News endorser influence in social media

Social networking sites have become an online realm where users are exposed to news about current affairs. People mainly encounter news incidentally because they are re-distributed by users whom they befriended or follow on social media platforms. In my dissertation project, I draw on shared reality theory in order to examine the question of how the relationship to the news endorser, the person who shares news content, determines social influence on opinion formation about shared news. The shared reality theory posits that people strive to achieve socially shared beliefs about any object and topic because of the fundamental epistemic need to establish what is real. Social verification of beliefs in interpersonal communication renders uncertain and ambiguous individual perceptions as valid and objectively true. However, reliable social verification may be provided only by others who are regarded as epistemic authority, in other words as someone whose judgment one can trust. People assign epistemic authority particularly to socially close others, such as friends and family, or to members of their in-group. I inferred from this that people should be influenced by the view of a socially close news endorser when forming an opinion about shared news content but not by the view of a socially distant news endorser. In Study 1, a laboratory experiment (N = 226), I manipulated a female news endorsers social closeness by presenting her as an in-group or out-group member. Participants opinion and memory of a news article were not affected by the news endorsers opinion in either of the conditions. I concluded that the news article did not elicit motivation to strive for shared reality because participants were confident about their own judgment. Therefore, they did not rely on the news endorsers view when forming an opinion about the news topic. Moreover, the results revealed that participants had stronger trust in the news endorser when she expressed a positive (vs. negative) opinion about the news topic, while social closeness to the news endorser did not predict trust. On the one hand, this is in line with the social norm of sharing positive thoughts and experiences on social networking sites: adherence to the positivity norm results in more favorable social ratings. On the other hand, my findings indicate that participants generally had a positive opinion about the topic of the stimulus article and thus had more trust in news endorsers who expressed a similar opinion. In Study 2, an online experiment (N = 1, 116), I exposed participants to a news post by a relational close vs. relational distant news endorser by having them name a close or distant actual Facebook friend. There was a small influence of the news endorsers opinion on participants thought and opinion valence irrespective of whether the news endorser was a close or distant friend. The finding was surprising, particularly because participants reported stronger trust in the view of the close friend than in the view of a distant friend. I concluded that in light of an ambiguity eliciting news article, people may even rely on the views of less trustworthy news endorsers in order to establish a socially shared and, therefore, valid opinion about a news topic. Drawing on shared reality theory, I hypothesized that social influence on opinion formation is mediated by news endorser congruent responses to a news post. The results indicated a tendency for the proposed indirect relation however, the effect size was small and the sample in Study 2 was not large enough to provide the necessary statistical power to detect the mediation. In conclusion, the results of my empirical studies provide first insights regarding the conditions under which a single news endorser influences opinion formation about news shared on social networking sites. I found limited support for shared reality creation as underlying mechanism of such social influence. Thus, my work contributes to the understanding of social influence on news perception happening in social networking sites and proposes theoretical refinements to shared reality theory. I suggest that future research should focus on the role of social and affiliative motivation for social influences on opinion formation about news shared on social networking sites.Soziale Netzwerkseiten haben sich zu Orten entwickelt, an denen Nutzer:innen Nachrichten über aktuelle Ereignisse begegnen. Menschen treffen vor