A Distribution Free Interval Estimate for Coefficient Alpha

Scales are important tools for obtaining quantitative measures of theoretical constructs. Once a set of measures to be used in a scale is selected, reliability is commonly examined in order to assess their measurement quality. To date, Cronbach’s coefficient alpha is the most commonly reported index of measurement quality for assessing scale reliability. In this paper, an asymptotic distribution of the natural estimator of coefficient alpha is derived. A new interval estimate and a statistical test on the significance of the sample estimate of the coefficient are also presented. The proposed approach is compared to four popular methods commonly used to compute confidence intervals (CI) for alpha using a Monte Carlo simulation study. An R function for implementing the proposed CI approach is also provided.     

Evaluation of Food Protection and Defense Outreach Education Programs

ABSTRACT: This analysis documents the outcomes and impacts from a series of food protection and defense educational programs conducted over a 3‐y period for private and public sector food system professionals. Several measures were used to determine the professions of participants; their improvements in skills and abilities that resulted from workshops; the audiences' most valued program content; practice changes resulting from educational program participation; abilities to recognize and change food system vulnerabilities; and changes in knowledge levels. Findings indicate that the knowledge level and interest within the target audience progressed over the 3‐y period from basic awareness level through more complex and higher order skills and competencies such as being able to walk through a food production, processing, distribution, or retail facility and identify specific vulnerabilities and make specific risk control recommendations. Pre‐ and posttest scores from the 3rd y of educational activities indicate that baseline awareness levels of core content on food protection and defense is now high among those most likely to attend these types of events, and that participants need to be challenged with additional higher‐level education to promote specific skills. This program series proved successful in building important relationships among food industry and regulatory partners. Analysis of the food security investigation (FSI) series will be useful in the development and delivery of new education and outreach efforts. It is hoped that the analysis and discussion will provide the motivation to further develop a set of competencies that can be used to ground educational efforts that focus on securing and defending our food system.     

Force-velocity characteristics of upper limb extension during maximal wheelchair sprinting performed by healthy able-bodied females

The aim of this study was to determine the relationship between force and velocity parameters during a specific multi-articular upper limb movement--namely, hand rim propulsion on a wheelchair ergometer. Seventeen healthy able-bodied females performed nine maximal sprints of 8 s duration with friction torques varying from 0 to 4 N x m. The wheelchair ergometer system allows measurement of forces exerted on the wheels and linear velocity of the wheel at 100 Hz. These data were averaged for the duration of each arm cycle. Peak force and the corresponding maximal velocity were determined during three consecutive arm cycles for each sprint condition. Individual force-velocity relationships were established for peak force and velocity using data for the nine sprints. In line with the results of previous studies on leg cycling or arm cranking, the force-velocity relationship was linear in all participants (r = -0.798 to -0.983, P < 0.01). The maximal power output (mean 1.28 W x kg(-1)) and the corresponding optimal velocity (1.49 m x s(-1)) and optimal force (52.3 N) calculated from the individual force-velocity regression were comparable with values reported in the literature during 20 or 30 s wheelchair sprints, but lower than those obtained during maximal arm cranking. A positive linear relationship (r = 0.678, P < 0.01) was found between maximal power and optimal velocity. Our findings suggest that although absolute values of force, velocity and power depend on the type of movement, the force-velocity relationship obtained in multi-articular limb action is similar to that obtained in wheelchair locomotion, cycling and arm cranking.     

A Cross-Sectional Test of Sign Creation by Children in the Gesture and Vocal Modalities

Naturalistic studies show that children can create language-like communication systems in the absence of conventional language. However, experimental evidence is mixed. We address this discrepancy using an experimental paradigm that simulates naturalistic sign creation. Specifically, we tested if a sample of 6- to 12-year-old children (52 girls and 56 boys drawn from an urban, predominantly white population in Western Australia) can comprehend and create novel gestural and vocal signs. Experiment 1 tested children’s ability to comprehend novel signs. Experiment 2 tested children’s ability to create novel signs. Results show that children can comprehend and create gestural and vocal signs, that communication is more successful in the gesture modality, and that older children outperform younger children.     

Young people,education and unlawful non‐citizenship: spectral sovereignty and governmentality in Australia

This paper considers Judith Butler’s discussion of the intersections between governmentality and sovereign power in Precarious life: the powers of mourning and violence. We consider this interrelationship with a view to considering how this might enable us to expand our understanding of contemporary discourses governing young people within and outside Australia. In particular we focus on the production of groups of young people, such as those classified as ‘illegal immigrants’ who may be situated outside the frame of ‘public good’ or the ‘private interest’. This enables for a theorisation of the lives of groups of young people who may ‘have no definitive prospect for a re‐entry into the political fabric of life, even as one’s situation is highly, if not fatally, politicized’. It is questionable whether the Foucauldian notion of governmentality gives sufficient account of the lives of these young people whose conduct is effectively considered irrelevant by the State. As educators, it is arguable that we have an ethical imperative to encourage our students to care for themselves, and for others, especially those others whose lives have been ‘fatally politicized’.     

The process of understanding the task: how is agency distributed between students, teachers and representations in technology-rich learning environments?

In this article, we explore how students’ agency relates to both highly structured and open-ended learning environments. This is done by analysing how students’ understanding of tasks evolves through their activities in relation to the representations inscribed in two technology-rich learning environments. Based on the sociocultural approach to thinking, reasoning and learning we argue that it is necessary to include activities, artefacts and aspects of the knowledge domain in order to understand how and what the students’ learn. We conclude by arguing that the process of understanding a task is often complex and ongoing through the activity.