460 research outputs found
Dispositional and Situational Predictors of Coping with Expectation Violations: Experimental Studies on the ViolEx Model
Expectations are cognitions that are formed from past experiences, influence current behavior, and anticipate future events (Roese + Sherman, 2007). Thus, expectations should be accurate in order to effectively guide behavior (Panitz et al., 2021). However, some events cannot be predicted with certainty and predictions are therefore sometimes inaccurate. In particular, educational expectations are often over-optimistic and thus prone to expectation violations (Carolan, 2017). According to the ViolEx model, situation-specific expectations arise from general assumptions, such as the academic self-concept. If the outcome of a situation violates expectations, individuals may cope differently. Coping can trigger anticipatory responses such as assimilation (behavior is directed toward confirming expectations in the future), or it can lead to immunization (denial, devaluation, or ignoring expectation violations) or accommodation (expectation change/destabilization; Gollwitzer et al., 2018; Panitz et al., 2021). Whether expectations are maintained or changed depends strongly on the costs and benefits of each coping strategy, especially when accurate expectations are opposed to a positive self-concept. Both individual differences in personality and situational characteristics of expectation violation may affect coping (Panitz et al., 2021). With regard to individual differences, there is presumably a cross-situational tendency to respond to expectation violations with a particular coping pattern. Furthermore, individuals with a higher need for cognitive closure (NCC) should prefer unambiguous responses (Kruglanski + Webster, 1996). This leads to a bias in favor of existing knowledge and expectations and thus presumably to stronger expectation persistence despite discrepant evidence (Dijksterhuis et al., 1996). However, individuals with higher NCC should be strongly interested in avoiding future expectation violations, so coping tendencies are probably strongly related to situational characteristics such as the valence of expectation violation. Positive and negative valence of expectation violation previously led to outcomes similar to overoptimistic expectations in educational contexts: positive valence led to more accommodation (emergence of overoptimistic expectations) and negative valence led to more immunization (protection of academic self-concept and persistence of overoptimistic expectations; e.g., Garrett + Sharot, 2017). This optimistic bias may also influence how (un)controllable expectation violations are coped with, whereby higher controllability should lead to stronger assimilation and lower controllability to stronger immunization (Bhanji et al., 2016). Moreover, according to learning theories on the degree of expectation violations, expectations should be changed especially when the deviation from the expectation is particularly significant, whereas stronger immunization should follow when discrepancies are small (Rescorla + Wagner, 1972). The purpose of this dissertation is to extend knowledge about predictors and their interaction in coping with expectation violations in order to theoretically evaluate the ViolEx model and practically identify risk factors for dysfunctional coping with educational expectations. To this end, the first study included several dispositional and situational predictors, and N = 439 participants received standardized expectation-violating feedback in a word riddle. Our results support the assumption that dispositional preferences predict situational coping, but in addition, we found results contrary to learning theories on the degree of expectation violation, an optimistic bias only for negative valence, and strongly context-dependent effects of NCC, which predicted both assimilation and accommodation. Therefore, in the second study, we examined valence and NCC in more detail, and the results from N = 268 participants replicated and extended our previous findings: higher NCC again led to stronger accommodation and assimilation, but only for negative valence of expectation violation. Because our studies found biased coping only for negative valence but not for positive valence, we aimed to better understand the optimistic bias in the third study with case vignettes in N = 249 students by including controllability and self-enhancement. Negative valence leads to stronger assimilation when the expectation violation was controllable, and positive valence leads to stronger accommodation when individuals selfenhance. Our studies confirm that coping with expectation violations strongly depends on dispositional and situational characteristics. Our results show that the protection of academic self-concept and educational expectations is preferred over the accuracy of expectations across different situational circumstances. Thus, there is strong persistence in educational expectations despite disconfirming evidence. This might be adaptive as long as it does not lead to frequent expectation violations in the future and especially as long as the situation is controllable. But results differ for individuals with higher NCC, as they show both stronger assimilation and accommodation. The connection between the two strategies, which is often considered contrary, might have a different meaning in the educational context, representing an adaptive compromise between accurate expectations and a positive self-concept
Validation Studies of the ATLAS Pixel Detector Control System
The ATLAS pixel detector consists of 1744 identical silicon pixel modules
arranged in three barrel layers providing coverage for the central region, and
three disk layers on either side of the primary interaction point providing
coverage of the forward regions. Once deployed into the experiment, the
detector will employ optical data transfer, with the requisite powering being
provided by a complex system of commercial and custom-made power supplies.