allem deswegen auf Nachrichten, weil diese von Personen geteilt werden, mit denen sie befreundet sind. In meiner Dissertation untersuche ich aufbauend auf der Shared Reality Theorie ob die Beziehung zu Nachrichten-Endorser:innen, also denjenigen, die Nachrichten teilen, bestimmt ob deren Ansichten einen Einfluss auf die Meinungsbildung haben. Die Shared Reality Theorie geht davon aus, dass Menschen ein fundamentales epistemisches Bedürfnis danach haben richtige und wahrhaftige Ansichten zu entwickeln. Deshalb streben sie nach Ansichten, die von anderen geteilt werden. Durch interpersonale Kommunikation verifizieren sie ihre Ansichten, wobei aus einer unsicheren und ambigen Wahrnehmung ein valides und objektives Urteil werden kann. Allerdings wird eine Wahrnehmung nur dann soziale verifiziert, wenn Menschen ihr Gegenüber als epistemische Autorität ansehen, also als jemanden, dessen Urteil sie vertrauen. Epistemische Autorität wird gewöhnlich Personen zugeschrieben, die einem nahestehen, z.B. Freunden oder Mitgliedern der eigenen In-Group. Daraus leite ich ab, dass die Meinungsbildung über Nachrichten, die auf sozialen Netzwerkseiten von einer sozial nahestehenden Person geteilt werden, von deren Ansicht beeinflusst sein sollte. Die Ansicht sozial entfernter Nutzer:innen sollte hingegen keinen Einfluss auf die Meinungsbildung haben. In Studie 1, einem Laborexperiment (N=226), manipulierte ich die soziale Nähe einer weiblichen Nachrichten-Endorserin, indem ich sie als In-Group oder Out-Group Mitglied vorstellte. In keiner der Bedingungen hatte die Meinung der Nachrichten-Endorserin einen Einfluss auf die Meinungen der Teilnehmenden über einen Nachrichtenartikel und auf ihre Erinnerung an dessen Inhalt. Daraus schließe ich, dass der Artikel keine Motivation für das Streben nach geteilter Realität ausgelöst hat, sondern die Teilnehmenden sich ihres eigenen Urteils sicher waren. Daher zogen sie die Ansicht der Nachrichten-Endorserin bei der Meinungsbildung nicht in Betracht. Darüber hinaus zeigen meine Ergebnisse, dass die Teilnehmenden dem Urteil der Nachrichten-Endorserin mehr vertrauten, wenn sie eine positive (vs. negative) Meinung über das Nachrichtenthema äußerte. Die soziale Nähe hingegen hatte keinen Effekt auf das Vertrauen in das Urteil der Nachrichten-Endorserin. Dies entspricht einerseits der auf sozialen Netzwerkseiten geltenden Norm, positive Gedanken und Erfahrungen zu teilen. Das Befolgen der Norm führt folglich zu einer positiveren sozialen Bewertung. Andererseits legen meine Ergebnisse nahe, dass die Teilnehmenden generell eine eher positive Meinung über das Thema des Artikels und folglich größeres Vertrauen in die Nachrichten-Endorserin hatten, wenn diese eine ähnliche Meinung äußerte. In Studie 2, einem Onlineexperiment (N=1.116), forderte ich die Teilnehmenden auf, einen nahestehenden oder entfernten Facebook-Freund zu nennen. Anschließend präsentierte ich ihnen einen fiktiven Nachrichten-Post mit einer Meinungsäußerung (positiv vs. negativ) des genannten Freundes/der genannten Freundin. Unabhängig von der sozialen Nähe der Nachrichten-Endorser:innen zeigte sich ein kleiner Einfluss ihrer Meinung auf die Valenz der Gedanken und Meinungen der Teilnehmenden über das Nachrichtenthema. Dieses Ergebnis war überraschend, insbesondere da die Teilnehmenden angaben, größeres Vertrauen in die Ansicht eines nahestehenden Freundes/einer nahestehende Freundin zu haben. Daraus schließe ich, dass sich Menschen angesichts eines ambigen Artikels sogar auf die Ansicht weniger vertrauenswürdiger Nachrichten-Endorser:innen verlassen, um sich eine sozial geteilte und damit valide Meinung über das Thema zu bilden. Zusammenfassend liefern die Ergebnisse meiner Studien erste Erkenntnisse über die Bedingungen, unter denen einzelne Nachrichten-Endorser:innen auf sozialen Netzwerkseiten die Meinungsbildung über Nachrichten beeinflussen. Die Ergebnisse sprechen nur teilweise dafür, dass das Streben nach geteilter Realität der zugrundeliegende Mechanismus dieses sozialen Einflusses ist. Meine Arbeit trägt somit einerseits zum Verständnis sozialer Einflüsse auf die Wahrnehmung von Nachrichten auf sozialen Netzwerkseiten bei. Anderseits zeigt sie Weiterentwicklungsbedarf der Shared Reality Theorie auf. Ich schlage vor, dass zukünftige Forschung insbesondere untersuchen sollte, welche Rolle soziale und affiliative Motive für soziale Einflüsse auf die Meinungsbildung über Nachrichten spielen, die auf sozialen Netzwerkseiten geteilt werden

