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Background Representational competence is commonly considered a prerequisite for the acquisition of conceptual knowledge, yet little exploration has been undertaken into the relation between these two constructs. Using an assessment instrument of representational competence with vector fields that functions without confounding topical context, we examined its relation with N = 515 undergraduates’ conceptual knowledge about electromagnetism. Results Applying latent variable modeling, we found that students’ representational competence and conceptual knowledge are related yet clearly distinguishable constructs (manifest correlation: r = .54; latent correlation: r = .71). The relation was weaker for female than for male students, which could not be explained by measurement differences between the two groups. There were several students with high representational competence and low conceptual knowledge, but only few students with low representational competence and high conceptual knowledge. Conclusions These results support the assumption that representational competence is a prerequisite, yet insufficient condition for the acquisition of conceptual knowledge. We provide suggestions for supporting learners in building representational competence, and particularly female learners in utilizing their representational competence to build conceptual knowledge., International Journal of STEM Education, 10 (1)

Science, technology, engineering, and mathematics (STEM) education in particular, uses different types of external representations, such as text, graphics, formula, visualizations, and more, for describing and explaining complicated topics and models (Rau, 2020). When different types of representation are combined with each other in the learning materials, this enables learning with multiple representations (MERs; Schüler, 2020). Theoretical approaches, such as the Cognitve Theory of Multimedia Learning (Mayer, 2014) and the Integrated Model of Text and Picture Comprehension (Schnotz & Bannert, 2003) suggest that MERs foster different learning processes and also problem solving. These assumptions are supported by empirical evidence (e.g., Eitel et al. 2013; Hu et al. 2021; Lee et al. 2006). Most empirical studies on the effect of MERs address heterogeneous combinations of representations (Lindner et al., 2016; Schüler et al., 2015) including analog (pictures, illustrations) and symbolic (text, formula) representations which form heterogeneous MERs (Malone et al., 2020). Less is known on the effect and processing of homogeneous MERs, which combine multiple analogous or multiple symbolic representations. In our previous research, we compared similarities and differences in university students' information processing between heterogeneous and homogeneous MERs in propositional logic tasks (Ott, Brünken, Vogel, & Malone, 2018), with the result that performance was better when homogeneous-symbolic MERs (text + formula) were used instead of single representations (text or formula). Moreover, homogeneous-symbolic MERs were as useful as functionally equivalent heterogeneous MERs (e.g., text + graphics). Eye-tracking analyses also showed that different types of MERs triggered different processing of information. In a subsequent study, we were able to replicate these results for the domain of solving linear systems of equations (Malone et al. 2020). The aim of the present study is a conceptual replication of the study by Ott et al. (2018), in which we will examine the extent to which these results are also evident for school children in grades 5 to 6. While university students are rarely but occasionally confronted with logical expressions and notation during their education, it can be assumed that these are completely unknown to the target group. We have therefore developed an age-appropriate computer-based multimedia learning program to teach basic propositional logic symbols and concepts. In addition, we developed an item set analogous to the items in Ott et al. (2018), which contains less complex logical expressions than the original tasks. Both were piloted in a preliminary study with 30 students.

Background An atrio-esophageal fistula is an exceedingly rare but devastating complication of atrial fibrillation (AF) ablation procedures. Delays to diagnosis and definitive treatment herald a poor prognosis, with the development of catastrophic neurological injury or death secondary to cerebral air emboli. A high level of suspicion is essential to improve recognition of this rare but devastating condition. Case Report A 59-year-old man presented to the emergency department with an acute stroke and reduced consciousness. This presentation was preceded by an uncomplicated AF ablation 19 days prior and a subsequent emergency department attendance within a few days of his procedure, where he had presented with a history of new chest pain and reflux symptoms. Imaging revealed intra-cranial and intra-cardiac air, which was attributed to an uncontrolled atrio-esophageal fistula. Treatment options were limited by the patient's clinical instability and the patient was eventually palliated after developing catastrophic brain injury due to extensive cerebral air emboli. Why Should an Emergency Physician Be Aware of This? Patients typically first present to the emergency department with new symptoms of either gastroesophageal reflux or chest pain, therefore, early recognition by emergency physicians is vital. Characteristic symptoms alongside a recent history of a cardiac ablation procedure should prompt additional diagnostic imaging to look for evidence of an atrio-esophageal fistula.

