Zwischenraum – Eine Reise durch das Museum Insel Hombroich

Ohne Zusammenfassung     

Methodik, Sprachen und Grundlagen des Software Engineering

Ohne Zusammenfassung     

Kind und Jugendlicher in der Gemeinschaft Internationale Werktagung in Salzburg vom 31. Juli bis 4. August 1936

Ohne Zusammenfassung     

Erfassung von Schülerselbsteinschätzungen zum schulbezogenen Sozial- und Lernverhalten – Validierung der Schülereinschätzliste für Sozial- und Lernverhalten (SSL)

The Self-Report Checklist for Social and Learning Behaviour (SSL) is a student questionnaire comparable to the Teacher Report Checklist for Social and Learning Behaviour. The SSL assesses ten facets of social and learning behaviour using self-reports by students. The present study of 1267 students aged 9 to 19 years examines the factorial structure, psychometric properties and validity of this questionnaire. The reliabilities (Cronbach’s Alpha, retest) of all ten scales were sufficiently good and the postulated factorial structure was found in exploratory as well as in confirmatory factor analysis. Correlations of SSL-scales with scales of the Differencial Aggression Questionnaire and the Strengths and Difficulties Questionnaire as well as with grades in German and mathematics indicated mainly convergent and divergent validity. Furthermore, positive correlations were found to corresponding teacher ratings.     

Investigating the impact of observation errors on the statistical performance of network-based diffusion analysis

Experiments in captivity have provided evidence for social learning, but it remains challenging to demonstrate social learning in the wild. Recently, we developed network-based diffusion analysis (NBDA; 2009) as a new approach to inferring social learning from observational data. NBDA fits alternative models of asocial and social learning to the diffusion of a behavior through time, where the potential for social learning is related to a social network. Here, we investigate the performance of NBDA in relation to variation in group size, network heterogeneity, observer sampling errors, and duration of trait diffusion. We find that observation errors, when severe enough, can lead to increased Type I error rates in detecting social learning. However, elevated Type I error rates can be prevented by coding the observed times of trait acquisition into larger time units. Collectively, our results provide further guidance to applying NBDA and demonstrate that the method is more robust to sampling error than initially expected. Supplemental materials for this article may be downloaded from http://lb.psychonomic-journals.org/content/supplemental.     

A biomechanical comparison of countermovement performance after short-term traditional and daily-undulated loaded vertical jump training

In order to assess lower extremity muscle mechanical properties in athletes, power-load characteristics during multi-joint tasks are frequently examined. This work compared 6 weeks of traditional (TP) and daily-undulated (DUP) periodized loaded countermovement jumping (CMJ). 20 amateur athletes (age: 24.2 ± 2.6 years, height: 175.6 ± 7.1 cm, body mass: 71.5 ± 7.7 kg, 10 males/10 females) exercised three times weekly using maximal CMJs with loads corresponding to 0%, 15% and 30% of body mass. Prior to the training period, subjects were once-only assigned by random to either the TP or DUP training scheme. Pre-to-post training, maximal center of mass (COM) -height, -take-off velocity, -power output and -impulse were compared during CMJ with additional loads corresponding to 0–30% of body mass. ANOVA (time * group) with repeated measures revealed significant (P < 0.05) temporal gains of maximal COM-height (2–11%), -take-off velocity (1–7%), -power (2–8%) and -impulse (3–9%) over most loading conditions for TP and DUP. However, ANOVA indicated no group effects for any outcome. Independent from the periodization model, maximal power output remained statistically unchanged with increased testing loads. For short-term conditioning periods, TP and DUP were equally effective in enhancing biomechanical jumping variables under varying loading conditions.