A quantitative hypothetico-deductive approach has continued to contribute greatly to advances in biological and medical science. Quantitative methods are adopted over other approaches primarily because they contribute the most new knowledge about biological processes. Nevertheless, investigators make many assumptions when testing a biological hypothesis quantitatively. These assumptions may become invalid unless experiments are designed with great care. Problems arise in relation to formulating appropriate hypotheses, using volunteer samples, controlling the experimental intervention and potentially interfering behaviors, reaching an acceptable level of proof, excluding alternative hypotheses, and generalizing findings beyond the immediate experimental sample. When biologists are aware of these issues, they can take appropriate countermeasures and reach valid conclusions. However, the issues become more critical and resolution is less clear-cut when the same methods are extended from biology to psychology and the social sciences, and from general to special populations. In such situations, case studies and single-subject designs may have continuing relevance.
Roy J. Shephard
Jill A. Bennett, Kerri Winters-Stone, Lillian M. Nail and Jennifer Scherer
This review describes the definitions of sedentary used to screen community-dwelling adults in physical-activity-intervention trials published from 2000 to 2005. Results of 42 trials showed that definitions of sedentary varied from <20 to <150 min/week of physical activity, and few reported the type (work, household, or leisure) or intensity of activity that was used to screen participants. The range of “sedentary” samples makes it difficult to compare trial results or generalize findings. Published reports of exercise trials would be more useful to practitioners and researchers if they included an explicit description of the cut point used to define sedentary adults in the sample, in terms of maximum minutes or days per week of activity and the wording of the screening measure in terms of type and intensity of activity.
Angela DiDomenico, Raymond W. McGorry and Jacob J. Banks
Time-to-contact (TtC) is an alternative measure of postural stability to center of pressure (CoP) velocity. TtC is based on both spatial and temporal aspects of CoP displacement, definition of the boundary shape, and quantity of minima analyzed. Three boundary shapes and three minima selection methods were used to compute TtC during bipedal quiet standing. The results suggest that there is a strong correlation between TtC values obtained using each of the calculation methods (r ≥.73) and mean CoP velocity (r ≥ −.70). TtC was significantly affected by boundary shape and minima selection method. This limits the ability to compare absolute values, but relative levels of stability computed using TtC can be compared due to strong correlations. Given the task parameters studied, mean CoP velocity may even be adequate to assess levels of stability. Future studies are needed to examine the generalizability of these findings for different groups and task parameters.
Olga J.E. Kilkens, Britt A.J. Gijtenbeek, Jos W.R. Twisk, Willem van Mechelen and Han C.G. Kemper
The purpose of this study was (a) to investigate whether lifestyle risk factors cluster and (b) to investigate the influence of this clustering on biological CVD risk factors. This study was part of the Amsterdam Growth and Health Study (AGHS), an observational longitudinal study in which 6 repeated measurements were carried out on 181 13-year-old subjects over a period of 15 years. A longitudinal analysis (carried out with generalized estimating equations) showed no significant clustering of lifestyle risk factors at the population level. For each subject at each separate measurement period, lifestyle risk factors were summed to form a cluster score. A longitudinal linear regression analysis showed no significant relationship between the cluster score and biological CVD risk factors, except for a significant inverse relationship with cardiopulmonary fitness. In general, however, the results did not support the assumption that clustering of unhealthy lifestyle is related to biological CVD risk factors.
To make scores from tests designed for special populations exchangeable, the tests must first be equated on the same scale. This study examined the utility of a Rasch model in equating motor function tasks. Using an existing gross motor function data set and a semisimulation design, an artificial equating and cross-validation sample, as well as two artificial tests, were created. Based on these samples and tests, the accuracy and stability of Rasch equating was empirically determined using a standardized difference statistic. It was found that Rasch equating could accurately equate tests and was generalizable when applied to a cross-validation sample. After equating, tests can be compared on the same scale, and interpretation of cross-test scores becomes possible. In addition, with the conversion table and graph generated from Rasch equating, the application of test equating was demonstrated as simple and practical.