According to Grayson et al. , risk behavior in driving consists of hazard detection, threat appraisal, action selection and implementation. Hazard perception tests often include the task to react quickly to hazards within traffic scenarios. Thus, two components of risk behavior are included in one measure and therefore confounded: hazard detection and threat appraisal. Tracking the eye movements, researchers found evidence for novices having deficits regarding hazard detection . In contrast, Hystegge et al. revealed, that novice drivers were as fast as expert drivers in looking at still hazards but needed more time to evaluate them. The aim of the present eye tracking experiment was to investigate, whether experienced drivers outperform novices with regard to hazard detection or threat appraisal. 22 experienced drivers and 15 learner drivers were presented 32 animated traffic scenarios in a computer based hazard perception test. The depended variables were accuracy and speed of hazard detection (first fixation) and threat appraisal (reaction after detection). Experts outperformed novices clearly in hazard detection: They focused on more hazards and detected them faster than the novices. Moreover, after having detected a hazard, experts react to it more reliable but not faster than the novices.

Objective The aim of the current study was to compare the traditional, verbal, and motoric tasks regarding their contributions to hazard perception measurement. Background Traditional hazard perception tasks require the participants to respond to filmed traffic conflicts in an imprecise way, such as by pressing a button. More sophisticated tasks include either verbal specification or motoric localization of the perceived hazards. The present study investigated the participants’ gaze behavior when they were provided with an identical set of traffic animations but were instructed to perform one of three types of hazard perception tasks. Method In an eye tracking study, 69 drivers were shown animated traffic scenarios and instructed to perform the traditional (press button), verbal, or speeded motoric localization hazard perception task. Eye tracking revealed whether and when the participant had fixated a certain hazard cue. Results The participants in the traditional task group were slower to fixate emerging hazards, but quicker to respond to them than the participants of the verbal and the motoric groups. As a specific benefit, the verbal task differentiated between different types of failures. Conclusion Additional verbal or speeded motoric localization tasks seem to have increased the participants’ alertness when watching the animations. The verbal task provides valuable additional information regarding the participants’ performance. To approximate real-life hazard perception ability, it is recommended that researchers and practitioners use a combination of different hazard perception tasks for assessment and training.

Cognitive load theory is considered universally applicable to all kinds of learning scenarios. However, instead of a universal method for measuring cognitive load that suits different learning contexts or target groups, there is a great variety of assessment approaches. Particularly common are subjective rating scales, which even allow for measuring the three assumed types of cognitive load in a differentiated way. Although these scales have been proven to be effective for various learning tasks, they might not be an optimal fit for the learning demands of specific complex environments such as technology-enhanced STEM laboratory courses. The aim of this research was therefore to examine and compare the existing rating scales in terms of validity for this learning context and to identify options for adaptation, if necessary. For the present study, the two most common subjective rating scales that are known to differentiate between load types (the cognitive load scale by Leppink et al. and the naïve rating scale by Klepsch et al.) were slightly adapted to the context of learning through structured hands-on experimentation where elements such as measurement data, experimental setups, and experimental tasks affect knowledge acquisition. N = 95 engineering students performed six experiments examining basic electric circuits where they had to explore fundamental relationships between physical quantities based on the observed data. Immediately after the experimentation, the students answered both adapted scales. Various indicators of validity, which considered the scales’ internal structure and their relation to variables such as group allocation as participants were randomly assigned to two conditions with a contrasting spatial arrangement of the measurement data, were analyzed. For the given dataset, the intended three-factorial structure could not be confirmed, and most of the a priori-defined subscales showed insufficient internal consistency. A multitrait–multimethod analysis suggests convergent and discriminant evidence between the scales which could not be confirmed sufficiently. The two contrasted experimental conditions were expected to result in different ratings for the extraneous load, which was solely detected by one adapted scale. As a further step, two new scales were assembled based on the overall item pool and the given dataset. They revealed a three-factorial structure in accordance with the three types of load and seemed to be promising new tools, although their subscales for extraneous load still suffer from low reliability scores.

