Getting from Here to There: The Roles of Policy Makers and Principals in Increasing Science Teacher Quality

In this study we investigate how federal and state policy makers, and school principals are working to improve science teacher quality. Interviews, focused discussions, and policy documents serve as the primary data source. Findings suggest that both policy makers and principals prioritize increasing incentives for teachers entering the science teaching profession, providing professional development for new teachers, and using students’ data to evaluate and improve instruction. Differences between the two leadership groups emerged in terms of the grain size and practicality of their concerns. Our findings indicate that the complexity of educational challenges to improve science teacher quality call for the co-construction of policy by multiple constituent groups including school principals, federal and state policy makers, and science education researchers.     

Age-related differences in the control of spatial aiming movements.

The experiment was designed to (a) examine age-related differences in the control of aiming movements, and (b) determine the locus of slowing in movement execution of older adults. Fitts's (1954) index of difficulty (ID) was used to manipulate movement execution demands, and kinematics were used to examine the response characteristics. Twelve young and 12 older adults performed simple aiming movements 10 cm or 20 cm in amplitude to targets of 0.5 cm, 1.0 cm, or 2.0 cm in width, resulting in IDs ranging from 3.32 to 6.32. The results for both young and older subjects support the prediction that movement time (MT) increases as a function of ID and that older adults are significantly slower and more affected by increases in ID than the young adults. Velocity and acceleration profiles of the older adults' movements displayed very different response characteristics than those of the young adults. The results suggest that older adults emphasize accuracy of response and are concerned with the latter phase of the movement in order to contact a target accurately.     

Alzheimer's Disease and Other Dementias: An Organizational Approach to Identifying and Addressing Practices and Learning Needs of Family Physicians

ABSTRACT

Caring for patients with dementia is complex and demanding. Since family physicians (FPs) provide much of this care, we examined their practices, learning needs, and barriers to care concerning Alzheimer's disease and other dementias. We surveyed 392 (approximately 50%) Nova Scotia FPs and conducted focus groups and interviews with: FPs; staff of long-term care facilities; health professionals in home care; patients and their caregivers; FPs with advanced geriatric training; geriatricians; and psychiatrists. Results suggest that many FPs do not perform assessment and management practices as frequently as they ideally should. However, systemic factors, not only inadequate knowledge, affect care.     

The logic of inference in criminal justice statistics

An approach to teaching criminal justice statistics is advanced that focuses on broad similarities between all inferential tests. Tests of inference include all processes in which a hypothesis is generated and, ultimately, rejected or not. The process of a criminal trial, which is an inferential test, is employed as an extended analogy, through which specific statistical concepts are introduced. The advantages to criminal justice students of learning statistical concepts through a justice-specific framework are discussed.     

Explosive force production during isometric squats correlates with athletic performance in rugby union players

Abstract

This study investigated the association between explosive force production during isometric squats and athletic performance (sprint time and countermovement jump height). Sprint time (5 and 20 m) and jump height were recorded in 18 male elite-standard varsity rugby union players. Participants also completed a series of maximal- and explosive-isometric squats to measure maximal force and explosive force at 50-ms intervals up to 250 ms from force onset. Sprint performance was related to early phase (≤100 ms) explosive force normalised to maximal force (5 m, r = ?0.63, P = 0.005; and 20 m, r = ?0.54, P = 0.020), but jump height was related to later phase (>100 ms) absolute explosive force (0.51 < r < 0.61; 0.006 < P < 0.035). When participants were separated for 5-m sprint time (< or ≥ 1s), the faster group had greater normalised explosive force in the first 150 ms of explosive-isometric squats (33–67%; 0.001 < P < 0.017). The results suggest that explosive force production during isometric squats was associated with athletic performance. Specifically, sprint performance was most strongly related to the proportion of maximal force achieved in the initial phase of explosive-isometric squats, whilst jump height was most strongly related to absolute force in the later phase of the explosive-isometric squats.     

Reaction Time Analysis of Programed Control of Short,Rapid Aiming Movements

Reaction time, fractionated reaction time (premotor and motor time), and movement time were recorded during performance of a rapid aiming movement (11 mm in amplitude) to a circular target. Independent variables were target diameter (2 or 64 mm) and reaction time condition (simple or choice). Fifty-two subjects performed 16 practice and 24 performance trials under one of four possible experimental combinations (13 subjects per combination) in a 2 × 2 design. Reaction time correlated highly with premotor time (r = .99) but not with motor time (r = .31). Choice reaction time and its premotor time component were dependent upon target diameter, but simple reaction time and its premotor time component were not. However, choice and simple motor time were not differentially affected by target diameter. As expected, movement time was longer for the small target than for the large target. Taken together, the reaction time results were interpreted as support for Klapp's (1975) hypothesis that increases in choice reaction time for rapid movements to a small target are due to increases in the time needed for programing the response.     

Psychophysics of arm movements and human aging.

The purpose of this study was to investigate possible age-related differences in the physical stimulus-psychological response relationship. Young and older adult subjects moved their arm to three standard locations or extents (25 cm, 50 cm, and 75 cm) on a linear positioning device. Seven standard comparison combinations were presented 20 times each. Subjects were asked to determine whether the comparison was different from the standard. Just noticeable difference, constant error, absolute constant error, and Weber ratios were calculated. In contrast to previous studies, the results clearly indicate that the physical stimulus-psychological response magnitude relationship for location and extent movements is best described by a metathetic continuum. We offer an explanation to account for the differences between location and extent movements for the just noticeable difference and Weber ratio. The failure to find differences between the age groups suggests that age-related declines cannot be generalized to all perceptual systems.     

A study of quadratic cost functions for vehicle headway control

This paper shows that minimizing a quadratic cost function is not particularly useful for selecting a small number of controller gains in vehicle headway control. For cases in which a large number of controller gains are to be selected, the quadratic cost function may be useful, but the weighting parameter values cannot usually be chosen a priori if transient performance measures are of a particular interest. Examples illustrate how values of weights in a simplified cost function can be selected to yield acceptable transient performance. This performance is compared with that for a system containing only a few gains and optimized without recourse to a cost function.