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Anthropomorphism, as a design feature of robots, is widely applied to enhance human-robot interaction in the social domain. Current knowledge of how anthropomorphism influences perception, attitudes, and actual behavior is gained via research with depicted and embodied robots. However, it remains unclear how comparable gained insights of both approaches are. Results of a current meta-analysis suggest that anthropomorphism positively influences subjective and objective measures in case of embodied robots, whereas in case of depicted robots predominantly effects on subjective measures seem to emerge. This follow-up analysis aims to further investigate this difference by using a recoded dataset including data of 41 studies, involving over 3,000 participants. The results illustrate that anthropomorphism investigated via embodied robots indeed facilitates both subjective and objective outcomes. Remarkably, studies concerning effects of anthropomorphism using depicted robots showed positive effects on a subjective level but failed to show any effects on an objective level. In conclusion, the results show that the consequences of anthropomorphism in human-robot interaction depend on how robots are presented to participants. Moreover, they reveal that the transfer of results gained via depicted robots to embodied human-robot interaction might lead to both overestimation on a subjective level and underestimation on an objective level regarding the consequences of anthropomorphism.

Tasks classically performed by human–human teams in today’s workplaces are increasingly given to human–technology teams instead. The role of technology is not only played by classic decision support systems (DSSs) but more and more by artificial intelligence (AI). Reliability is a key factor influencing trust in technology. Therefore, we investigated the reliability participants require in order to perceive the support agents (human, AI, and DSS) as “highly reliable.” We then examined how trust differed between these highly reliable agents. Whilst there is a range of research identifying trust as an important determinant in human–DSS interaction, the question is whether these findings are also applicable to the interaction between humans and AI. To study these issues, we conducted an experiment ( N = 300) with two different tasks, usually performed by dyadic teams (loan assignment and x-ray screening), from two different perspectives (i.e., working together or being evaluated by the agent). In contrast to our hypotheses, the required reliability if working together was equal regardless of the agent. Nevertheless, participants trusted the human more than an AI or DSS. They also required that AI be more reliable than a human when used to evaluate themselves, thus illustrating the importance of changing perspective.

Objective To understand the impact of time pressure and automated decision support systems (DSS) in a simulated medical visual search task. Background Time pressure usually impairs manual performance in visual search tasks, but DSS support might neutralize this negative effect. Moreover, understanding the impact of time pressure and DSS support seems relevant for many real-world applications of visual search. Method We used a visual search paradigm where participants had to search for target letters in a simulated medical image. Participants performed the task either manually or with support of a highly reliable DSS. Time pressure was varied within-subjects by either a trialwise time–pressure manipulation (Experiment 1) or a blockwise manipulation (Experiment 2). Performance was assessed based on signal detection measures. To further analyze visual search behavior, a mouse-over approach was used. Results In both experiments, results showed impaired sensitivity under high compared to low time pressure in the manual condition, but no negative effect of time pressure when working with a highly reliable DSS. Moreover, participants searched less under time pressure and when receiving DSS support, indicating participants followed the automation without thoroughly checking recommendations. However, the human-DSS team’s sensitivity was always worse than that of the DSS alone, independent of the strength of time pressure. Conclusion Negative effects of time pressure can be ameliorated when receiving support by a DSS, but joint overall performance remains below DSS-alone performance. Application Highly reliable DSS seem capable of ameliorating the negative impact of time pressure in complex detection tasks.

The present research revisits the old issue whether attitude information is best conveyed to pilots in a moving-horizon format or in a moving-aircraft format. Previous research has suggested that the moving-aircraft format might not be beneficial for flight path tracking but recoveries from unusual attitudes, although the result are not fully consistent. A limitation of studies to date is that the recovery task usually did not involve progressive attitude changes of the aircraft but only sudden discrete changes. Compared with a discrete stimulus, the continuous dynamics might increase the perceived time pressure to respond, which in turn can be expected to amplify the error proneness with a less intuitive format. Two experiments were conducted where flight novices and experienced pilots performed tracking and recover tasks with both formats. Recoveries were performed from both, sudden (discrete) and continuously developing attitude changes. Independent of whether novices or pilots were considered, the general superiority of the moving-aircraft format was confirmed. As expected, the benefits of this format became even more evident with progressive attitude changes. No differences were found for tracking. The results add to the evidence favoring the moving-aircraft over the moving-horizon format for both novices and pilots. The moving-aircraft format of the attitude indicator should at least be considered as a standard for new applications, such as ground control stations of unmanned aerial vehicles. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