Representational competence is essential for the acquisition of conceptual understanding in physics. It enables the interpretation of diagrams, graphs, and mathematical equations, and relating these to one another as well as to observations and experimental outcomes. In this study, we present the initial validation of a newly developed cross-contextual assessment of students’ competence in representing vector-field plots and field lines, the most common visualization of the concept of vector fields. The Representational Competence of Fields Inventory (RCFI) consists of ten single choice items and two items that each contain three true or false questions. The tool can be easily implemented within an online assessment. It assesses the understanding of the conventions of interpreting field lines and vector-field plots, as well as the translation between these. The intended use of the tool is both to scale students’ representational competences in respect to representations of vector fields and to reveal related misconceptions (areas of difficulty). The tool was administered at three German-speaking universities in Switzerland and Germany to a total of 515 first- and third-semester students from science, technology, engineering, and mathematics subjects. In these first steps of the validation of the RCFI, we evaluated its psychometric quality via classical test theory in combination with Rasch scaling and examined its construct validity by conducting student interviews. The RCFI exhibits a good internal consistency of ω=0.86, and the results of the Rasch analysis revealed that the items discriminate well among students from lower to medium-high competence levels. The RCFI revealed several misunderstandings and shortcomings, such as the confusion of the conventions for representing field lines and vector-field plots. Moreover, it showed that many students believed that field lines must not exhibit a curvature, that the lengths of field lines matter, and that field lines may have sharp corners. In its current version, the RCFI allows assessing students’ competence to interpret field representations, a necessary prerequisite for learning the widespread concept of vector fields. We report on planned future adaptations of the tool, such as optimizing some of the current distractors., Physical Review Physics Education Research, 17 (2), ISSN:2469-9896

As multiple representations are common in math education, we examined different combinations of representations (text, formula, graphic) in the field of propositional logic. In two experiments, we investigated whether participants benefit from multiple representations, and whether the kind of representational combination affects performance. For the first experiment, 146 university students were divided into six groups: two single-representation groups (text or formula), three dual-representation groups (all possible pairs), and one triple-representation group. Results indicate that the combination of multiple symbolic representations (text + formula) was as helpful as combining analog and symbolic representations (text + graphic and text + formula + graphic): the participants provided with all such types of multiple representations outperformed all single representation groups. In a second experiment (N = 19, within-subjects) we compared the gaze behavior when working with multiple symbolic representations (text + formula) or combined symbolic and analog representations (text + graphic). The results demonstrate that text was the one representation that was attended most and can therefore be regarded as the reference representation in all useful combinations. Even though fewer gaze switches were observed between text and formulas than between text and graphics, performance (time on task and accuracy) did not differ. This research emphasizes the importance of various forms of multiple representations in mathematics learning and assessment, and sheds light on how different kinds of representations and their combinations are processed.

Empirical research has shown that augmented reality (AR) has the potential to promote learning in different contexts. In particular, this has been shown for AR-supported physics experiments, where virtual elements (e.g., measurement data) were integrated into the learners’ visual reality in real time: compared to traditional experimentation, AR reduced cognitive load and promoted conceptual learning. Drawing upon previous work from this column, we present an AR-supported experiment on simple electrical circuits that allows for real-time visualization including highlighting of electrical circuit schematics using either smartglasses or tablet computers. The experiment addresses students in introductory physics education and holds potential to provide visual assistance for complex electrical circuits in secondary or higher physics education.

The pedestrian intention is not only signalized by their past trajectory and head gaze direction, but by their whole body movement. In order to improve existing algorithms, analysis of pedestrian motions before entering a shared environment, like a street crossing, is necessary. In addition, more accurate human models are required for a digital reality in order to enable the scalable evaluation of autonomous systems using synthetic data, most of all in the area of autonomous driving. In this work, we present a first approach to capturing pedestrian locomotion in a field experiment using an existing motion capture solution. The motion of 20 participants in 80 crossing trials was recorded and numerically evaluated. The evaluation suggests, that the hip and shoulder rotation with respect to the street is more pronounced before crossing the street compared to other, non-critical behavior.

