Search Results

You are looking at 51 - 60 of 415 items for :

  • "uncertainty" x
Clear All
Restricted access

Christoph Lienert, Claudine Sherrill and Bettye Myers

The purpose was to conduct a qualitative cross-cultural comparison of the concerns of physical educators in two countries about integration of children with and without disabilities. In-depth interviews were held with 30 regular elementary physical education teachers in Berlin (7 males, 9 females) and in the Dallas-Ft. Worth (DFW) area (2 males, 12 females), and observations were made of school settings. The Concerns-Based Adoption Model (CBAM) of Hall, Wallace, and Dossett (1973) guided the study. Data were analyzed by grounded theory procedures. Many concerns about integration were generalizable across cultures. In both countries, teachers reported concerns at only four of the seven stages of CBAM: personal, management, consequence, and collaboration. Most concerns focused on management. The major cultural difference was that DFW teachers reported more personal concerns (uncertainty about everyday demands and competence to meet these demands) than Berlin teachers. A dynamic systems model was proposed to guide future research.

Restricted access

David R. Collins, Hyeongsaeng Park and Michael T. Turvey

Von Holst (1939/1973) parsed intersegmental coordination into relative and absolute to distinguish moderate and extreme forms. Kelso and DeGuzman (1992) discussed an interpretation of relative coordination in terms of the chaotic phenomenon of intermittency. The data of concern (DeGuzman & Kelso, 1991) do not, however, exclude a stochastic interpretation, which is detailed here following earlier suggestions. The key difference is modeling relative coordination by stochastic variability about weak attractors rather than by deterministic variability about remnants of attractors (”ghost attractors”). The intermittency interpretation is not robust in the presence of noise and, therefore, is not well disposed to account for uncertainty in detailing a model of behavioral data or its parameters. In contrast, the stochastic interpretation is based upon an approximation of unknown underlying processes in the form of Gaussian white noise. A stochastic method for estimating model parameters from a stationary probability distribution and a mean first passage time is illustrated using experimental and simulated data.

Restricted access

Anne-Claire Macquet

This article reports on time management in an elite sports context. It aims at characterizing how coaches experience dealing with athletes’ time management in a sport and academic institute and their constraints. Ten male coaches participated in this study. Each coach was asked to describe his time management activity during the season. Inductive and deductive analysis revealed two main results. The first showed the coaches dealt with a stringent set of constraints concerned with: (a) season organization, (b) training period and task sequencing, (c) the institute’s set times, and (d) the uncertainty linked to the evolution of training. The second emphasized that the coaches used three complex operating modes: (a) the use of organizational routines based on reference to past experience, (b) season shared time management, and (c) time management based on flexible plans. The results are discussed in relation to research that has considered planning and time management.

Restricted access

Calum Mattocks, Andy Ness, Sam Leary, Kate Tilling, Steven N. Blair, Julian Shield, Kevin Deere, Joanne Saunders, Joanne Kirkby, George Davey Smith, Jonathan Wells, Nicholas Wareham, John Reilly and Chris Riddoch

Background:

Objective methods can improve accuracy of physical activity measurement in field studies but uncertainties remain about their use.

Methods:

Children age 11 years from the Avon Longitudinal Study of Parents and Children (ALSPAC), were asked to wear a uni-axial accelerometer (MTI Actigraph) for 7 days.

Results:

Of 7159 children who attended for assessment, 5595 (78%) provided valid measures. The reliability coefficient for 3 days of recording was .7 and the power to detect a difference of 0.07 SDs (P ≤ .05) was > 90%. Measures tended to be higher on the first day of recording (17 counts/min; 95% CI, 10–24) and if children wore the monitor for fewer days, but these differences were small. The children who provided valid measures of activity were different from those who did not, but the differences were modest.

Conclusion:

Objective measures of physical activity can be incorporated into large longitudinal studies of children.

Restricted access

Stefan Kesenne

This article uses economic theory to examine the variables that affect the competitive balance in a professional sports league and the impact of revenue sharing. The generally accepted proposition that revenue sharing does not affect the competitive balance in a profi t-maximizing league has been challenged by many. It is shown that the competitive balance and the impact of revenue sharing not only depend on the relative size of the market of the clubs, but that they are also affected by the objectives of the club owners and the importance to spectators of absolute team quality and uncertainty of outcome. Furthermore, the clubs’ hiring strategies, including the talent supply conditions, turn out to be important elements affecting competitive balance and the impact of revenue sharing.