Mapping Positive Change in Manitoba, Chihuahua, Mexico

While working in Manitoba Colony, Mexico, as teacher under Old Colony Mennonite Support from 2009 to 2014, I gathered data about the community from conversations and periodicals such as Kurze Nachrichten aus Mexico, Deutsch-Mexikanische Rundshau, Das Blatt, and Die Mennonitische Post. This information shows both changing demographics and positive growth that stems from improved literacy

Magnetic fields of opposite polarity in sunspot penumbrae

Context. A significant part of the penumbral magnetic field returns below the surface in the very deep photosphere. For lines in the visible, a large portion of this return field can only be detected indirectly by studying its imprints on strongly asymmetric and three-lobed Stokes V profiles. Infrared lines probe a narrow layer in the very deep photosphere, providing the possibility of directly measuring the orientation of magnetic fields close to the solar surface. Aims. We study the topology of the penumbral magnetic field in the lower photosphere, focusing on regions where it returns below the surface. Methods. We analyzed 71 spectropolarimetric datasets from Hinode and from the GREGOR infrared spectrograph. We inferred the quality and polarimetric accuracy of the infrared data after applying several reduction steps. Techniques of spectral inversion and forward synthesis were used to test the detection algorithm. We compared the morphology and the fractional penumbral area covered by reversed-polarity and three-lobed Stokes V profiles for sunspots at disk center. We determined the amount of reversed-polarity and three-lobed Stokes V profiles in visible and infrared data of sunspots at various heliocentric angles. From the results, we computed center-to-limb variation curves, which were interpreted in the context of existing penumbral models. Results. Observations in visible and near-infrared spectral lines yield a significant difference in the penumbral area covered by magnetic fields of opposite polarity. In the infrared, the number of reversed-polarity Stokes V profiles is smaller by a factor of two than in the visible. For three-lobed Stokes V profiles the numbers differ by up to an order of magnitude.Comment: 11 pages 10 figures plus appendix (2 pages 3 figures). Accepted as part of the A&A special issue on the GREGOR solar telescop

An international campaign of the 19th century to determine the solar parallax - The US Naval expedition to the southern hemisphere 1849 - 1852

In 1847 Christian Ludwig Gerling, Marburg (Germany), suggested the solar parallax to be determined by measuring the position of Venus close to its inferior conjunction, especially at the stationary points, from observatories on nearly the same meridian but widely differing in latitude. James M. Gilliss,astronomer at the newly founded U.S. Naval Observatory, enthusiastically adopted this idea and procured a grant for the young astronomical community of the United States for an expedition to Chile. There they were to observe several conjunctions of Venus and oppositions of Mars, while the accompanying measurements were to be taken at the US Naval Observatory in Washington D.C. and the Harvard College Observatory at Cambridge, USA. This expedition was supported by A. v. Humboldt, C.F. Gau{\ss}, J.F. Encke, S.C. Walker, A.D. Bache, B. Peirce and others. From 1849 to 1852 not only were astronomical, but also meteorological and magnetic observations and measurements recorded, mainly in Santa Lucia close to Santiago, Chile. By comparing these measurements with those taken simultaneously at other observatories around the world the solar parallax could be calculated, although incomplete data from the corresponding northern observatories threatened the project's success. In retrospect this expedition can be recognized as the foundation of the Chilean astronomy. The first director of the new National Astronomical Observatory of Chile was Dr. C.W. Moesta, a Hessian student of Christian Ludwig Gerling's. The exchange of data between German, American and other astronomers during this expedition was well mediated by J.G. Fl\"ugel, consul of the United States of America and representative of the Smithsonian Institution in Europe, who altogether played a major role in nurturing the relationship between the growing scientific community in the U.S. and the well established one in Europe at that time.Comment: 20 pages, 7 figure