Hazard perception is one of the few quantifiable components of driving competency that can explain the high crash risk of novice drivers (see Horswill & McKenna, 2004). Some studies focused on investigating the stimulus part of hazard perception items by comparing several design features of the displayed traffic scenarios (e.g. Malone et al., 2012; Scialfa et al., 2013). Other empirical studies have been conducted to address the reaction part of hazard perception items (e.g. Vlakveld, 2014). Among others, existing hazard perception tests differ with respect to the ecological validity – the similarity to real-world demands – of the task that has to be completed by the participants (simple reaction, hazard localization, simulated driving, etc.). Based on the findings of general expertise research (see Glaser & Chi, 1988), the hypothesis of the present experiment was that an increased ecological validity of a hazard perception task has a positive effect on the magnitude of performance differences between more and less experienced drivers. 104 learner drivers and 51 experienced drivers were randomly assigned either to a less ecological valid version (multiple choice task) or a higher ecological valid version (reaction task) of a hazard perception test. In both conditions, the same 20 animated hazardous or non-hazardous traffic scenarios were presented. Overall, the experienced drivers outperformed the learner drivers. Principally, both of the applied versions of the test provided a criterion valid measure of driving expertise. However, increasing the ecological validity of the test by using a reaction task was especially beneficial for certain types of scenarios, leading to higher expertise-related differences. In addition, the reaction task provides response time measure as a further valid performance indicator. This allows the identification of those participants who are indeed able to detect a hazard in a certain scenario, but still have deficits in response time, compared to more experienced drivers. According to the present study, it is recommended to choose the reaction task over the multiple choice task to test hazard perception. Whether a further increase in ecological validity of the task would be useful, should be tested empirically in future research.

Computer und Laptops aber auch kleinere, leistungsstarke mobile Endgerate wie Mobiltelefone und Tablets werden haufig gewinnbringend zum Lernen genutzt. Vielversprechend erscheint daher auch der Einsatz solcher Technologien in der Diagnostik, auch wenn dieser bisher noch deutlich seltener erfolgt. Technologiegestutztes Assessment allgemein und Online Assessment im Speziellen weisen zahlreiche Vorteile gegenuber herkommlichen Verfahren auf. So konnen technologiebasierte Testverfahren zum einen okonomischer sein, zum anderen unterstutzen sie die Durchfuhrung spezieller Assessmentstrategien wie beispielsweise Adaptives Testen und Ambulantes Assessment und ermoglichen die Integration reichhaltigen Stimulusmaterials und lebensnaher Antwortformate. Die Verwendung von Informationstechnologien beim Assessment bringt aber auch Herausforderungen mit sich. So sind die entstehenden Kosten dem Nutzen kritisch gegenuber zu stellen. Insbesondere beim Online Assessment ist zudem zu uberprufen, inwieweit eine Kontrolle der Testsituation notwendig ist bzw. gewahrleistet werden kann.

Hazard perception – the driver's ability to identify road hazards – is one of the few measurable aspects of driving competency that can explain the high accident risk of some groups of drivers [1,2]. Hazard perception tests differ regarding several features. Only a few empirical studies have been conducted to systematically compare different design features of hazard perception tests as e.g. the presentation mode (static vs. dynamic) of the included traffic scenarios [3,4]. Beside the variation of the stimulus material, hazard perception tests differ regarding the kind of task that has to be fulfilled by the participants. In general, experts outperform novices more clearly with increasing ecological validity of a task – its similarity to the demands of a certain domain [5]. As an empirical indicator of validity is a clear difference between experts and novices, ecological valid tasks are expected to increases the quality of a test. The aim of the present study was to investigate whether the criterion validity of a hazard perception test can be enhanced by the application of an ecological valid task. 35 learner drivers and 31 experienced drivers were presented 21 animated driving scenarios that did or did not contain a potential hazard. One half of the participants were to react to hazards within the animation (high ecological validity) whereas the others worked on multiple-choice questions provided after the presentation (low ecological validity). The ANOVA revealed a main effect of expertise: experts scored highest. Moreover, a main effect of the task's ecological validity could be found: the multiple-choice task facilitated the test. No interaction between expertise and ecological validity could be found. The results indicate that both tasks lead to valid measures. Contrary to our expectations, the ecological validity of the task did not influence the criterion validity. Further research should be conducted e.g. in order to investigate, whether a further increase of ecological validity – e.g. by simulated driving – results in extended expert-novice differences.

