Comparison of the Standard and Reliability of the Assessments of Practical Scientific Skills using Groups of Different Sizes

The investigation set out to determine whether there were significant differences in marking standard and reliability when experienced teachers carried out assessments of the performance on practical exercises using groups containing five and twenty students, respectively. The investigation was performed by allocating eight teachers randomly and evenly to two panels, one of which assessed a random group of five fourth‐year secondary students before assessing a random group of 20, and the other working with different randomly selected groups of the same size, but in the different order. The results showed that for both marking standard and reliability there was no significant difference between the assessments from the groups of the two sizes with the vast majority of individual tasks assessed.     

Books and Publishing

Thomas Whiteside, THE BLOCKBUSTER COMPLEX: CONGLOMERATES, SHOW BUSINESS, AND BOOK PUBLISHING (MiddletOwn, Conn., 1981---$12.95)

John Dizer, Jr., TOM SWIFT & COMPANY: "BOY'S BOOKS" BY STRATEMEYER AND OTHERS (McFarland & Co. Inc., Box 611, Jefferson, N.C. 28640---$17.95)

Roy Harley Lewis, THE BOOK BROWSER'S GUIDE TO SECONDHAND AND ANTIQUARIAN BOOKSHOPS (North Pomfret, Vt.: David & Charles, 1982---$23.50)

Linda S. Hubbard, ed. BOOK PUBLISHERS DIRECTORY (Detroit; Gale Research, 1981---$160)     

Luge track safety

Simple geometric models of ice surface shapes and equations of motion of objects on these surfaces can be used to explain ejection of sliders from ice tracks. Simulations employing these explain why certain design features can be viewed as proximate causes of ejection from the track and hence design flaws. This paper studies the interaction of a particle model for the luge sled (or its right runner) with the ice fillet commonly connecting inside vertical walls in turns to the flat track bottom. A numerical example analyzes the 2010 luge accident at the Vancouver Olympics. It shows that this runner-fillet interaction, and specifically the fillet’s positive curvature up the inside wall, can cause a vertical velocity more than sufficient to clear the outside exit wall. In addition the negative curvature of the fillet along the track and the large vertical velocity, explain loss of fillet or wall contact and slider ejection. This exposes the fillet along inside walls as a track design flaw. A more transparent track design and review process could provide more complete and thorough design and verification scrutiny by competent scientists and engineers without financial involvement or conflicts of interest and potentially lead to safer future designs.     

A Gendered Look at Educational Reform

This article looks at women teachers' involvement in educational reform from a gendered perspective. Using qualitative data collected in interviews with secondary level educators, the authors show how women teachers' beliefs and actions towards reform efforts were influenced by their gender identity. Socialization of women as nurturers and caretakers created in many women particular notions regarding the appropriate role they should play as teachers. When an educational reform effort 'fitted' with these conceptions, women teachers became advocates for and participated in the reforms. The support and commitment by women teachers in turn facilitated the success of the reforms. However, it was also found that the overrepresentation of women in a reform effort had the potential of creating negative political ramifications. When the character or profile of the reform took on a gendered identity, it ran the risk of facing resistance by men teachers in the school, ultimately thwarting implementation.     

Pedagogical content knowledge in computing education: a review of the research literature

This review synthesizes literature on computing pedagogical content knowledge (PCK). Shulman introduced PCK in the 1980s to describe the amalgam of knowledge teachers draw upon in their work and use of the construct is increasing in the computing education community. From a systematic search of the literature, I identified 19 articles drawn from 9 countries for review and summarize how computing PCK is conceptualized and investigated in the data set. Five conceptualizations of computing PCK were present: (a) two models of computing PCK components, (b) one model of PCK development and (c) two models focused on the metaphoric and problem-solving nature of computing. The most common research lines addressed were the nature and development of individual PCK. Mostly qualitative methods created by authors were employed. A focus on discipline-specific approaches for future computing PCK research is recommended.     

Experimental determination of baseball spin and lift

The aim of this study was to develop a new method for the determination of lift on spinning baseballs. Inertial trajectories of (a) ball surface markers during the first metre of flight and (b) the centre of mass trajectory near home-plate were measured in a pitch using high-speed video. A theoretical model was developed, incorporating aerodynamic Magnus-Robins lift, drag and cross forces, which predicts the centre of mass and marker trajectories. Parameters including initial conditions and aerodynamic coefficients were estimated iteratively by minimizing the error between predicted and measured trajectories. We compare the resulting lift coefficients and spin parameter values with those of previous studies. Lift on four-seam pitches can be as much as three times that of two-seam pitches, although this disparity is reduced for spin parameters greater than 0.4.     

Experimental determination of baseball spin and lift

The aim of this study was to develop a new method for the determination of lift on spinning baseballs. Inertial trajectories of (a) ball surface markers during the first metre of flight and (b) the centre of mass trajectory near home-plate were measured in a pitch using high-speed video. A theoretical model was developed, incorporating aerodynamic Magnus-Robins lift, drag and cross forces, which predicts the centre of mass and marker trajectories. Parameters including initial conditions and aerodynamic coefficients were estimated iteratively by minimizing the error between predicted and measured trajectories. We compare the resulting lift coefficients and spin parameter values with those of previous studies. Lift on four-seam pitches can be as much as three times that of two-seam pitches, although this disparity is reduced for spin parameters greater than 0.4.     

Addressing the Language and Cultural Problems of Overseas Students in the Context of Mathematics Classes

This paper describes a project in which instruction in mathematical language and strategies for adapting to the Australian university environment were integrated into mathematics classes. The classes were part of a program which enables overseas students to meet the entry requirements of Australian business faculties. The project used the action research methodology in which observations of the students' reactions motivated further activities. The outcomes of the project are described using the diary entries made by students, teacher and observer. These show that students developed an awareness of the need to improve their language skills and to make cultural adjustments and made some progress in these directions.