Outlier detection by means of robust regression estimators for use in engineering science

This study compares the ability of different robust regression estimators to detect and classify outliers. Well-known estimators with high breakdown points were compared using simulated data. Mean success rates （MSR） were computed and used as comparison criteria. The results showed that the least median of squares （LMS） and least trimmed squares （LTS） were the most successful methods for data that included leverage points, masking and swamping effects or critical and concentrated outliers. We recommend using LMS and LTS as diagnostic tools to classify outliers, because they remain robust even when applied to models that are heavily contaminated or that have a complicated structure of outliers.     

Responsiveness of the anterior cruciate ligament – Return to Sports after Injury (ACL-RSI) and Injury – Psychological Readiness to Return to Sport (I-PRRS) scales

ABSTRACT

The ACL-Return to Sport after Injury (ACL-RSI) and Injury-Psychological Readiness to Return to Sport (I-PRRS) scales were developed to assess psychological factors associated with return to sports. Validity and reliability have been determined. The aim of this study was to investigate the responsiveness of the Dutch ACL-RSI and I-PRRS. Seventy patients with ACL reconstruction completed both scales twice 2 months apart, plus a Global Rating of Change (GRC) questionnaire. Distribution and logistic regression-based methods were used to study responsiveness. The Standardized Response Mean (SRM) for the ACL-RSI was 0.3 and for the I-PRRS 0.1, indicating low responsiveness. The minimally important change (MIC) for ACL-RSI was 2.6 and for the I-PRRS 0.9. Since the standard error of measurement (SEM) and smallest detectable change (SDC) were larger than MIC in individual patients, it does not seem possible to distinguish minimally important changes from measurement error in individual patients with either scale. At the group level responsiveness seemed sufficient; hence, both scales can be used to investigate the effectiveness of an intervention at the group level. Both scales can also be used in cross-sectional research and in clinical practice as screening instruments to identify patients at risk of not returning to sports.     

Response Timing Accuracy of Long-Distance Movements

Abstract

The purpose of the study was to compare the effectiveness of the Red Cross and Silvia methods of teaching beginning swimming. College women (N = 76), who were beginners in swimming, served as subjects. Pretests indicated no differences among the four classes prior to instruction. Reliability coefficients of the post-tests for distance and survival time (test-retest method) ranged from .70 to .98. ANOVA procedures utilizing front crawl distance, back crawl distance, survival time, and length of time required to pass the Red Cross combined tests as dependent variables resulted in superiority of the Silvia method over the Red Cross method in each analysis.     

Evaluation of the Physical Activity and Public Health Course for Practitioners

Purpose: From 1996 to 2013, a 6-day Physical Activity and Public Health Course for Practitioners has been offered yearly in the United States. An evaluation was conducted to assess the impact of the course on building public health capacity for physical activity and on shaping the physical activity and public health careers of fellows since taking the courses. Method: An evaluation quantified time that fellows spent in different course offerings and surveyed fellows. Results: From 1996 to 2012, 410 fellows attended the course, and in 2013, 186 participated in the Web-based survey (56% response rate). The number of fellows attending the course ranged from 15 to 33 yearly. From 1996 to 2012, the course averaged 38 hr of instructional time that included topics on interventions and environment/policy work to increase physical activity, program evaluation, public health research, and health disparities. The course included consultations, collaborative work, and field-based experiences. Fellows who participated in the survey agreed that the course had a positive impact on the physical activity research or practice work they did (98%), met their expectations (96%), helped them with research/practice collaborations with other physical activity professionals (96%), assisted them in conducting higher-quality interventions/programs (95%), helped increase their professional networking in the field (93%), and had a positive impact on other work they did (91%). Following the course, 66% and 56% had further contact with faculty and other fellows, respectively. Conclusion: The Physical Activity and Public Health Course for Practitioners made important contributions toward building the capacity of physical activity and public health practitioners.     

