original simulation using a padded (∼30 kg) tackle bag impaired the external validity of such simulations. 6 , 9 The use of a tackle bag to replicate contact also increases the overall running speed as a consequence of a faster approach to the collision and results in less neuromuscular fatigue when
Jonathan P. Norris, Jamie Highton and Craig Twist
David A. Rowe, Thomas D. Raedeke, Lenny D. Wiersma and Matthew T. Mahar
The purpose of the study was to investigate the measurement properties of questionnaires associated with the Youth Physical Activity Promotion (YPAP) model. Data were collected from 296 children in Grades 5–8 using several existing questionnaires corresponding to YPAP model components, a physical activity questionnaire, and 6 consecutive days of pedometer data. Internal validity of the questionnaires was tested using confirmatory factor analyses, and external validity was investigated via correlations with physical activity and body composition. Initial model fit of the questionnaires ranged from poor to very good. After item removal, all scales demonstrated good fit. Correlations with percentage body fat and objectively measured physical activity were low but in the theoretically predicted direction. The current study provides good internal validity evidence and acceptable external validity evidence for a brief set of questionnaire items to investigate the theoretical basis for the YPAP model.
Iina Antikainen and Rebecca Ellis
Although physical activity interventions have been shown to effectively modify behavior, little research has examined the potential of these interventions for adoption in real-world settings. The purpose of this literature review was to evaluate the external validity of 57 theory-based physical activity interventions using the RE-AIM framework. The physical activity interventions included were more likely to report on issues of internal, rather than external validity and on individual, rather than organizational components of the RE-AIM framework, making the translation of many interventions into practice difficult. Furthermore, most studies included motivated, healthy participants, thus reducing the generalizability of the interventions to real-world settings that provide services to more diverse populations. To determine if a given intervention is feasible and effective in translational research, more information should be reported about the factors that affect external validity.
Tara K. Scanlan, David G. Russell, T. Michelle Magyar and Larry A. Scanlan
The Sport Commitment Model was further tested using the Scanlan Collaborative Interview Method to examine its generalizability to New Zealand’s elite female amateur netball team, the Silver Ferns. Results supported or clarified Sport Commitment Model predictions, revealed avenues for model expansion, and elucidated the functions of perceived competence and enjoyment in the commitment process. A comparison and contrast of the in-depth interview data from the Silver Ferns with previous interview data from a comparable elite team of amateur male athletes allowed assessment of model external validity, tested the generalizability of the underlying mechanisms, and separated gender differences from discrepancies that simply reflected team or idiosyncratic differences.
Maria Hagströmer, Barbara E. Ainsworth, Lydia Kwak and Heather R. Bowles
The quality of methodological papers assessing physical activity instruments depends upon the rigor of a study’s design.
We present a checklist to assess key criteria for instrument validation studies.
A Medline/PubMed search was performed to identify guidelines for evaluating the methodological quality of instrument validation studies. Based upon the literature, a pilot version of a checklist was developed consisting of 21 items with 3 subscales: 1) quality of the reported data (9 items: assess whether the reported information is sufficient to make an unbiased assessment of the findings); 2) external validity of the results (3 items: assess the extent to which the findings are generalizable); 3) internal validity of the study (9 items: assess the rigor of the study design). The checklist was tested for interrater reliability and feasibility with 6 raters.
Raters viewed the checklist as helpful for reviewing studies. They suggested minor wording changes for 8 items to clarify intent. One item was divided into 2 items for a total of 22 items.
Checklists may be useful to assess the quality of studies designed to validate physical activity instruments. Future research should test checklist internal consistency, test-retest reliability, and criterion validity.
Brent L. Arnold
David E. Conroy, Andrew J. Elliot and Scott M. Hofer
Achievement goals in sport have traditionally been defined according to the definition of competence alone (i.e., mastery/task, performance/ego). Emerging research and theory from the academic domain indicates that the utility of the achievement goal construct can be enhanced when the valence (i.e., approach, avoidance) of goals is also considered in conjunction with the definition of competence. The present study was designed to evaluate the psychometric properties of scores for mastery-approach, mastery-avoidance, performance-approach, and performance-avoidance goals from a measure of achievement goals in sport. The a priori 2 × 2 model fit the data better than any of the plausible alternative models. In a series of longitudinal factorial invariance and latent growth curve analyses, scores for the four subscales exhibited structural invariance, and both differential and latent mean stability over a 21-day period. Achievement goal scores conformed to theoretical predictions regarding their relationship with fear-of-failure scores. The AGQ-S would be an appropriate instrument for future research using the 2 × 2 model of achievement goals in sport, particularly for experimental/intervention research on change processes associated with achievement goals.
Colleen A. Cuthbert, Kathryn King-Shier, Dean Ruether, Dianne M. Tapp and S. Nicole Culos-Reed
Family caregivers are an important health care resource and represent a significant proportion of Canadian and US populations. Family caregivers suffer physical and psychological health problems because of being in the caregiver role. Interventions to support caregiver health, including physical activity (PA), are slow to be investigated and translated into practice.
To examine the evidence for PA interventions in caregivers and determine factors hampering the uptake of this evidence into practice.
A systematic review and evaluation of internal and external validity using the RE-AIM (Reach, Efficacy/Effectiveness, Adoption, Implementation, and Maintenance) framework was conducted. Randomized controlled trials or pretest/posttest studies of PA interventions were included.
Fourteen studies were published between 1997 and 2015. Methodological quality of studies and risk of bias was variable. External validity criteria were often not reported. Mean reporting levels were 1) reach, 53%; 2) efficacy/effectiveness, 73%; 3) adoption, 18%; 4) implementation, 48%; and 5) maintenance, 2%.
The lack of reporting of components of internal and external validity hinders the integration of caregiver PA interventions into clinical or community settings. Researchers should focus on standardized outcomes, accepted reporting criteria, and balancing factors of internal and external validity, to advance the state of the science.
Henning Plessner and Tilmann Betsch
In their comments on a study on penalty decisions in soccer (Plessner & Betsch, 2001), Mascarenhas, Collins, and Mortimer (2002) point to several factors that, in their view, weaken the external validity of this laboratory study. In our response, we argue that although it may be helpful to substantiate the prior findings in a study closer to the natural setting of refereeing, Mascarenhas et al. provide no conclusive argument as to why the observed judgment biases should vanish under more realistic conditions.
Tara K. Scanlan, David G. Russell, Noela C. Wilson and Larry A. Scanlan
We present an application of the Scanlan Collaborative Interview Method (SCIM) to the Project on Elite Athlete Commitment (PEAK). PEAK examines three samples of elite international athletes to further test and expand the Sport Commitment Model and assess its external validity. This first article in the series provides detailed descriptions of the study rationale, methods, procedures, interview schedule, and analysis strategy common to the three samples, along with participant characteristics and selection criteria. It also shares participants’ observations of the centrality of commitment to their athletic success, and their evaluation of the interview process.