In the present study, we applied the 4C/ID model to the hazard perception domain and investigated the effectiveness of two of its components. A computer-based learning environment with animated traffic scenarios and supportive and procedural information was developed. We employed a 2 by 2 factorial design with the between-subjects factors supportive and procedural information. The results indicate that the two information types seem to foster different components of hazard perception performance: either speed or accuracy.

Novice drivers have a high collision risk compared to more experienced drivers. The optimization of driving assessment's validity should lead to a better identification of those examinees that need further training before solo driving. The aim of the present two studies was to find out whether the integration of animated traffic scenarios can enhance some quality aspects of selected multiple choice items of the official German driving test. For the first study, we developed a static version of a set of multiple choice questions each containing a computerized still picture of a traffic scenario and a dynamic version that included animated instead of still pictures of the same situations. Driving novices (n=57) and experts (n=63) were presented 22 items either in the static or in the dynamic version. Only the novices benefited from the dynamic presentation. Fifty novices and 50 experts participated in a second longitudinal study including three measurements with parallel tests of the dynamic testing materials at intervals of three to four months. The novices, who were currently attending driving school, improved over time whereas the experts' performance remained stable. The results indicate that animation has positive effects on some quality aspects of driving assessment, but the problem of low criterion validity has to be addressed by the means of further approaches. Language: en

RCOG/NICE guidelines recommend that, for fetal compromise in labour, delivery should be accomplished ideally within 30 minutes. In this study, we investigated the factors which affect the decision-to-delivery (DD) intervals for emergency caesareans. To achieve this, prospective data were collected for all grade 1 and 2 caesareans performed on a busy labour ward over 12 months. We found that the ratio of labouring women to midwives had a significant effect on the DD intervals, which were significantly prolonged when 1 : 1 care was not provided ( 𝑃 < 0 . 0 0 1 ). The observed effect resulted exclusively from a prolonged transfer time to theatre. General anesthesia use shortened the DD interval for grade 1 caesareans ( 𝑃 < 0 . 0 0 1 ) and was more likely to be used during the day shift ( 𝑃 < 0 . 0 0 9 ). We conclude that midwifery staffing levels and the form of anaesthesia employed influence on DD intervals for the most urgent caesarean sections.

Our study examines the relationship between perceived discrimination and levels of C-reactive protein and blood pressure in low-income youth ages 10-15 years old.Data were collected from 10 to 15 year old focal children and their mothers. Face-to-face interviews were implemented to collect data on stressors including experiences of everyday discrimination from youth. High sensitivity CRP in dried blood spot samples and diastolic and systolic blood pressure were also collected at the time of the interview.Perceived discrimination among youth was significantly associated with higher levels of CRP, systolic, and diastolic blood pressure. CRP, systolic, and diastolic blood pressure remained significant after controlling for age-adjusted BMI, waist circumference, and other factors.Discrimination is a salient risk factor for inflammation and cardiovascular health. Early life course inflammation and cardiovascular reactivity are important candidate pathways through which the repeated exposure to discrimination for minority group members contributes to racial and economic health inequities in adulthood.

Laboratory mice serve as important models in biomedical research. Monitoring these animals for infections and infestations and excluding causative agents requires extensive resources. Despite advancements in detection and exclusion over the last several years, these activities remain challenging for many institutions. The infections and infestations present in laboratory mouse colonies are well documented, but their mode of introduction is not always known. One possibility is that wild rodents living near vivaria somehow transmit infections to and between the colonies. This study was undertaken to determine what infectious agents the wild mice on the University of Pennsylvania (Philadelphia) campus were carrying. Wild mice were trapped and evaluated for parasites, viruses, and selected bacteria by using histopathology, serology, and PCR-based assays. Results were compared with known infectious agents historically circulating in the vivaria housing mice on campus and were generally different. Although the ectoparasitic burdens found on the 2 populations were similar, the wild mice had a much lower incidence of endoparasites (most notably pinworms). The seroprevalence of some viral infections was also different, with a low prevalence of mouse hepatitis virus among wild mice. Wild mice had a high prevalence of murine cytomegalovirus, an agent now thought to be confined to wild mouse populations. Helicobacter DNA was amplified from more than 90% of the wild mice (59% positive for H. hepaticus). Given the results of this study, we conclude that wild mice likely are not a source of infection for many of the agents that are detected in laboratory mouse colonies at the University of Pennsylvania.