However, during normal performance and production tests in the laboratory, only
single modules are operated and electrical readout is used. In addition,
standard laboratory power supplies are used. In contrast to these normal tests,
the data discussed here was obtained from a multi-module assembly which was
powered and read out using production items: the optical data path, the final
design power supply system using close to final services, and the Detector
Control System (DCS). To demonstrate the functionality of the pixel detector
system a stepwise transition was made from the normal laboratory readout and
power supply systems to the ones foreseen for the experiment, with validation
of the data obtained at each transition.Comment: 8 pages, 8 figures, proceedings for the Pixel2005 worksho
Class Attendance and Students’ Evaluations of Teaching: Do No-Shows Bias Course Ratings and Rankings?
Background: Many university departments use students’ evaluations of teaching (SET) to compare and rank courses. However, absenteeism from class is often nonrandom and, therefore, SET for different courses might not be comparable. Objective: The present study aims to answer two questions. Are SET positively biased due to absenteeism? Do procedures, which adjust for absenteeism, change course rankings? Research Design: The author discusses the problem from a missing data perspective and present empirical results from regression models to determine which factors are simultaneously associated with students’ class attendance and course ratings. In order to determine the extent of these biases, the author then corrects average ratings for students’ absenteeism and inspect changes in course rankings resulting from this adjustment. Subjects: The author analyzes SET data on the individual level. One or more course ratings are available for each student. Measures: Individual course ratings and absenteeism served as the key outcomes. Results: Absenteeism decreases with rising teaching quality. Furthermore, both factors are systematically related to student and course attributes. Weighting students’ ratings by actual absenteeism leads to mostly small changes in ranks, which follow a power law. Only a few, average courses are disproportionally influenced by the adjustment. Weighting by predicted absenteeism leads to very small changes in ranks. Again, average courses are more strongly affected than courses of very high or low in quality. Conclusions: No-shows bias course ratings and rankings. SET are more appropriate to identify high- and low-quality courses than to determine the exact ranks of average courses
Water repellency decreases with increasing carbonate content and pH for different biocrust types on sand dunes
Biocrusts are biological communities that occupy the soil surface, accumulate organic matter and mineral particles and hence strongly affect the properties of the soils they cover. Moreover, by affecting water repellency, biocrusts may cause a preferential infiltration of rainwater, with a high impact on the formation of local water pathways, especially for sand dunes. The aim of this study is to shed light on the connections between water repellency and pH, carbonate and organic matter content in two dune ecosystems with different biocrust types. For this, we used contact angle measurements, gas volumetric carbonate determination and organic matter characterization via FT-IR and TOF-SIMS. In both ecosystems, moss-dominated biocrusts showed higher water repellency and higher amounts of organic matter compared to algal or cyanobacterial biocrusts. Surprisingly, the biocrusts of the two dune systems did not show differences in organic matter composition or organic coatings of the mineral grains. Biocrusts on the more acidic dunes showed a significantly higher level of water repellency as compared to higher carbonate containing dunes. We conclude that the driving factor for the increase in water repellency between cyanobacterial and moss-dominated biocrusts within one study site is the content of organic matter. However, when comparing the different study sites, we found that higher amounts of carbonate reduced biocrust water repellency
Investigation of the Stability of the Poly(ethylene oxide) | LiNiCoMnO Interface in Solid‐State Batteries
While solid-state batteries (SSBs) comprising poly(ethylene oxide) (PEO) based electrolytes are successfully commercialized already for operation at elevated temperature, the selection of the cathode active material (CAM) has so far been limited to LiFePO. When using high-voltage CAMs such as LiNiCoMnO (NCM), the cells experience fast capacity fading – the cause of which is not consistently understood in literature. In this study, electrochemical impedance spectroscopy measurements in a three-electrode setup are applied to confirm that the NCM|PEO interface is indeed the Achilles\u27 heel in PEO-based SSBs at high voltages. In this regard, the interfacial stability on the cathode side depends not only on the upper cut-off voltage, but also on the molecular weight of PEO, strongly affecting the cell performance. Scanning electron microscopy images of the cathodes after cycling suggest that at high voltages interfacial degradation leads to fragmentation of the polymer backbone and to a decrease in viscosity of the solid polymer electrolyte. Overall, the results help to understand the detrimental processes occurring in PEO-based SSBs in combination with high-voltage cathodes
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