Previous research has shown that individuals differ with respect to their preferred strategies in self-organized multitasking: They either prefer to work on one task for long sequences before switching to another (blocking), prefer to switch repeatedly after short sequences (switching), or prefer to respond almost simultaneously after processing the stimuli of two concurrently visible tasks (response grouping). In two experiments, we tested to what extent the choice of strategy and related differences in multitasking efficiency were affected by the between-resource competition (Wickens, 2002) of two tasks to be performed concurrently in a self-organized manner. All participants performed a set of dual tasks that differed with respect to the kind of stimuli (verbal vs. spatial) and/or responses (manual vs. vocal). The choice of strategy was hardly affected as most individuals persisted in their response strategy independent of the degree of resource competition. However, the efficiency of individuals preferring a switching or response-grouping strategy increased especially when the reduction in resource competition was response related (manual vs. vocal), leading even to considerable dual-tasking benefits under these circumstances. In contrast, individuals who preferred to block their responses did not achieve any considerable benefits (or costs) with either of the different dual tasks. (PsycInfo Database Record (c) 2020 APA, all rights reserved).

In multitasking research, a central question revolves around whether humans can process tasks in parallel. What “in parallel” refers to, however, differs between research perspectives and experimental approaches. From a task-level perspective, parallel processing can be conceived as to whether complete tasks are processed in an overlapping manner and how this impacts task performance. In contrast, a large body of literature solely focuses on the central stage of response-selection and whether it can run in parallel with other processing stages, an approach we refer to as the stage-level perspective. Importantly, although each perspective addresses related topics and highlights interindividual differences, they evolved through independent lines of research. In 2 experiments, we have taken a first step to investigate if individuals' tendencies for an overlapping versus serial processing mode on the task level are related to vulnerabilities for task interference on the stage level. Individual preferences for either task processing mode were assessed in the task switching with preview (TSWP) paradigm. Individuals’ vulnerability for task interference was assessed with the backward crosstalk effect (BCE) in a classical dual task. Our results suggest that individuals who prefer overlapping relative to serial task processing at the task level are less vulnerable to task interference during response selection, indicated by a smaller BCE. This difference, however, only emerged in the second experiment with an increased sample size and with task-stimuli that facilitate a bottom-up separation of tasks in the dual-task.

Objective The aim was to evaluate the relevance of the critique offered by Jamieson and Skraaning (2019) regarding the applicability of the lumberjack effect of human–automation interaction to complex real-world settings. Background The lumberjack effect, based upon a meta-analysis, identifies the consequences of a higher degree of automation—to improve performance and reduce workload—when automation functions as intended, but to degrade performance more, as mediated by a loss of situation awareness (SA) when automation fails. Jamieson and Skraaning provide data from a process control scenario that they assert contradicts the effect. Approach We analyzed key aspects of their simulation, measures, and results which we argue limit the strength of their conclusion that the lumberjack effect is not applicable to complex real-world systems. Results Our analysis revealed limits in their inappropriate choice of automation, the lack of a routine performance measure, support for the lumberjack effect that was actually provided by subjective measures of the operators, an inappropriate assessment of SA, and a possible limitation of statistical power. Conclusion We regard these limitations as reasons to temper the strong conclusions drawn by the authors, of no applicability of the lumberjack effect to complex environments. Their findings should be used as an impetus for conducting further research on human–automation interaction in these domains. Applications The collective findings of both Jamieson and Skraaning and our study are applicable to system designers and users in deciding upon the appropriate level of automation to deploy.

The application of anthropomorphic design features is widely believed to facilitate human–robot interaction. However, the preference for robots’ anthropomorphism is highly context sensitive, as different application domains induce different expectations towards robots. In this study the influence of application domain on the preferred degree of anthropomorphism is examined. Moreover, as anthropomorphic design can reinforce existing gender stereotypes of different work domains, gender associations were investigated. Therefore, participants received different context descriptions and subsequently selected and named one robot out of differently anthropomorphic robots in an online survey. The results indicate that lower degrees of anthropomorphism are preferred in the industrial domain and higher degrees of anthropomorphism in the social domain, whereas no clear preference was found in the service domain. Unexpectedly, mainly functional names were ascribed to the robots and if human names were chosen, male names were given more frequently than female names even in the social domain. The results support the assumption that the preferred degree of anthropomorphism depends on the context. Hence, the sociability of a domain might determine to what extent anthropomorphic design features are suitable. Furthermore, the results indicate that robots are overall associated more functional, than gendered (and if gendered then masculine). Therefore, the design features of robots should enhance functionalities, rather than specific gendered anthropomorphic attributes to avoid stereotypes and not further reinforce the association of masculinity and technology.

