Spurious Latent Classes in the Mixture Rasch Model

Mixture Rasch models have been used to study a number of psychometric issues such as goodness of fit, response strategy differences, strategy shifts, and multidimensionality. Although these models offer the potential for improving understanding of the latent variables being measured, under some conditions overextraction of latent classes may occur, potentially leading to misinterpretation of results. In this study, a mixture Rasch model was applied to data from a statewide test that was initially calibrated to conform to a 3‐parameter logistic (3PL) model. Results suggested how latent classes could be explained and also suggested that these latent classes might be due to applying a mixture Rasch model to 3PL data. To support this latter conjecture, a simulation study was presented to demonstrate how data generated to fit a one‐class 2‐parameter logistic (2PL) model required more than one class when fit with a mixture Rasch model.     

Teaching Science Inquiry in Urban Contexts: The Role of Elementary Preservice Teachers’ Beliefs

This paper reports on a study of elementary preservice teachers’ inquiry-based practices, their efficacy beliefs, and the role beliefs had on two preservice teachers’ practices in urban classrooms. Results show inquiry-based practices can be cultivated through field-based experiences and preservice teachers’ efficacy beliefs, as it relates to practice in urban settings, are malleable. Specifically, personal efficacy beliefs about teaching science improved or were sustained for one cohort of preservice teachers. However, beliefs about students’ ability to learn science, that is outcome beliefs, were less stable. The results of two case studies show that science content knowledge was a factor in preservice teachers’ inquiry-based practices. However, why preservice teachers’ beliefs about student learning declined is less clear. More research is needed, along with follow-up data on teacher induction, to learn how preservice teachers’ beliefs impact urban students’ science education.     

Team-based learning in anatomy: an efficient, effective, and economical strategy

Team-based learning (TBL) strategy is being adopted in medical education to implement interactive small group learning. We have modified classical TBL to fit our curricular needs and approach. Anatomy lectures were replaced with TBL that required preparation of assigned content specific discussion topics (in the text referred as "discussion topics"), an individual self-assessment quiz (IRAT), analysis of the discussion topics, and then the team retaking the same quiz (GRAT) for discussion and deeper learning. Embryology and clinical correlations were given as lectures. Unit examinations consisted of graded IRAT and GRAT. The National Board of Medical Examiners (NBME) Subject Examination was the comprehensive final examination. To evaluate the effect of TBL on student performance we compared the departmental and NBME subject examination scores between the traditional and TBL curricula. We collected five years of data on student performance in TBL-based anatomy and lecture-based preclinical courses. Our results show that departmental and NBME subject examination scores for TBL-based anatomy were higher than those for lecture-based anatomy. We subsequently compared average NBME scores for anatomy with those in other preclinical courses that were lecture-based. Average NBME anatomy scores were significantly higher than those for all the lecture-based preclinical courses. Since the introduction of TBL in anatomy, student performance has progressively improved in the NBME subject examination. Students perceived TBL as a motivator to be a responsible team member and to contribute to collective learning by the team. Further, it reinforced self-directed learning and fostered an appreciation for peer respect. Interestingly, these perceptions were uniform irrespective of student course performance.     

Survey results of the training, nutrition, and mental preparation of triathletes: practical implications of findings

Although triathlon is growing in popularity at a remarkable rate, it has not been extensively studied. The aims of this research were to identify preparation strategies used by triathletes and to categorize these strategies according to gender and consultation with triathlon coaches. Survey data collected from 401 triathletes (207 males, 194 females) revealed training, nutritional, and mental preparation habits. Most participants engaged in strength training, consumed food and/or fluids during and after training, set training and competition goals, and applied mental preparation strategies during training and the hour before racing. Water was the most commonly consumed fluid; positive self-talk was the most used mental strategy. Participants were more likely to consult with a triathlon coach than a nutrition or sport psychology professional. Athletes with more years of experience in triathlon and those competing in longer distances were more likely to consult a triathlon coach. Female triathletes were more likely than male triathletes to train with others, use mental preparation strategies, and report feeling anxious before competitions. More male triathletes reported using nutritional supplements during training than their female counterparts. These findings add to the limited research base on triathletes' training habits, and hopefully will help guide practitioners who work with this group. The results provide guidance for collaborative efforts among training, nutrition, and mental health professionals to best support triathletes.     

Concurrent validity of the Polar s3 Stride Sensor for measuring walking stride velocity

With this research, we sought to establish the accuracy of stride velocity data collected by the s3 Stride Sensor Participants walked along a GAITRite mat at self-selected slow, preferred, and fast velocities, with two s3 Stride Sensors attached to their right foot. The start position was systematically varied such that the GAITRite system would record the second through sixth strides at each walking velocity. Both slow and preferred walking velocities were underestimated by 14% relative to the GAITRite (p < .05), while independent of walking velocity, Strides 2 and 3 were underestimated by 26% and 9% (p < .05), respectively. Researchers should use caution when interpreting data collected at slow and preferred walking velocities and during the first three strides.     

信息传播媒体对农村小学生学习成绩的影响——以电视、电脑和手机为例

利用大规模随机抽样调查数据,分析了农村小学生看电视、用电脑和手机等信息传播媒体对他们学习成绩的影响,发现周间和周末使用这些传播媒体对学习成绩影响不同。看电视可以满足他们的娱乐和信息需求,周末适量地收看电视节目与他们的学习成绩之间呈现正相关关系;由于电脑和手机在农村小学生手中只充当游戏机的功能,使用这些媒体的时间与他们的学习成绩之间存在负相关关系,并且使用这些媒体的时间和对学习成绩的影响在男女生之间存在显著差异。