) became involved with Tesla’s life and work, thus developing an interest in current electricity; (b) learned about the skin effect, the biological effects of AC and DC currents; and (c) better understood Ohm’s law in their attempt to find out the degree of damage or injury a certain measure of current can cause. Moreover, some students began to develop scepticism and open-mindedness, in addition to their sense of wonder. The paper also presents a planning framework for teaching the Tesla story.     

Revealing latent traits in the social behavior of distance learning students

Education and Information Technologies - This paper proposes a multilayered methodology for analyzing distance learning students’ data to gain insight into the learning progress of the...     

Preschool Teachers’ Understandings of the National Preschool Curriculum in Greece

In 2003, a new curriculum was enacted in Greek preschool education, replacing the previous one of 1989 and following the development of new curricula for the other rungs of compulsory education. Within this context, the new curriculum development policy aimed at an equal integration of preschool education into the unified design of primary and secondary education. A basic issue in any such educational change is how teachers make sense of the new curriculum and what impact it has on their thinking and daily practice. Considering the need to better understand the relationships between curriculum and parameters that shape practice, the study examines preschool teachers’ perspectives of the new early childhood curriculum and its implementation, as well as the extent to which the new curriculum has influenced preschool practices.