A Comparison of Label Switching Algorithms in the Context of Growth Mixture Models

Simulation studies involving mixture models inevitably aggregate parameter estimates and other output across numerous replications. A primary issue that arises in these methodological investigations is label switching. The current study compares several label switching corrections that are commonly used when dealing with mixture models. A growth mixture model is used in this simulation study, and the design crosses three manipulated variables—number of latent classes, latent class probabilities, and class separation, yielding a total of 18 conditions. Within each of these conditions, the accuracy of a priori identifiability constraints, a priori training of the algorithm, and four post hoc algorithms developed by Tueller et al.; Cho; Stephens; and Rodriguez and Walker are tested to determine their classification accuracy. Findings reveal that, of all a priori methods, training of the algorithm leads to the most accurate classification under all conditions. In a case where an a priori algorithm is not selected, Rodriguez and Walker’s algorithm is an excellent choice if interested specifically in aggregating class output without consideration as to whether the classes are accurately ordered. Using any of the post hoc algorithms tested yields improvement over baseline accuracy and is most effective under two-class models when class separation is high. This study found that if the class constraint algorithm was used a priori, it should be combined with a post hoc algorithm for accurate classification.     

Foot and ankle joint movements of dancers and non-dancers: a comparative study

Ballerinas use their ankle joints more extremely and sustain injuries on the ankle joint more frequently than non-dancers. Therefore, the ankle movement of dancers is important and should be studied to prevent injuries. Measuring ankle joint range of motion (ROM) using radiographs could demonstrate the contribution to motion of each joint. The aim of this study was to analyse and compare ankle joint movements and the ratio of each joint’s contribution during movement between dancers and non-dancers, using radiographic images. Dancers have lower dorsiflexion (26.7 ± 6.2°), higher plantarflexion (74.3 ± 7.1°) and higher total (101.1 ± 10.8°) ROMs than non-dancers (33.9 ± 7.0°, 57.2 ± 6.8° and 91.1 ± 9.3°, respectively) (p < 0.05). Although the ROMs were different between the two groups, the ratios of each joint movement were similar between these two groups, in all movements. Regarding total movement, the movement ratio of the talocrural joint was almost 70% and other joints accounted for almost 30% of the movement role in both dancers and non-dancers. Therefore, the differences in ROM between dancers and non-dancers were not a result of a specific joint movement but of all the relevant joints’ collaborative movement.     

Pre-service teachers’ motivation,sense of teaching efficacy,and expectation of reality shock

The present study investigated how pre-service teachers’ motivation and their sense of teaching efficacy influence their expectation about reality shock during the first year of professional teaching. A total of 533 pre-service teachers at a state university in the US Midwest participated in this study. The results showed that the pre-service teachers’ expectation of reality shock was negatively related to teacher efficacy and intrinsic motivation while it was positively related to introjected and external motivation. The results of a hierarchical regression analysis revealed that pre-service teachers’ sense of efficacy and introjected motivation were strong predictors of their expectation of reality shock, when gender difference was controlled for. There was an interaction effect between intrinsic motivation and teachers’ sense of efficacy in predicting the reality shock expectation. We discussed the educational implications for future research in an endeavour to reduce the reality shock among novice teachers.     

Introduction of Molecular Methods into a Food Microbiology Curriculum

Maintaining current, relevant curriculum in undergraduate Food Microbiology courses is essential for training future experts in food quality and safety. Having an understanding of the fundamental techniques (for example, polymerase chain reaction [PCR]) that are used in the food industry and regulatory agencies is critical for students entering the workforce. The purpose of this study was to assess the efficacy of integrating molecular methods into an undergraduate Food Microbiology course in both lecture and laboratory settings. Modules on PCR and pulsed‐field gel electrophoresis (PFGE), both of which are currently used by government agencies and the food industry to investigate the presence and persistence of foodborne pathogens, were developed, introduced, and evaluated among 269 students over 4 y. Multiple teaching and learning styles were incorporated through (i) traditional lecture format on the basics of PCR and PFGE; (ii) hands‐on group activities to build upon the lecture instruction; (iii) performing PCR and PFGE in the laboratory; and (iv) group discussions to analyze results from laboratory exercises. Pre‐ and postinstruction evaluations revealed significant increases in understanding and application of both methods in lecture and laboratory settings as demonstrated by 0.60 and 0.51 mean normalized gains for respective PCR and PFGE lectures and 0.50 and 0.56 mean normalized gains in respective labs. Academic year significantly impacted score improvement, potentially due to hidden factors, such as previous exposure to material and student aptitude. This study provides the platform for successful introduction of molecular techniques in an undergraduate Food Microbiology course. The guidelines and materials developed by our group are publicly available for use by other institutions.     

The duty to succeed: honor versus happiness in college and career choices of East Asian students in the United States

To better understand factors underlying educational and career choices, this study used both survey data from an online networking tool and data collected in college classrooms to gauge differences between Asians (primarily Korean) and white students in the United States. More Asians (41%) than whites (9%) prioritized prestige over happiness, while more white students (67%) than Asian‐American students (28%) deemed happiness as paramount in selecting a college. When assessing their parents, more Asian Americans thought their mothers (51%) and fathers (34%) emphasized prestige in choosing a college than white mothers (9%) and fathers (17%). In addition, Asian parents were assessed as much more prone to stress the importance of financial independence in career selection while white parents were perceived as prioritizing career enjoyment. Certain parenting techniques were much more common among Asians, such as reminding children of parental sacrifices made for the next generation, teaching them that academic performance is a matter of family honor and prodding academic success by comparing their accomplishments with those of children of family and friends. These findings may reflect a conscious strategy to overcome racial discrimination if education is seen as the primary path to upward social mobility. Awareness of the social and emotional cost of the staunch emphasis on the duty to succeed is important for those involved in educating and providing career counseling for college students with an Asian family background. Acknowledgement of pressure to honor parental expectations of narrowly defined acceptable academic and career achievement should be a part of counseling sessions that might otherwise focus exclusively on individual aspirations without due recognition of an interdependent, collectivistic orientation where upholding family expectations is integral to perceived success.