It has been recently suggested that research on human multitasking is best organized according to three research perspectives, which differ in their focus on cognitive structure, flexibility, and plasticity. Even though it is argued that the perspectives should be seen as complementary, there has not been a formal approach describing or explaining the intersections between the three perspectives. With this theoretical note, we would like to show that the explicit consideration of individual differences is one possible way to elaborate in more detail on how and why the perspectives complement each other. We will define structure, flexibility, and plasticity; describe what constitutes individual differences; will outline selected empirical examples; and raise possible future research questions helping to develop the research field. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

It is often assumed that if two people work on a failure-detection task one after the other, they will observe more failures than when only one person undertakes the task (4-eyes principle). However, human beings have also been found to exert less effort on tasks that they share responsibility for, a phenomenon called social loafing. In the current research, we assessed the effectiveness of sequential human redundancy in light of possible social loafing. In two laboratory experiments, teams of two participants performed a quality-control task in a blinded and in a nonblinded condition, operationally defined by whether or not evaluations of the first checker were forwarded to the second one. In the blinded condition, no social loafing was found, and a near-perfect overall team performance was observed. In contrast, nonblinded redundancy led to a substantial effort reduction of the second checker. However, despite this social-loafing effect at the second position, even nonblinded redundancy led to an overall safety advantage over a single-checker condition. Our research suggests that social loafing in sequential-human-redundancy work settings can occur but does not necessarily reduce the gains in overall reliability. Blinded processes, however, seem to provoke less social loafing than nonblinded processes. (PsycInfo Database Record (c) 2023 APA, all rights reserved)

This article describes a flight simulator study to validate a new command control system for longitudinal load factor $n_x$ . The system is called nxControl and actuates thrust, speedbrakes, and wheel brakes that directly influence the total energy state of the aircraft. It aims at manually flying with higher precision and lower workload. After a brief overview of the functionality of nxControl and its cockpit interfaces, the key results of earlier proof-of-concept simulator studies are summarized. The focus lies on the comprehensive flight simulator study with 24 airline pilots to conclusively evaluate the complete system. The task was a highly demanding approach trajectory containing segmented-continuous-descent in gusty wind conditions, touch-down, deceleration, and taxi as well as engine failure at low altitude. With nxControl, the pilots achieved higher precision in airspeed and energy control with lower workload compared to conventional manual thrust control. In addition, nxControl achieved safety benefits in case of an engine failure.

The application of anthropomorphic design features is widely assumed to facilitate human-robot interaction (HRI). However, a considerable number of study results point in the opposite direction. There is currently no comprehensive common ground on the circumstances under which anthropomorphism promotes interaction with robots. Our meta-analysis aims to close this gap. A total of 4856 abstracts were scanned. After an extensive evaluation, 78 studies involving around 6000 participants and 187 effect sizes were included in this meta-analysis. The majority of the studies addressed effects on perceptual aspects of robots. In addition, effects on attitudinal, affective, and behavioral aspects were also investigated. Overall, a medium positive effect size was found, indicating a beneficial effect of anthropomorphic design features on human-related outcomes. However, closer scrutiny of the lowest variable level revealed no positive effect for perceived safety, empathy, and task performance. Moreover, the analysis suggests that positive effects of anthropomorphism depend heavily on various moderators. For example, anthropomorphism was in contrast to other fields of application, constantly facilitating social HRI. The results of this analysis provide insights into how design features can be used to improve the quality of HRI. Moreover, they reveal areas in which more research is needed before any clear conclusions about the effects of anthropomorphic robot design can be drawn.

Technological advancements are ubiquitously supporting or even replacing humans in all areas of life, bringing the potential for human-technology symbiosis but also novel challenges. To address these challenges, we conducted three experiments in different task contexts ranging from loan assignment over X-Ray evaluation to process industry. Specifically, we investigated the impact of support agent (artificial intelligence, decision support system, or human) and failure experience (one vs. none) on trust-related aspects of human-agent interaction. This included not only the subjective evaluation of the respective agent in terms of trust, reliability, and responsibility, when working together, but also a change in perspective to the willingness to be assessed oneself by the agent. In contrast to a presumed technological superiority, we show a general advantage with regard to trust and responsibility of human support over both technical support systems (i.e., artificial intelligence and decision support system), regardless of task context from the collaborative perspective. This effect reversed to a preference for technical systems when switching the perspective to being assessed. These findings illustrate an imperfect automation schema from the perspective of the advice-taker and demonstrate the importance of perspective when working with or being assessed by machine intelligence.

