Investigation of toppling ball flight in American football with a mechanical field-goal kicker

A mechanical field-goal kicking machine was used to investigate toppling ball flight in American football place-kicking, eliminating a number of uncontrollable impact variables present with a human kicker. Ball flight trajectories were recorded using a triangulation-based projectile tracking system to account for the football’s 3-dimensional position during flight as well as initial launch conditions. The football flights were described using kinematic equations relating to projectile motion including stagnant air drag and were compared to measured trajectories as well as projectile motion equations that exclude stagnant air drag. Measured football flight range deviations from the non-drag equations of projectile motion corresponded to deficits between 9 and 31%, which is described by a football toppling compound drag coefficient of 0.007 ± 0.003 kg/m. Independent variables including impact location and impact angle orientation resulted in 15 impact conditions. We found that an impact location of 5.5 cm from the bottom of the ball maximized trajectory height and distance. At the 5.5-cm impact location, alterations in impact angle produced minimal change in football trajectory, including launch angle (range = 1.96 deg), launch speed (range = 1.06 m/s), and range (range = 0.94 m).     

Political activity in escalation of commitment: Sport facility funding and government decision making in the United States

In the United States, the decision to commit extensive public resources to sport facilities is a contentious topic of debate. Elected officials often commit substantial public resources to sport facility projects amidst contrary empirical evidence and mixed residential approval. This behavior not only implicates the presence of political activity to advance a course of action, but also suggests an escalation of commitment (EoC), the subject of this study. The authors implemented a collective case study approach to examine three municipalities with long-standing histories of subsidizing professional sport facilities. Data collected from influential elected officials and public leaders (N = 13) as well as documents and records revealed (a) political action to be essential in EoC with decisions involving multiple stakeholder groups; (b) the influence and interaction of political action within each EoC determinant; (c) the substantial role of support, resources, power, and influence in efforts to increase and prevent commitment to a failing course of action; and (d) noticeable spillover effects from use of political activity in EoC.     

The Effects of Alternative Flowcharting Techniques on Performance on Procedural Tasks

Many individuals tend to have difficulty completing complex procedural tasks that require branching. Neither prose–based nor list–based instructions have been efficient in alleviating this difficulty. Traditional flowcharts have proven more effective in helping individuals to complete complex procedural tasks, but only after several practice sessions. However, it is possible that the use of map–like symbols may eliminate the need for repeated flowchart practice. Therefore, the purpose of this study was to investigate the effects of flowcharts utilizing map–like symbols on performer efficiency in completing a complex procedural task. The results of this study indicated no significant difference between the use of map–like symbols and traditional flowcharts in helping performers to complete complex procedural tasks. However, both graphic presentation formats were found to be significantly more efficient than a list–based presentation of information. It was expected than an intuitive map–like presentation would be more efficient than a list–based format. However, the efficiency of the flowchart presentation under unpracticed conditions was unexpected, based on prior research.     

Learning in Stereo: The Relationship Between Spatial Ability and 3D Digital Anatomy Models

Three-dimensional (3D) digital anatomical models show potential to demonstrate complex anatomical relationships; however, the literature is inconsistent as to whether they are effective in improving the anatomy performance, particularly for students with low spatial visualization ability (Vz). This study investigated the educational effectiveness of a 3D stereoscopic model of the pelvis, and the relationship between learning with 3D models and Vz. It was hypothesized that participants learning with a 3D pelvis model would outperform participants learning with a two-dimensional (2D) visualization or cadaveric specimen on a spatial anatomy test, particularly when comparing those with low Vz. Participants (n = 64) were stratified into three experimental groups, who each attended a learning session with either a 3D stereoscopic model (n = 21), 2D visualization (n = 21), or cadaveric specimen (n = 22) of the pelvis. Medical and pre-medical student participants completed a multiple-choice pre-test and post-test during their respective learning session, and a long-term retention (LTR) test 2 months later. Results showed no difference in anatomy test improvement or LTR performance between the experimental groups. A simple linear regression analysis showed that within the 3D group, participants with high Vz tended to retain more than those with low Vz on the LTR test (R² = 0.31, P = 0.01). The low Vz participants may be cognitively overloaded by the complex spatial cues from the 3D stereoscopic model. Results of this study should inform resource selection and curriculum design for health professional students, with attention to the impact of Vz on learning.