Restricted access

Matthew D. Bird and Brandonn S. Harris

Sport psychology professionals have increasingly utilized technology for providing performance enhancement and clinical services. Some uncertainty exists amongst professionals to the ethical nature of providing services using technology. The purpose of this study was to survey Certified Consultants of the Association for Applied Sport Psychology (AASP) on the frequency and perceived ethicality of their technology use for providing performance enhancement and clinical services. A secondary purpose was to investigate differences in perceived ethicality between consultants with professional licensure compared to unlicensed professionals. Results suggest overall technology use for service delivery by consultants is low. Technologies used to provide clinical services displayed significantly lower ethical ratings compared to their use for performance enhancement purposes. Differences between licensed consultants and those who are unlicensed emerged for the ethical perceptions of providing performance enhancement services via email, cell phone, and videoconferencing, as well as for clinical services provided via cell phone.

Open access

Darren J. Burgess

Research describing load-monitoring techniques for team sport is plentiful. Much of this research is conducted retrospectively and typically involves recreational or semielite teams. Load-monitoring research conducted on professional team sports is largely observational. Challenges exist for the practitioner in implementing peer-reviewed research into the applied setting. These challenges include match scheduling, player adherence, manager/coach buy-in, sport traditions, and staff availability. External-load monitoring often attracts questions surrounding technology reliability and validity, while internal-load monitoring makes some assumptions about player adherence, as well as having some uncertainty around the impact these measures have on player performance This commentary outlines examples of load-monitoring research, discusses the issues associated with the application of this research in an elite team-sport setting, and suggests practical adjustments to the existing research where necessary.

Restricted access

Martin Gérin-Lajoie, Carol L. Richards and Bradford J. McFadyen

This article introduces a novel, ecological, obstructed walking paradigm. Gait adaptations to circumvent obstacles undergoing uncertain displacements, and the effect of revealing the obstacle’s action beforehand, were investigated in young adults. The personal space (PS) maintained during walking was quantified for the first time under different environmental factors including auditory distractions. Obstacle movement and its uncertainty resulted in gait adjustments aimed at gaining time to assess the situation. Early gait adaptations and constant clearances around the obstacle suggest that anticipation and preplanning are involved in such navigational tasks. Participants systematically maintained an elliptical PS during circumvention, but they adjusted its size according to different environmental factors. There was a relationship between the size of PS and level of attention, which suggests that the regulation of PS is used to control locomotion. This novel paradigm has important implications for the assessment and training of locomotor ability within real world environments.

Restricted access

Jenny McMahon and Kerry McGannon

This paper presents two meta-autoethnographies written by a former elite swimmer. In the first metaautoethnography, the swimmer revealed doubts in relation to details, emotions and inner-thoughts that she had included in her historical autoethnographic work. As a means of sorting and pondering these tensions and uncertainties, the swimmer explored cultural re-immersion as a possible additional element in the metaautoethnographic process. The second meta-autoethnography centers on the swimmer’s re-immersion into elite swimming culture. It was revealed how cultural re-immersion enabled the swimmer to better reflect on her historical autoethnographic work by providing a more conscientized, rational and reflexive voice. This research highlights how cultural re-immersion should be considered as an additional element in the metaautoethnographic process as it benefits both the author and also audience.

Restricted access

Luis Augusto Teixeira, Mariana Marília Franzoni and Juliana Bayeux da Silva

Movement reprogramming in a task requiring timing accuracy was investigated in young and elderly individuals. The task consisted of manually hitting a hemiball in synchrony with the arrival of a moving light stimulus running through an electronic trackway. Movement reprogramming was required by unexpectedly changing the regular stimulus velocity at different moments before the due time of arrival at the interception position. Such changes produced times after velocity decrease (TAVD) between 150 ms and 750 ms, representing the periods of time available for generation of new movement timing specifications. Effect of probability of stimulus velocity change was investigated by comparing the conditions of 25% and 50% of chance of velocity decrease. Analysis of performance in conditions of velocity decrease showed an enlargement of temporal error as a function of longer TAVDs up to 300-375 ms. In conditions in which TAVDs were longer than 375 ms young participants showed a progressive improvement of accuracy over time, while the elderly were unable to improve their performance even for a TAVD of 750 ms. A trend toward a more efficient reprogramming with reduced uncertainty was observed only in the young. These results indicate that movement reprogramming is a continuous process in young individuals, but it is impaired in the elderly, preventing an appropriate reorganization of the action.