Dieser Beitrag ist mit Zustimmung des Rechteinhabers aufgrund einer (DFG geförderten) Allianz- bzw. Nationallizenz frei zugänglich., This publication is with permission of the rights owner freely accessible due to an Alliance licence and a national licence (funded by the DFG, German Research Foundation) respectively

Objective The study addresses the impact of time pressure on human interactions with automated decision support systems (DSSs) and related performance consequences. Background When humans interact with DSSs, this often results in worse performance than could be expected from the automation alone. Previous research has suggested that time pressure might make a difference by leading humans to rely more on a DSS. Method In two laboratory experiments, participants performed a luggage screening task either manually, supported by a highly reliable DSS, or by a low reliable DSS. Time provided for inspecting the X-rays was 4.5 s versus 9 s varied within-subjects as the time pressure manipulation. Participants in the automation conditions were either shown the automation’s advice prior (Experiment 1) or following (Experiment 2) their own inspection, before they made their final decision. Results In Experiment 1, time pressure compromised performance independent of whether the task was performed manually or with automation support. In Experiment 2, the negative impact of time pressure was only found in the manual but not in the two automation conditions. However, neither experiment revealed any positive impact of time pressure on overall performance, and the joint performance of human and automation was mostly worse than the performance of the automation alone. Conclusion Time pressure compromises the quality of decision-making. Providing a DSS can reduce this effect, but only if the automation’s advice follows the assessment of the human. Application The study provides suggestions for the effective implementation of DSSs in addition to supporting concerns that highly reliable DSSs are not used optimally by human operators.

Recent investigation of individual differences in multitasking revealed evidence for individual preferences for modes of task processing (serial vs. overlapping) in a task switching with preview (TSWP) paradigm and different strategies of response organization (blocking, switching, and response grouping) in a free concurrent dual-tasking (FCDT) paradigm. However, this research on individual differences at the levels of cognitive task processing and behavioral response organization has been pursued separately, thus far, by testing independent samples of participants. In the current study, we investigated whether these two levels of task coordination were linked intra-individually. As individuals preferring an overlapping task processing mode can generate time gains particularly at task switches, we predicted that they prefer a switching strategy of response organization. In contrast, individuals preferring a serial processing mode are expected to prefer a blocking strategy to reduce dual-task demands. These predictions were confirmed in an experiment based on n = 70 participants. Indeed, most serial processors preferred a blocking strategy, whereas overlapping processors predominantly preferred to switch between the tasks. This finding suggests a strong correspondence between individual preferences emerging in both aspects of task coordination, which might reflect a common basic difference in the preferred style of cognitive control (flexible vs. persistent). Moreover, in case the preferred modes of task processing and strategies of response organization did not correspond to each other, the overall multitasking efficiency was comparably low. Thus, the distinction between the preferences for both aspects of multitasking seems to be an important aspect of understanding multitasking performance and should be considered in future studies.

Abstract. In order to enable pilots to better maintain energy awareness and energy management in manual flight, a new concept has been proposed, which transfers the demand control principle of fly-by-wire control laws also to the control of thrust. It includes a total-energy-related augmented thrust controller combined with a modified cockpit instrumentation enriched by specific energy displays. In order to empirically evaluate the human performance consequences of this new approach, an experimental study was conducted in a flight simulator investigating its effects on pilots’ performance, workload, and situation awareness. A total of 24 commercial aircraft pilots performed a landing and approach on a complex flight trajectory with and without the new system elements. The results confirm the expected beneficial effects of the new system on flight precision and lowered effort involved in thrust control as compared with conventional raw data flying. No negative side effects, for example, impaired situation awareness, were found.

Abstract. A simulator study investigated the consequences of a transition between two alternative formats of the attitude indictor in aircraft cockpits, the moving-horizon and moving-aircraft format. Two groups of novices practiced performing two flight tasks (flight-path tracking and recovery from unusual attitudes) with one attitude-indicator format for six practice sessions, before transitioning to the other format. The results show that, after practice, participants were able to perform both tasks equally well with both attitude-indicator formats. However, the number of reversal errors in the recovery task increased considerably when transitioning from the moving-aircraft to moving-horizon format. No such effect emerged for the other direction. This suggests that the former transition is more difficult and represents a possible risk for flight safety.

This chapter particularly focuses on the performance consequences of decision support systems (DSSs) with a particular emphasis on the issue of automation bias as demonstrated in research across many domains. We examine the factors that impact automation bias including operator characteristics such as trust in the system, level of perceived accountability, system characteristics such as reliability, transparency, and understandability, the level and degree of automation involved, and the characteristics of the task-context including time pressure, consequences of errors, workload, or working in redundant work teams. We also discuss the challenge of balancing the pros and cons of using automation as a heuristic in decision making as well as current trends and future advances in automated system.

