Pricing decisions in peer-to-peer and prosumer-centred electricity markets: Experimental analysis in Germany and the United Kingdom

Prosumer-centred electricity market models such as peer-to-peer communities can enable optimized supply and demand of locally generated electricity as well as an active participation of citizens in the energy transition. An important element of active participation is the improved ability of community members to identify and choose who they transact with in a much more granular way than is usual. Despite this key novelty and the social core of prosumer-centred markets, little is known about how citizens would trade with different actors involved in the system. This article reports a preregistered cross-national experiment investigating individual trading preferences in a peer-to-peer community with a variety of private and non-private trading actors. The data from the United Kingdom (n = 441) and Germany (n = 440) shows that set buying and selling prices strongly vary, pointing to three systematically different trading strategies that individuals apply as a function of involved trading actor. Findings moreover reveal that trading decisions are determined by individuals’ political orientation, place attachment, and climate change beliefs as well as individual differences in trust in the involved trading actor. Finally, the results illustrate high consistency in trading preferences across nations. However, nation-level differences emerged when decisions were made publicly visible, emphasising the need to consider context-effects in peer-to-peer system design. The findings have implications for the development of prosumer-centred energy models and the design of interventions to increase citizen participation across national contexts

From byproduct to design factor: on validating the interpretation of process indicators based on log data

International large-scale assessments such as PISA or PIAAC have started to provide public or scientific use files for log data; that is, events, event-related attributes and timestamps of test-takers’ interactions with the assessment system. Log data and the process indicators derived from it can be used for many purposes. However, the intended uses and interpretations of process indicators require validation, which here means a theoretical and/or empirical justification that inferences about (latent) attributes of the test-taker’s work process are valid. This article reviews and synthesizes measurement concepts from various areas, including the standard assessment paradigm, the continuous assessment approach, the evidence-centered design (ECD) framework, and test validation. Based on this synthesis, we address the questions of how to ensure the valid interpretation of process indicators by means of an evidence-centered design of the task situation, and how to empirically challenge the intended interpretation of process indicators by developing and implementing correlational and/or experimental validation strategies. For this purpose, we explicate the process of reasoning from log data to low-level features and process indicators as the outcome of evidence identification. In this process, contextualizing information from log data is essential in order to reduce interpretative ambiguities regarding the derived process indicators. Finally, we show that empirical validation strategies can be adapted from classical approaches investigating the nomothetic span and construct representation. Two worked examples illustrate possible validation strategies for the design phase of measurements and their empirical evaluation

Controlling speed in component skills of reading improves the explanation of reading comprehension

Efficiency in reading component skills is crucial for reading comprehension, as efficient subprocesses do not extensively consume limited cognitive resources, making them available for comprehension processes. Cognitive efficiency is typically measured with speeded tests of relatively easy items. Observed responses and response times indicate the latent variables of ability and speed. Interpreting only ability or speed as efficiency may be misleading because there is a within-person dependency between both variables (speed-ability tradeoff [SAT]). Therefore, the present study measures efficiency as ability conditional on speed by controlling speed experimentally with item-level time limits. The proposed timed ability measures of reading component skills are expected to have a clearer interpretation in terms of efficiency and to be better predictors for reading comprehension. To support this claim, this study investigates two component skills, visual word recognition and sentence-level semantic integration (sentence reading), to understand how differences in ability in a timed condition are related to differences in ability and speed in a traditional untimed condition. Moreover, untimed and timed reading component skill measures were used to explain reading comprehension. A German subsample from Programme for International Student Assessment (PISA) 2012 completed the reading component skills tasks with and without item-level time limits and PISA reading tasks. The results showed that timed ability is only moderately related to untimed ability. Furthermore, timed ability measures proved to be stronger predictors of sentence-level and text-level reading comprehension than the corresponding untimed ability and speed measures, although using untimed ability and speed jointly as predictors increased the amount of explained variance. (DIPF/Orig.

Invariance of the Response Processes Between Gender and Modes in an Assessment of Reading

In this paper, we developed a method to extract item-level response times from log data that are available in computer-based assessments (CBA) and paper-based assessments (PBA) with digital pens. Based on response times that were extracted using only time differences between responses, we used the bivariate generalized linear IRT model framework (B-GLIRT, [1]) to investigate response times as indicators for response processes. A parameterization that includes an interaction between the latent speed factor and the latent ability factor in the cross-relation function was found to fit the data best in CBA and PBA. Data were collected with a within-subject design in a national add-on study to PISA 2012 administering two clusters of PISA 2009 reading units. After investigating the invariance of the measurement models for ability and speed between boys and girls, we found the expected gender effect in reading ability to coincide with a gender effect in speed in CBA. Taking this result as indication for the validity of the time measures extracted from time differences between responses, we analyzed the PBA data and found the same gender effects for ability and speed. Analyzing PBA and CBA data together we identified the ability mode effect as the latent difference between reading measured in CBA and PBA. Similar to the gender effect the mode effect in ability was observed together with a difference in the latent speed between modes. However, while the relationship between speed and ability is identical for boys and girls we found hints for mode differences in the estimated parameters of the cross-relation function used in the B-GLIRT model