Spiral-shaped wavefronts in a sunspot umbra

Solar active regions show a wide variety of oscillatory phenomena. The presence of the magnetic field leads to the appearance of several wave modes, whose behavior is determined by the sunspot thermal and magnetic structure. We aim to study the relation between the umbral and penumbral waves observed at the high photosphere and the magnetic field topology of the sunspot. Observations of the sunspot in active region NOAA 12662 obtained with the GREGOR telescope (Observatorio del Teide, Spain) were acquired on 2017 June 17. The data set includes a temporal series in the Fe I 5435 \AA\ line obtained with the imaging spectrograph GREGOR Fabry-P\'erot Interferometer (GFPI) and a spectropolarimetric raster map acquired with the GREGOR Infrared Spectrograph (GRIS) in the 10830 \AA\ spectral region. The Doppler velocity deduced from the restored Fe I 5435 \AA\ line has been determined, and the magnetic field vector of the sunspot has been inferred from spectropolarimetric inversions of the Ca I 10839 \AA\ and the Si I 10827 \AA\ lines. A two-armed spiral wavefront has been identified in the evolution of the two-dimensional velocity maps from the Fe I 5435 \AA\ line. The wavefronts initially move counterclockwise in the interior of the umbra, and develop into radially outward propagating running penumbral waves when they reach the umbra-penumbra boundary. The horizontal propagation of the wavefronts approximately follows the direction of the magnetic field, which shows changes in the magnetic twist with height and horizontal position. The spiral wavefronts are interpreted as the visual pattern of slow magnetoacoustic waves which propagate upward along magnetic field lines. Their apparent horizontal propagation is due to their sequential arrival to different horizontal positions at the formation height of the Fe I 5435 \AA\ line, as given by the inclination and orientation of the magnetic field.Comment: Accepted for publication in A&

Magnetic field topology of the RS CVn star II Pegasi

The dynamo processes in cool active stars generate complex magnetic fields responsible for prominent surface stellar activity and variability at different time scales. For a small number of cool stars magnetic field topologies were reconstructed from the time series of spectropolarimetric observations using the Zeeman Doppler imaging (ZDI) method. In this study we follow a long-term evolution of the magnetic field topology of the RS CVn binary star II Peg. We collected high-resolution circular polarisation observations of II Peg using the SOFIN spectropolarimeter at the Nordic Optical Telescope. These data cover 12 epochs spread over 7 years. A multi-line diagnostic technique in combination with a new ZDI code is applied to interpret these observations. Magnetic inversions using these data reveals evolving magnetic fields with typical local strengths of 0.5-1.0 kG and complex topologies. Despite using a self-consistent magnetic and temperature mapping technique, we do not find a clear correlation between magnetic and temperature features in the ZDI maps. Neither do we confirm the presence of persistent azimuthal field rings found in other RS CVn stars. Reconstruction of the magnetic field topology of II Peg reveals significant evolution of both the surface magnetic field structure and the extended magnetospheric field geometry. From 2004 to 2010 the total field energy drastically declined and the field became less axisymmetric. This also coincided with the transition from predominantly poloidal to mainly toroidal field topology. A qualitative comparison of the ZDI maps of II Peg with the prediction of dynamo theory suggests that the magnetic field in this star is produced mainly by the turbulent alpha^2 dynamo rather than the solar alphaOmega dynamo. Our results do not show a clear active longitude system, nor is there an evidence of the presence of an azimuthal dynamo wave.Comment: 20 pages, 10 figures; accepted for publication in Astronomy & Astrophysic