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With regard to current controversial public discussions about the credibility of scientific knowledge, it seems particularly important that students possess adequate ideas about the tentativeness of scientific knowledge, which is a key aspect of nature of science. However, international studies show that many pre-service science teachers tend to have naïve conceptions about the tentativeness and these conceptions turn out to be resistant to change. So far, no research was done, on the conceptions of German pre-service chemistry teachers about tentativeness. Therefore, two empirical, qualitative research studies were conducted. The first study with 50 participants was to investigate, which conceptions about tentativeness German pre-service chemistry teachers possess, what the origins of these conceptions are and if they are resistant to change. In a second study with 56 participants, it was examined how a more adequate and functional understanding could be promoted. Data were collected by using different methods, such as open-ended questionnaires and semi-structured interviews. The participants' views about tentativeness were assigned to different categories. Results show that most participants held inconsistent or only partially informed views on tentativeness. The views turn out to be resistant to change, and many participants are not able to explain their ideas. And if so, their explanations are mostly restricted to scientific theories. Additionally, dealing with tentativeness unsettles some participants. To promote an adequate understanding, new approaches were developed, like the BlackTube activity. Additionally, instructions should focus on the durability of scientific knowledge. Furthermore, a differentiated reflection on different types of scientific knowledge seems necessary.

We analyze stock price behavior around reconstitutions of the German DAX index family from 1990 to 2013. The strong price run-up of added stocks in the 2 months preceding the announcement date remains robust until 2 months after the effective date (ED), and is fully reversed 5 months later. Conversely, stock prices of deleted firms are under pressure until 10 months after the ED. Unlike most previous studies, we find that outright entries and exits have temporary price effects, as do additions to and deletions from better-known indices; however, promotions and demotions related to lesser-known indices command permanent stock price responses. Rather surprisingly, deleted stocks consistently earn higher abnormal returns than added stocks in the 5-year post-event period. Specifically, the return differential levels out at 77.3%. We establish that this differential in permanent stock prices is attributable to differences in operating performance and media coverage. In practice, index reconstitutions do not appear to give unambiguous signals about the long-run investment appeal of affected firms. However, index fund managers not constrained by tracking error minimization would be better off holding deleted stocks for 5 years after the ED. [ABSTRACT FROM AUTHOR]

Every country, particularly if it depends on foreign trade to such a high degree as the Federal Republic of Germany, has a vital interest in exploiting all its export opportunities. The authors have developed a measurement concept focusing on the foreign orientation of business managers. Their empirical research suggests that as many as one-third of the small- and medium-sized firms with a primarily domestic focus in their country could be turned into successful exporters. The paper not only reveals obstacles to exporting as perceived by the managers of these companies, but also points to specific measures to improve the efficiency of existing export promotion programs. [ABSTRACT FROM AUTHOR]