SOEP-IS 2014: Methodenbericht zur Zusatzerhebung Experience Sampling Methode (ESM)

Bei der Zusatzerhebung 'Experience Sampling Methode (ESM)' des SOEP Innovationssamples 2014 (SOEP-IS) handelte es sich um einen wichtigen Baustein eines Langzeitprojekts von Richard Lucas (Michigan State University) und dem SOEP Team am Deutschen Institut für Wirtschaftsforschung (DIW Berlin). Im Rahmen dieses Forschungsvorhabens soll die von Daniel Kahneman und Kollegen im Jahr 2004 vorgestellte Day Reconstruction Methode (DRM)1 zur Messung von subjektivem Wohlbefinden auf Lang- und Kurzzeitstabilität der erhobenen Messwerte, sowie im Vergleich zur etablierten Experience Sampling Methode (ESM) evaluiert werden. [...] Dieser Methodenbericht geht zunächst auf die Einzelheiten der Durchführung der Erhebung ein (Abschnitt 1). In Abschnitt 2 werden daraufhin die Erhebungsinstrumente skizziert. Zum Schluss beleuchtet Abschnitt 3 die Ergebnisse der Feldarbeit

Molecular and morphometric analysis of (semi-)cryptic species in Fragilariopsis kerguelensis

The diatom species Fragilariopsis kerguelensis is endemic to the Southern Ocean where it plays a key role in the ocean silica cycle due to its heavily silicified cell walls. Frustules from dead cells can sink to the ocean floor and therefore contribute about 90% to the diatom frustules making up the Antarctic opal belt, a band of heavily silicified sediments below the Antarctic Circumpolar Current. Recent studies showed that two morphotypes of F. kerguelensis can be found in core samples originating from the Southern Ocean. The morphotypes can be distinguished by the morphometric descriptor rectangularity and the abundance of the morphotypes can be linked to the origin of the samples from glacial or interglacial periods. It is, however, so far unknown whether these morphotypes also occur in current diatom assemblages of the Southern Ocean; if yes, how their occurrence is influenced by environmental conditions; and whether they represent different species, or rather phenotypic plasticity within a single species. For answering these questions diatom valves in water and sediment samples from the Southern Ocean, preserved on microscopic slides were analysed morphologically using a semi automated morphometry workflow. Histograms of the rectangularity were then plotted which all showed a bimodal distribution proving the existence of the two morphotypes in recent samples. In the next step the biogeographic distribution pattern of the two morphotypes was assessed by plotting the rectangularity distribution at each sample station. Whereas one morphotype was dominant in the northernmost samples, its dominance decreased towards the south, and the other morphotype became dominant in the southernmost locations investigated. This pattern could also be linked to the Sea Surface Temperature with a regression. After the previous findings the question arose if the morphotypes could be cryptic species or if they occur due to phenotypic plasticity within a single species. To answer this a genetic assessment with diatom strains showing different rectangularity values, isolated from the Southern Ocean and kept in live cultures at the Alfred-Wegener-Institut was done. Their ribosomal internal transcribed spacer (ITS) regions were amplified using PCR and then analysed with Sanger sequencing. The results made it possible to identify three potential species based on their genetic differences. One semi-cryptic species was solely made up of morphotype B whereas morphotype A was divided in two genetic clusters representing two cryptic species. Mating experiments were carried out to uncover possible reproductive barriers between the cryptic species. The results showed, that strains being assigned the same cryptic species commonly sexually reproduce, whereas sexual reproduction between strains from different cryptic species was only observed in a few exceptions. In summary, the two investigated morphotypes of Fragilariopsis kerguelensis can be found in the Southern Ocean today, with one dominating at higher, the other at lower Sea Surface Temperatures. Comparison of ribosomal ITS sequences and mating experiments indicate that the two morphotypes seem to belong to three different species, one semi-cryptic species belonging to one and two cryptic species to the other morphotype

Mobilfunknutzung in Deutschland: eine Herausforderung für die Stichprobenbildung in der Markt- und Sozialforschung

Der Autor geht der Frage nach, ob die Telefonstichproben der Markt- und Sozialforschung, die auf einem Auswahlmechanismus beruhen, welcher im Normalfall ausschließlich Festnetzrufnummern beinhaltet, im Jahre 2007 noch geeignet sind, qualitativ hochwertige Stichproben der Gesamtbevölkerung zu liefern. Denn die Zunahme der Mobilfunknutzung führt dazu, dass die Erreichbarkeit im Festnetz nicht mehr gegeben ist. Nicht nur die Anzahl derjenigen, die ausschließlich Mobilfunk nutzen, ist dabei von Interesse, sondern es kommt ein zweiter Aspekt hinzu: Gibt es systematische Unterschiede zwischen diesen beiden Subpopulationen und wenn ja, welche? Mit diesen beiden Fragekomplexen beschäftigt sich der erste Abschnitt des Beitrags anhand von Befragungsdaten aus dem TNS Infratest Face-to-Face-Omnibus. Im zweiten Abschnitt wird dargestellt, welche Lösungsansätze im Hinblick auf eine Integration der Mobilfunknummern in einen Auswahlrahmen für Telefonstichproben bislang verfolgt wurden. Abschließend werden einige weiterführende Aspekte diskutiert, die für die noch ausstehende Lösung des Mobilfunkproblems in Zukunft relevant sein könnten. (ICI2)"The article deals with the increasing use of mobile phones (cellular phones) in Germany with regard to the impact on probability sampling based on landline sample frames. Although the mobile penetration in the population is on a high density level the exclusive use of cell-phones and the abdication of fixed-line-telephones is quiet rare. Nevertheless the mobile-only-use has in some sub-populations reached a critical stage. In the last years research on methods of Market- und Social-Research have tried several ways of including mobile-phone-numbers in random telephone-samples. Currently a special form of random-last-digit approach, based on sophisticated reference lists not on the telephone-book, seems to be the most promising solution. Furthermore a coherent sample-design still needs to be developed in order to ensure efficient fieldwork and acceptable pricing. Last but not least the dynamic of the telecommunication sector should not be lost of track. On the one hand broadband internet connections will perhaps revitalise landline-phones. On the other hand new technical solutions will come up soon and will lead to further problems and possibilities for the future." (author's abstract