Dieser Beitrag ist mit Zustimmung des Rechteinhabers aufgrund einer (DFG geförderten) Allianz- bzw. Nationallizenz frei zugänglich., This publication is with permission of the rights owner freely accessible due to an Alliance licence and a national licence (funded by the DFG, German Research Foundation) respectively., Objective: This research investigates the potential behavioral and performance benefits of a 4-stage likelihood alarm system (4-LAS) contrasting a 3-LAS, a binary alarm system with a liberal threshold (lib-BAS) and a BAS with a conservative threshold (con-BAS). Background: Prior research has shown performance benefits of 3-LASs over conventional lib-BASs due to more distinct response strategies and better discriminating true from false alerts. This effect might be further enhanced using 4-LASs. However, the increase of stages could cause users to reduce cognitive complexity by responding in the same way to the two lower and the two higher stages, thus treating the 4-LAS like a con-BAS. Method: All systems were compared using a dual task paradigm. Response strategies, number of joint human machine (JHM) false alarms (FAs), misses, and sensitivity were regarded. Results: Compared to the lib-BAS, JHM sensitivity only improved with the 4-LAS and the con-BAS. However, the number of JHM misses was lowest for the con-BAS compared to all other systems. Conclusion: JHM sensitivity improvements can be achieved by using a 4-LAS, as well as a con-BAS. However, only the latter one may also reduce the number of JHM misses, which is remarkable considering that BASs with conservative thresholds a priori commit more inbuilt misses than other systems.

Objective: The experiments investigated the “old issue” of the attitude indicator’s moving-horizon versus moving-aircraft format with current primary flight display technology. Of interest was whether the effects found in earlier studies, favoring the moving-aircraft format, could be replicated with most recent technology including extended horizon displays, which depict the artificial horizon extended over the whole screen with overlaying speed and altitude scales (e.g., B787). Background: Although the moving-horizon format represents the standard approach in Western aviation, human factors research from the 1950s to the 1970s with round electromechanical instruments favored the moving-aircraft format with respect to better support of flight-path tracking and unusual attitude recoveries. However, recent studies using laboratory displays more similar to modern primary flight displays provided inconsistent results. This led to the assumption that the display’s design is a moderating factor of those effects. Method: Thirty-two novices and 13 pilots flew several tracking and recovery tasks in a PC-based simulator equipped with moving-horizon and moving-aircraft formats in classic and extended horizon design. Results: The data show that the previous effects favoring a moving-aircraft format of displaying bank information can be replicated with current primary flight display designs. However, the extended horizon design seems to reduce this effect, at least for pilots. Conclusion: The results suggest reconsidering the format of the attitude indicator at least for new applications, such as control of remotely piloted aircraft.

More complex flight trajectories and rising requirements on flight precision increase pilots’ workload during manual flight. The control augmentation system nxControl supports manual control by enabling pilots to command the longitudinal load factor \(n_x\) instead of engine thrust and spoiler deflections in flight. The load factor \(n_x\) is equivalent to the total energy angle and is directly influenced by thrust and aerodynamic drag. The system allows for higher precision with lower workload during manual flight. In order to prevent mode switching problems in the time-critical and demanding situations of take-off and landing the system was extended with a ground mode for aircraft control on ground and the transition phases. It controls forward thrust, spoilers, wheel brakes, and thrust reverser. This paper describes the design of the feedback controller considering common take-off and landing procedures as well as the pilots’ view. The resulting control laws of the ground mode as well as the new human-machine interface are presented. In a flight simulator study with seven airline pilots, the feasibility of the nxControl extension was tested in landing, taxi, and take-off scenarios. The results show, that the pilots were able to precisely manage the used runway length at landing. At taxi, the pilots could manage taxi speed with low command input frequency. The general performance during the take-off process, in particular in case of engine failure, was not influenced by nxControl.

A command system for manual control of the longitudinal load factor in flight path direction of an aircraft is designed that completes existing flight control command systems (e.g. with sidesticks that command normal load factor). The system is called nxControl. It aims to assist pilots during manual flight by reducing the workload for monitoring flight parameters as well as for controlling thrust and airbrakes. Important for the nxControl concept is the direct flight mechanical relation between longitudinal load factor and changes of the total aircraft energy. This paper presents the system concept and a prototype realization. The nxControl system consists of the control law that combines the actuation commands for engines and airbrakes, a new input device for the longitudinal load factor command and augmented display elements informing pilots about aircraft energy states to assure situation awareness. In order to investigate the feasibility of the concept as well as to evaluate consequences on human performance, a flight simulator study with airline pilots was conducted. The nxControl prototype was used by the pilots as expected. Changes in instrument scanning behaviour and thrust lever usage confirmed this. After just a short familiarization and practice, the pilots were able to perform standard flight tasks with nxControl without exceeding given tolerance limits. So, the results provide first evidence for the feasibility of the concept.