Automated and controlled processes in comprehending multiple documents

The study investigates automated and controlled cognitive processes that occur when university students read multiple documents (MDs). We examined data of 401 students dealing with two MD sets in a digital environment. Performance was assessed through several comprehension questions. Recorded log data gave indications about students\u27 time allocation, corroboration, and sourcing. Independent measures were used for reading speed to tap the effects of automatic processing and for working memory and single-text reading comprehension to tap effects of controlled processing, with working memory considered the mental capacity for performing controlled processing. We found that faster readers completed the MD tasks faster and showed more corroboration behavior. At the same time, students skilled in comprehension allocated more time to processing MD tasks and were more likely to show MD-specific behaviors of corroboration and sourcing. Students\u27 success in MD tasks was predicted by reading speed and working memory, with the effect of working memory being mediated by single-text comprehension. Behavioral indicators contributed independently in predicting students\u27 MD comprehension. Results suggest that reading MDs resembles a problem-solving situation where students need to engage in controlled, non-routine processing to build up a comprehensive representation of MDs and benefit from highly automated, lower-level reading processes. (DIPF/Orig.

Entwicklung und Skalierung eines Tests zur Erfassung des Verständnisses multipler Dokumente von Studierenden

Das Verständnis multipler Dokumente (Multiple Document Comprehension, MDC) wird als Fähigkeit verstanden, aus verschiedenen Informationsquellen eine integrierte Repräsentation eines inhaltlichen Gegenstandsbereichs zu konstruieren. Als solche ist sie sowohl für die erfolgreiche Bewältigung eines Studiums als auch für gesellschaftliche Partizipation eine wichtige Kompetenz. Bislang gibt es jedoch kein etabliertes Diagnostikum in diesem Bereich. Um diese Lücke zu schließen, wurde ein Test entwickelt, der vier zentrale kognitive Anforderungen von MDC abdeckt und auf Basis der Daten von 310 Studierenden sozial- und geisteswissenschaftlicher Fächer überprüft wurde. Die im MDC-Test gemessene Kompetenz erwies sich als eindimensional. Der MDC-Testwert wies theoriekonforme Zusammenhänge mit der Abiturnote, dem Studienabschnitt und der Leistung in einer Essay-Aufgabe auf. Insgesamt liefern die Ergebnisse empirische Belege dafür, dass der Testwert aus dem MDC-Test die fächerübergreifende Fähigkeit von Studierenden wiedergibt, multiple Dokumente zu verstehen. (DIPF/Orig.)Multiple document comprehension (MDC) is defined as the ability to construct an integrated representation based on different sources of information on a particular topic. It is an important competence for both the successful accomplishment of university studies and participation in societal discussions. Yet, there is no established assessment instrument for MDC. Therefore, we developed a test covering four theory-based cognitive requirements of MDC. Based on the data of 310 university students of social sciences and humanities, the MDC test proved to be a unidimensional measure. Furthermore, the test score was related to the final school exam grade, the study level (bachelor / master), and the performance in an essay task. The empirical results suggest that the score of the MDC test can be interpreted as the generic competence of university students to understand multiple documents. (DIPF/Orig.

Small-Scale Communities Are Sufficient for Cost- and Data-Efficient Peer-to-Peer Energy Sharing

Due to ever lower cost, investments in renewable electricity generation and storage have become more attractive to electricity consumers in recent years. At the same time, electricity generation and storage have become something to share or trade locally in energy communities or microgrid systems. In this context, peer-to-peer (P2P) sharing has gained attention, since it offers a way to optimize the cost-benefits from distributed resources, making them financially more attractive. However, it is not yet clear in which situations consumers do have interests to team up and how much cost is saved through cooperation in practical instances. While introducing realistic continuous decisions, through detailed analysis based on large-scale measured household data, we show that the financial benefit of cooperation does not require an accurate forecasting. Furthermore, we provide strong evidence, based on analysis of the same data, that even P2P networks with only 2--5 participants can reach a high fraction (96% in our study) of the potential gain, i.e., of the ideal offline (i.e., non-continuous) achievable gain. Maintaining such small communities results in much lower associated costs and better privacy, as each participant only needs to share its data with 1--4 other peers. These findings shed new light and motivate requirements for distributed, continuous and dynamic P2P matching algorithms for energy trading and sharing

Addressing climate change with behavioral science: a global intervention tournament in 63 countries

Effectively reducing climate change requires marked, global behavior change. However, it is unclear which strategies are most likely to motivate people to change their climate beliefs and behaviors. Here, we tested 11 expert-crowdsourced interventions on four climate mitigation outcomes: beliefs, policy support, information sharing intention, and an effortful tree-planting behavioral task. Across 59,440 participants from 63 countries, the interventions’ effectiveness was small, largely limited to nonclimate skeptics, and differed across outcomes: Beliefs were strengthened mostly by decreasing psychological distance (by 2.3%), policy support by writing a letter to a future-generation member (2.6%), information sharing by negative emotion induction (12.1%), and no intervention increased the more effortful behavior—several interventions even reduced tree planting. Last, the effects of each intervention differed depending on people’s initial climate beliefs. These findings suggest that the impact of behavioral climate interventions varies across audiences and target behaviors