Different centre of pressure patterns within the golf stroke I: Cluster analysis

Weight transfer research in the golf swing has produced conflicting and inconclusive results. A limitation of previous studies is the assumption that only one swing "style" exists within the golf swing. If different styles, or movement strategies, exist and if the different styles are analysed together in a single group, statistical errors will result. The aim of this study was to determine if different weight transfer styles exist in the golf swing by applying cluster analysis to centre of pressure (CP) patterns in the direction of hit (CPy) and to evaluate cluster analysis issues. Sixty-two professional to high handicap golfers performed simulated drives, hitting a golf ball into a net, while standing on two force plates. Centre of pressure position relative to the feet (CPy%) was quantified at eight swing events identified from 200-Hz video. Cluster analysis identified two major CPy% styles: a "Front Foot" style and a "Reverse" style. Both styles began with CPy% positioned evenly between the feet, moved to the back foot during backswing, and then forward during early downswing. Beyond early downswing, the Front Foot group continued to move CPy% to the Front Foot through to ball contact, while the Reverse group moved CPy% towards the back foot through ball contact and follow-through. Both weight transfer styles were evident across skill levels from professional to high handicap golfers, indicating that neither style was a technical error. Cluster analysis should include hierarchical and non-hierarchical clustering and use objective measures combined with theoretical assessment to determine the optimal number of clusters. Furthermore, a number of validation procedures should always be used to validate the solution.     

On referee bias, crowd size, and home advantage in the English soccer Premiership

In a recent paper in this journal, Boyko and colleagues (2007) identified differences in attendance and referee bias as factors influencing home advantage at soccer matches in the English Premiership. A replication of their study using more recent data found no evidence to sustain either of their claims.     

Writing for Social Scientists: How to Start and Finish Tour Thesis,Book, or Article.

Underlined by the belief that teachers' critical awareness of their actions is a vital issue in education, this study examines the insights that evolved from a long-term collaboration among seven doctoral students. To prepare for our comprehensive examinations, we collaborated as a study group for one and one-half years. Adopting the dual roles of listener-researcher and narrator-participant, we engaged in dialogue and narrative to convey to each other the meaning of our collaborative experiences. From grounded theory analysis, four elements of collaboration emerged: logistics, social dynamics, empowerment, and change. In order to convey the meaning of our experiences, we create a multiplicity of meanings based on our diverse and lived personal narratives. Finally, our collaborative process challenges academic administrations to examine how well their current policies encourage personal autonomy and cooperative learning approaches for students involved in preparing for their comprehensive examinations.     

Children's motivation in elementary physical education: an expectancy-value model of achievement choice

This study examined children's motivation in elementary physical education within an expectancy-value model developed by Eccles and her colleagues. Four hundred fourteen students in second and fourth grades completed questionnaires assessing their expectancy-related beliefs, subjective task values, and intention for future participation in physical education. Results indicated that expectancy-related beliefs and subjective task values were clearly distinguishable from one another across physical education and throwing. The two constructs were related to each other positively. Children's intention for future participation in physical education was positively associated with their subjective task values and/or expectancy-related beliefs. Younger children had higher motivation for learning in physical education than older children. Gender differences emerged and the findings provided empirical evidence supporting the validity of the expectancy-value model in elementary physical education.