Dieser Beitrag ist mit Zustimmung des Rechteinhabers aufgrund einer (DFG geförderten) Allianz- bzw. Nationallizenz frei zugänglich., This publication is with permission of the rights owner freely accessible due to an Alliance licence and a national licence (funded by the DFG, German Research Foundation) respectively., It is safety critical for pilots to be aware of the aircraft’s energy state in terms of proper altitude and airspeed. A loss of energy awareness is an important human factors issue in modern civil aircraft. In order to maintain the energy awareness and support the manual flying skills, several cockpit display concepts suggest to augment the current energy status of the aircraft on primary flight displays in terms of the total energy angle. An experiment was carried out to determine which effect this additional energy information has on pilots’ flight path control, instrument scanning, and situation awareness. Outcomes of the study show a significant shift of the scanning pattern from airspeed, altitude scale, and engine parameter towards the center of the primary flight display with unchanged situation awareness. In addition, pilots are better able to maintain given speed targets.

The prevalence and the efficiency of serial and parallel processing under multiple task demands are highly debated. In the present study, we investigated whether individual preferences for serial or overlapping (parallel) processing represent a permanent predisposition or depend on the risk of crosstalk between tasks. Two groups (n = 91) of participants were tested. One group performed a classical task switching paradigm, enforcing a strict serial processing of tasks. The second group of participants performed the same tasks in a task-switching-with-preview paradigm, recently introduced by Reissland and Manzey (2016), which in principle allows for overlapping processing of both tasks in order to compensate for switch costs. In one condition, the tasks included univalent task stimuli, whereas in the other bivalent stimuli were used, increasing risk of crosstalk and task confusion in case of overlapping processing. The general distinction of voluntarily occurring preferences for serial or overlapping processing when performing task switching with preview could be confirmed. Tracking possible processing mode adjustments between low- and high-crosstalk conditions showed that individuals identified as serial processors in the low-crosstalk condition persisted in their processing mode. In contrast, overlapping processors split up in a majority adjusting to a serial processing mode and a minority persisting in overlapping processing, when working with bivalent stimuli. Thus, the voluntarily occurring preferences for serial or overlapping processing seem to depend at least partially on the risk of crosstalk between tasks. Strikingly, in both crosstalk conditions the individual performance efficiency was the higher, the more they processed in parallel.

This article describes the development, application and validation of a safety culture assessment approach for nuclear power plants based on Schein's culture model. The developed multi-method approach aimed to unfold deeper levels of culture, and, at the same time, to be applicable by practitioners and transparent in producing meaningful results. In Study 1 we describe the development of the method and its application in a German nuclear power plant. Study 2 presents a crossvalidation of the approach in a second German nuclear power plant. The evaluation results of the approach reveal adequate validity with regard to the obtained results and its perceived congruence to safety culture in both plants. It becomes evident that the approach allows for deriving basic assumptions of plant members and demonstrating their significance for safety performance. Moreover, it can be shown that it is worthwhile to go beyond the assessment of artifacts and espoused values in understanding cultural dynamics on a plant level. Finally, insights and limitations of the developed approach are discussed and reflected.

With rising demands on flight precision and more complex flight trajectories, pilots' workload during manual flight is increasing. This is especially the case for thrust and spoiler control during approach and landing. The presented nxControl system enables pilots to manually control the longitudinal load factor nx instead of engine parameters and spoiler deflections. This load factor is equivalent to total energy angle and is directly influenced by engine thrust and aerodynamic drag. The nxController complements existing control augmentation systems such as the fly-by-wire control laws of today's commercial airliners. It aims at higher precision with lower workload during manual flight. The controller input can be set and monitored by an adapted human-machine interface consisting of a thrust-lever-like inceptor and additional display elements to enhance energy awareness. This paper presents the nxControl system with focus on the command control system and an evaluation study with 24 airline pilots in a research flight simulator. The task was a demanding and steep approach with required navigation performance RNP 0.1 in a mountainous area. The results show higher precision and lower workload with the nxControl system despite minimal amount of training.

During space flight, astronauts are exposed to a variety of stressors. Some of these stressors originate from the specific environmental conditions in space (e.g. microgravity, radiation). Others are more unspecific and originate from living and working as member of a small crew in a confined and isolated habitat (e.g. lack of privacy, social monotony). This chapter summarizes our current knowledge about the impact of these space flight-related stressors on cognitive and psychomotor performance of astronauts. It suggests that basic cognitive processes are highly resilient and remain as efficient in space as on Earth. Similarly also processes of spatial imagery and object recognition do not seem to be affected much by the altered conditions in space. In contrast, considerable performance decrements have consistently been observed in different psychomotor tasks. These decrements seem to be caused by microgravity-induced changes of sensorimotor processes, at least during a transient period of primary adaptation to space. The available evidence pointing to impairments of executive functions and higher cognitive processes in space is less conclusive at this time.