Tara K. Scanlan, David G. Russell, Larry A. Scanlan, Tatiana J. Klunchoo and Graig M. Chow
Following a thorough review of the current updated Sport Commitment Model, new candidate commitment sources for possible future inclusion in the model are presented. They were derived from data obtained using the Scanlan Collaborative Interview Method. Three elite New Zealand teams participated: amateur All Black rugby players, amateur Silver Fern netball players, and professional All Black rugby players. An inductive content analysis of these players’ open-ended descriptions of their sources of commitment identified four unique new candidate commitment sources: Desire to Excel, Team Tradition, Elite Team Membership, and Worthy of Team Membership. A detailed definition of each candidate source is included along with example quotes from participants. Using a mixed-methods approach, these candidate sources provide a basis for future investigations to test their viability and generalizability for possible expansion of the Sport Commitment Model.
Herbert W. Marsh
The effects of participation in sport during the last 2 years of high school were examined by use of the nationally (United States) representative High School and Beyond data collected between 1980 and 1984. After background variables and outcomes collected during the sophomore year of high school were controlled for, sport participation positively affected 14 of 22 senior and postsecondary outcomes (e.g., social and academic self-concept, educational aspirations, course work selection, homework, reduced absenteeism, and subsequent college attendance) and had no negative effects on the remaining 8 variables. These positive effects were robust, generalizing across individual characteristics (race, socioeconomic status, sex, and ability level), school size, and school climates (academic, social, and sport). The positive effects of sport participation were mediated by academic self-concept and educational aspirations, supporting the proposal that sport participation enhances identification with the school.
Younghan Lee and Jakeun Koo
The current study used a 2 × 2 analysis to explore the effect of athlete endorser-product congruence and endorser credibility on consumer responses, such as attitude toward the advertisement, attitude toward the brand, and purchase intention. Real people and actual brands were used as stimuli to enhance external validity and generalizability. Research results confirmed the interaction effects between athlete endorser-product congruence and endorser credibility on three specific consumer responses. The research further examined and identified the indirect path from attitude toward the advertisement and purchase intention, mediated by attitude toward the brand. The findings from the research fill gaps in the literature and extend the body of knowledge in endorsement studies in general and sport celebrity-endorsement studies in particular.
Werner F. Helsen, Janet L. Starkes and Nicola J. Hodges
Two studies tested the theory of deliberate practice (Ericsson, Krampe, & Tesch-Romer, 1993) and contrasted results with the sport commitment model (Scanlan, Carpenter, Schmidt, Simons, & Keeler, 1993a, 1993b). In Part I, international, national, and provincial soccer and field hockey players recalled the amount of time they spent in individual and team practice, sport-related activities, and everyday activities at the start of their career and every 3 years since. In Part II, these activities were rated in terms of their relevance for improving performance, effort and concentration required, and enjoyment. A monotonic relationship between accumulated individual plus team practice and skill level was found. In contrast with Ericsson et al.’s (1993) findings for musicians, relevant activities were also enjoyable, while concentration became a separate dimension from effort. The viability of a generalized theory of expertise is discussed.
Yukyoum Kim, Hyun-Woo Lee, Marshall J. Magnusen and Minjung Kim
Sponsorship is a significant element of today’s marketing communication. Nevertheless, managers and researchers lack of systematic and integrative understanding of key factors that influence sponsorship outcomes and the contexts in which the relationships between sponsorship effectiveness antecedents and outcomes are stronger or weaker. The authors attempt to address this gap by providing a systematic meta-analytic review of sponsorship effectiveness that incorporates (1) cognitive, affective, and conative consumer-focused sponsorship outcomes; (2) sponsor-related, dyadic, and sponsee-related antecedents to consumer-focused sponsorship outcomes; and (3) sponsorship-related and methodological moderators of the relationships between the three antecedent categories and three outcome categories. Our findings help assess the validity and robustness of the predictive capability of the antecedents, and they also offer a more generalizable and empirically established set of factors that are vital to the achievement of key sponsorship outcomes. Several of our results afford noteworthy implications for improving the effectiveness of sponsorship research and practice.