Knowledge sharing in open source software project teams: A transactive memory system perspective

The extant studies have not empirically examined the possible team cognitive mechanisms that facilitate knowledge sharing in OSS teams, even though knowledge sharing is a cognitive task and an OSS team is a complex cognitive system. To fill this research gap, we adopt the perspective of transactive memory system (TMS) to explore the relationships among TMS, knowledge sharing, communication quality, and technical achievement of OSS teams. By analyzing data from 95 OSS projects with the partial least squares (PLS) method, our study demonstrates that several TMS dimensions have positive impacts on knowledge sharing behaviors and communication quality. Moreover, communication quality positively influences technical achievement of OSS teams. These findings provide useful implications for literature and practice.     

Turning a City into a Milieu of Study: University Pedagogy as “Frontline”

In 2016 Bruno Latour delivered a lecture at Cornell University in which he responded to what he called the actual situation of disorientation and (literal) lack of common ground by offering some “hints for a neo‐Humboldtian university.” One hint he offered was that we should consider pedagogy as the frontline for staging an approach to societal challenges that links basic research and public engagement. Here, Jan Masschelein follows and extends upon this hint through exploring some ways to reclaim or reinvent the university as pedagogic form. Concretely, he describes the development of a course on designing educational practices that is conceived as a way to turn cities into a milieu of public and collective study. Masschelein's contribution to this symposium offers a “technical story” about physical, material experiences, one that contains some prepositions and propositions, an example, many detours, and a few practical notes and considerations. By this means, he explores the meaning and form pedagogy takes when we do not reduce it to teaching and extension, but instead approach it as the genus and the locus of a nexus between public engagement and basic research. Masschelein concludes by proposing the “public design studio” as a pedagogic form suited to the neo‐Humboldtian university.     

Repurposing children’s television for the classroom: teachers’ use of “square one tv” videocassettes

This study investigated whether a major new children’s television series on mathematics, produced primarily for an at-home audience, could be “repurposed” for classroom use. Segments were selected from the PBS children’s series, “Square One TV,” and edited into 30 videocassettes organized by curriculum topics. Teachers in two public elementary schools in Cambridge, Massachusetts, used the cassettes over a 10-week period. Both qualitative and quantitative data were collected, including teacher interviews, teacher journals of classroom use, researcher observations, a survey of student attitudes toward mathematics, and student interviews. Teachers found the reformatted cassettes to be useful motivational and instructional resources, especially in demonstrating connections between mathematical ideas and real-world situations. A videotape of teacher and student responses is available from the authors. This paper written while Dr. Chen was an assistant professor at the same school, won the Instructional Video Paper Competition marking the 25th anniversary of the Agency for Instructional Technology, Bloomington, Indiana.     

Der Übergang von der Grundschule in die Sekundarstufe I

Zusammenfassung Zu der Frage, auf welche Weise sich Merkmale der sozialen Herkunft auf den Schulübertritt nach der Primarstufe auswirken, wird in einer L?ngsschnittstichprobe 27 bayrischer Grundschulklassen der Verlauf des übertrittsprozesses untersucht, und zwar von den Bildungsaspirationen der Eltern am Ende der dritten Jahrgangsstufe über die Schullaufbahnempfehlungen der Lehrkr?fte bis hin zu den tats?chlichen Schulanmeldungen. Neben der Frage der Leistungsangemessenheit der Abschlussnoten und der erteilten Schulempfehlungen werden die Herkunftseffekte im Entscheidungsverlauf vertieft analysiert. Die letztendlich resultierende Schülerzuteilung zu den verschiedenen Bildungsg?ngen kovariiert deutlich mit der sozialen Herkunft der Schüler. Die vorgestellten Analysen der einzelnen vorgelagerten Entscheidungsschritte verweisen dabei auf eine st?rkere Bedeutung prim?rer gegenüber sekund?rer Einflusseffekte der sozialen Herkunft auf die Schulformzuteilung.