Image-guided navigation (IGN) systems provide automation support of intra-operative information analysis and decision-making for surgeons. Previous research showed that navigated-control (NC) systems which represent high levels of decision-support and directly intervene in surgeons' workflow provide benefits with respect to patient safety and surgeons' physiological stress but also involve several cost effects (e.g. prolonged surgery duration, reduced secondary-task performance). It was hypothesised that less automated distance-control (DC) systems would provide a better solution in terms of human performance consequences. N = 18 surgeons performed a simulated mastoidectomy with NC, DC and without IGN assistance. Effects on surgical performance, physiological effort, workload and situation awareness (SA) were compared. As expected, DC technology had the same benefits as the NC system but also led to less unwanted side effects on surgery duration, subjective workload and SA. This suggests that IGN systems just providing information analysis support are overall more beneficial than higher automated decision-support.This study investigates human performance consequences of different concepts of IGN support for surgeons. Less automated DC systems turned out to provide advantages for patient safety and surgeons' stress similar to higher automated NC systems with, at the same time, reduced negative consequences on surgery time and subjective workload.

Operators in complex environments are often supported by alarm systems that indicate when to shift attention to certain tasks. As alarms are not perfectly reliable, operators have to select appropriate strategies of attention allocation to compensate for unreliability and to maintain overall performance. This study explores how humans adapt to differing alarm reliabilities. Within a multi-task simulation consisting of a monitoring task and two other concurrent tasks, participants were assigned to one of five groups. In the manual control group none of the tasks was supported by an alarm system, whereas the four experimental groups were supported in the monitoring task by a miss-prone alarm system differing in reliability, i.e. 68.75%, 75%, 87.5%, 93.75%. Compared to the manual control group, all experimental groups benefited from the support by alarms, with best performance for the highest reliability condition. However, for the lowest reliability group the benefit was associated with an increased attentional effort, a more demanding attention allocation strategy, and a declined relative performance in a concurrent task. Results are discussed in the context of recent automation research.

Responding to alarm systems which usually commit a number of false alarms and/or misses involves decision-making under uncertainty. Four laboratory experiments including a total of 256 participants were conducted to gain comprehensive insight into humans' dealing with this uncertainty. Specifically, it was investigated how responses to alarms/non-alarms are affected by the predictive validities of these events, and to what extent response strategies depend on whether or not the validity of alarms/non-alarms can be cross-checked against other data. Among others, the results suggest that, without cross-check possibility (experiment 1), low levels of predictive validity of alarms ( ≤ 0.5) led most participants to use one of two different strategies which both involved non-responding to a significant number of alarms (cry-wolf effect). Yet, providing access to alarm validity information reduced this effect dramatically (experiment 2). This latter result emerged independent of the effort needed for cross-checkings of alarms (experiment 3), but was affected by the workload imposed by concurrent tasks (experiment 4). Theoretical and practical consequences of these results for decision-making and response selection in interaction with alarm systems, as well as the design of effective alarm systems, are discussed.

Dieser Beitrag ist mit Zustimmung des Rechteinhabers aufgrund einer (DFG geförderten) Allianz- bzw. Nationallizenz frei zugänglich., This publication is with permission of the rights owner freely accessible due to an Alliance licence and a national licence (funded by the DFG, German Research Foundation) respectively., Spatial disorientation (SD) is a common factor in aviation accidents, especially in novice pilots. An experiment was carried out to determine which of four different attitude indicator concepts in combination with two different display backgrounds (abstract vs. synthetic landscape) proves to be the most beneficial for novice pilot performance. Inexperienced pilots had to recover from unusual attitudes by using the standard moving-horizon display, a moving-aircraft display, a frequency-separated display, and a “mixed” display, with the latter two representing hybrid concepts with movements of both aircraft symbol and horizon bar. Participants performed the task of recovering from unusual attitudes most efficiently with hybrid display concepts, suggesting that these display concepts prevent figure-ground reversals and associated pilot errors. Outcomes of the study suggest that the implementation of hybrid display concepts as a backup option when unwillingly entering Instrument Flight Conditions could be a solution for preventing SD in novice pilots.

BACKGROUND The Head and Neck Cancer Tumor Board is a multispeciality comprehensive conference that brings together experts with different backgrounds to make group decisions about the appropriate treatment. Due to the complexity of the patient cases and the collaboration of different medical disciplines most of these decisions have to be made under uncertainty, i. e., with-out knowing all relevant factors and without being quite sure about the outcome. METHODS To develop effective team decision making under uncertainty, it is necessary to understand how medical experts perceive and handle uncertainties. The aim of this field study was to develop a knowledge base by exploring additionally the factors that influence group decision making processes. A structured nonparticipant observational study was employed to address the research goal. Video data were analyzed by 2 independent observers using an observation checklist. A total of 20 videotaped case discussions were studied. Observations were complemented by a questionnaire gathering subjective evaluations of board members about the process and quality of their decisions (N=15). RESULTS The results show that uncertainty is recognized by board members. Reasons for uncertainty may stem from the complexity of the cases (e. g. therapy options) or the assessment from different disciplines coming together at the board. CONCLUSION With respect to handling uncertainty and guaranteeing an optimal decision making process potential for improvement could be defined. This pertains to the handling of different levels of competence, the promotion of a positive discussion culture as well as structuring of the decision making process.

