Stichwort: Bildungsökonomie und Qualität der Schulbildung

Keyword: Education Economics and Quality of Schooling. With reference to an earlier keyword article from the same author, this contribution looks at recent developments in education economics. The focus is a critical review of the field‘s contribution to research on the necessary conditions for high quality schooling. Of particular interest at the moment are the institutional framework conditions in a school system, which set incentives for performance. These are judged to be better than resource-based strategies of quality assurance. The empirical basis is provided by estimates of production functions using data from international school performance studies. This article will point out the limited validity of evidence gained through these studies and the – in sum – contradictory empirical findings. For this reason, political recommendations on the basis of this approach should be more reserved.     

Lead soaps in paintings: Friends or foes?

The origin(s) and role(s) of metal soaps in paints are a worldwide concern today. These hybrid compounds, containing both fatty acid chains and metals associated with a carboxylate function, are increasingly identified in paints. As reviewed in the first part of this work, the presence of metal soaps in paints is differently interpreted in scientific publications: metal soaps are sometimes considered to play a positive role as anchor points, during paint drying processes; they can also be considered as responsible for many degradation processes (protrusions, efflorescences, darkening, etc.). Their origins are also interpreted in various ways. In some paintings (in particular from the twentieth century), they have sometimes introduced on purpose, as additives, to modify the physical properties of the painting materials. In older paintings, metal soaps are usually thought to result from an uncontrolled reaction of oil with lead-based pigments, in particular lead white, red lead, and lead tin yellow. In the second part of this work, the review of historical recipes of lead-based paint shows an important number of recipes based on controlled mixing of oil with lead driers. In the third part, the experimental reproduction of such traditional recipes using walnut oil and litharge (PbO) shows that lead soaps can be formed, both in about one hour at ～100°C, or in about one month at room temperature. It shows as well that after a few years, litharge is no longer detected in the paint medium, while different lead carbonates are. Finally, the micro-infrared spectroscopy and micro-X-ray diffraction re-analysis of protrusions from a nine-year model painting shows together with lead soaps, the presence of Pb₅(CO₃)₃(OH)₂O (‘synthetic plumbonacrite’), an unusual phase recently observed in a protrusion from a painting by Vincent Van Gogh. This work highlights (i) the multiple origins and roles of metal soaps in paints and (ii) the importance of combining the analysis of fragments from historical paintings with the analysis and reproduction of historical recipes. In particular, we show that the components detected today in historical paintings may severely differ from those originally used or prepared by the painter, complicating the assessment of the painter's intentions. More than the presence of metal soaps, the key questions to be tackled should be about their origins and (re)mobilization.     

FACILITATING THE DEVELOPMENT OF TALENTS

World class pioneering achievements are a nation's most valuable asset. They arise from the efforts of talents‐people of extraordinary ability. The vital task of fostering the emergence of such talents requires a concentrated effort covering the entire lifespan. Significant factors are parents, contemporaries and teachers as well as media, the societal atmosphere and contact with great social and scientific issues. These must act together to produce talents with not only the ability but also the dedication to achieve.

     

Effekte videobasierter Trainings zur Förderung der Selbstwirksamkeitsüberzeugungen über Klassenführung im Grundschulunterricht

Self-efficacy in classroom management and knowledge on classroom management are important teacher resources regarding their health. Fostering student teachers in their self-efficacy in classroom management and situated knowledge on classroom management is a promising approach for reducing reality shock at the beginning of in-service teaching. Thus, the present quasi-experimental pre-post control group study investigates whether video-based and practice-oriented coursework in teacher education can promote self-efficacy in classroom management and the professional vision of classroom management. Analyzing own classroom videos as well as analyzing videos from other teachers lead to a significantly higher latent increase in self-efficacy and professional vision than that of a control group. This was only the case for professional vision in a course with own teaching elements but without video analysis.