Providing access towards raw data is often considered to be a good solution for improving human decision making in interaction with imperfect automated decision support such as alarm systems. However, there is some evidence that such cross-checking measures are used in an asymmetric manner with respect to the amount of uncertainty involved in the decision. Namely, people seem to accept low amounts of uncertainty when complying with an alarm cue, but not when contradicting it. The current study investigates the question whether this phenomenon is limited to alarm systems and a high risk environment. Within a multi-task PC simulation participants performed a low risk monitoring task which was supported by a system neutrally framed as “assistant system”. In one group the cues emitted by the system were 90% correct, in the other 10% were correct, thus causing a 10% uncertainty about the real state in both conditions. Results show a strong asymmetry as participants in the latter condition spent a high amount of effort in reducing their uncertainty, while participants in the former condition did not. Furthermore participants’ behavior almost exactly replicates the asymmetric cross-checking pattern found in a former study which employed a comparatively high risk monitoring task supported by an “alarm system”. This supports the hypothesis that the observed commission bias represents a general phenomenon in the context of automated decision support, irrespective of the risk attributed to the environment and irrespective of whether the system represents an alarm system or not.

Understanding the mechanisms and performance consequences of multitasking has long been in focus of scientific interest, but has been investigated by three research lines more or less isolated from each other. Studies in the fields of the psychological refractory period, task switching, and interruptions have scored with a high experimental control, but usually do not give participants many degrees of freedom to self-organize the processing of two concurrent tasks. Individual strategies as well as their impact on efficiency have mainly been neglected. Self-organized multitasking has been investigated in the field of human factors, but primarily with respect to overall performance without detailed investigation of how the tasks are processed. The current work attempts to link aspects of these research lines. All of them, explicitly or implicitly, provide hints about an individually preferred type of task organization, either more cautious trying to work strictly serially on only one task at a time or more daring with a focus on task interleaving and, if possible, also partially overlapping (parallel) processing. In two experiments we investigated different strategies of task organization and their impact on efficiency using a new measure of overall multitasking efficiency. Experiment 1 was based on a classical task switching paradigm with two classification tasks, but provided one group of participants with a stimulus preview of the task to switch to next, enabling at least partial overlapping processing. Indeed, this preview led to a reduction of switch costs and to an increase of dual-task efficiency, but only for a subgroup of participants. They obviously exploited the possibility of overlapping processing, while the others worked mainly serially. While task-sequence was externally guided in the first experiment, Experiment 2 extended the approach by giving the participants full freedom of task organization in concurrent performance of the same tasks. Fine-grained analyses of response scheduling again revealed individual differences regarding the preference for strictly serial processing vs. some sort of task interleaving and overlapping processing. However, neither group showed a striking benefit in dual-task efficiency, although the results show that the costs of multitasking can partly be compensated by overlapping processing.

Dieser Beitrag ist mit Zustimmung des Rechteinhabers aufgrund einer (DFG geförderten) Allianz- bzw. Nationallizenz frei zugänglich. This publication is with permission of the rights owner freely accessible due to an Alliance licence and a national licence (funded by the DFG, German Research Foundation) respectively. The objective of this panel was to discuss issues related to the development and use of autonomous systems, with specific focus on the overriding themes of ethical considerations and potential liability for Human Factors and Ergonomics (HF/E) professionals who are involved in their development. Chris Brill provided opening remarks to frame the discussion and introduce the panelists. James Bliss discussed legal implications related to our collective penchant for developing conservative, false-alarm prone automation. Peter Hancock advocated for human-centered constraints on autonomous systems, as they may, one day, pose an existential threat to humanity. Dietrich Manzey discussed ethical considerations for autonomous systems, including how design can encourage ethical user behavior. Joachim Meyer argued that HF/E professionals have an obligation to help designers understand the ethical implications of poor design, particularly in the context of autonomous systems. Lastly, Alison Vredenburgh provided thoughts on potential liability for HF/E professionals, particularly in light of the relative newness of autonomous systems. The panel then turned to facilitated discussion with panelists and audience members. Specific themes included the boundaries of our responsibilities as HF/E professionals for ill-conceived or morally-objectionable systems, potential implications of manipulating user trust through design, cross-cultural perspectives on public acceptance and legal peril, and how concerns might differ by domain (e.g., medical vs. combat vs. manufacturing). The session concluded with panelists summarizing how ethics influence design and recommendations for how HF/E professionals can potentially protect themselves from legal liability for mishaps involving autonomous systems they helped develop.