Human Factors最新文献

ObjectiveThe objective of this study is to empirically test a computational model of interruptions processes and effects, and to compare an alternative model to determine which best explains interruption and response decision making.BackgroundInterruptions in safety-critical environments (e.g., hospitals) can lead to an increased risk of error for the person being interrupted (the interruptee) but may be necessary for the person doing the interrupting (the interrupter) to maintain safety. Little research has considered the perspective of both the interrupter and interruptee.MethodWe tested a computational model of interruption and response decision processes through an experiment where participants (n = 312) worked as a nurse in a simulated clinical team. We examined how task progress, time remaining, and time pressure influenced decisions and compared the model with an alternative that allowed the effects of time pressure to be non-monotonic.ResultsUsing Bayesian hierarchical modeling, we found that a non-monotonic model best explained interruption decisions. Participants were biased toward interrupting, with time pressure only influencing decisions when it was very high. Contrastingly, the monotonic model best explained response decisions. Participants were more likely to accept interruptions as the interrupter's time pressure increased in comparison to their own.ConclusionTime pressure has a non-monotonic influence on interruption decisions, but a monotonic influence on response decisions.ApplicationFindings can inform interventions to consider the interruptions process from the perspective of both the interrupter and interruptee. Interventions could focus on training workers to more accurately assess time pressure when making interruption decisions.

ObjectiveThis research investigated effects for new traffic markings on the user behaviour of motorcycle riders.BackgroundAcross motorised vehicles, motorcycles represent the most vulnerable road users.MethodA road sign and traffic markings were installed at six trial sites. Data from video cameras at each site provided measures of rider behaviour in relation to speed, road position, brake use, and use of the traffic markings, before and after installations. Throughout this research 4652 motorcycle riders travelled through the sites. Of these 1542 riders were analysed in more detail to investigate the effects of the road safety intervention on rider behaviour.ResultsAt five sites speed was reduced by a significant margin. At four sites there were significant improvements in road position at the final traffic marking. At five of the trial sites on the apex of a bend, there were significant improvements in road position. Braking behaviour decreased at two of the trial sites. For use of the traffic markings a significant increase was observed across all the trial sites. Across the behaviour measures, the changes were still present 4 weeks later. At a comparison site no changes in behaviour were observed.ConclusionThe findings provide evidence of improved rider behaviour which are placed in reference to the Safe System principles for road safety and casualty reduction.ApplicationThis research has generated international interest for installing the road sign and traffic markings in other regions and contributes to the Scottish Government's Road Safety Framework to 2030 by reducing motorcycle casualties.

ObjectiveThis study examines the disuse of technology among older adults and develops a taxonomy to categorize various forms of disuse.BackgroundUnderstanding the prevalence and factors contributing to disuse is challenging due to the varying terminology and lack of a standard classification. This lack of clarity makes it difficult to understand the reasons for the disuse of technology, especially when studying the use of emerging assistive technology among older adults. This is problematic, as these emerging technologies offer numerous benefits, but many adults struggle to incorporate them into their daily lives, resulting in disuse.MethodWe analyzed open-ended survey responses from 78 older adults who had purchased but subsequently disused a smart speaker. We employed a reflexive thematic analysis to identify themes related to the disuse of technology.ResultsTwo overarching themes were identified. The first, "Interests and Purchase Influences," captured the initial reasons for adoption, ranging from general curiosity to meeting specific needs. The second, "Misalignment with Needs and Expectations," encompassed four subthemes: disspointment, lack of relevance, perceived risks, and impact on independence, which collectively explained why participants ultimately stopped using the device.ConclusionThese findings demonstrate how varied experiences with the same technology result in distinct disuse trajectories, highlighting the gap between adoption and disuse research. Clarifying these patterns strengthens the disuse taxonomy and lays the groundwork for future studies to quantify their impact.

ObjectiveThe objective of the current study is to investigate how passive exoskeletons affect low-back passive tissues creep during prolonged stooping.BackgroundUsing exoskeletons could be a new strategy to prevent stress-relaxation deformation (creep) in low-back passive tissues induced by prolonged or repetitive stooping, but previous studies only focused on low-back active tissues.MethodTwelve healthy males completed 12 min of stooping (with and without a passive exoskeleton), while body kinematics and muscle activities were captured before and after stooping.ResultsResults indicate intact characteristics (i.e., no changes) in both active and passive tissues after enduring a 12-min stooping protocol while using the exoskeleton. However, without the exoskeleton, clear stress-relaxation deformation in low-back tissues, and changes in the load transfer mechanism between active and passive tissues after prolonged stooping, are observed, revealing a 3.19° delayed flexion-relaxation angle, a 5% maximum voluntary contraction increase in lumbar muscle activity, and a 2.8° increase in the maximum lumbar flexion angle.ConclusionThe supporting force provided by passive exoskeletons effectively limits stress-relaxation deformation in low-back passive tissues, such as ligaments, by preventing excessive elongation during prolonged stooping in a fully flexed posture, thereby reducing the possible risk of spinal instability and low back pain development.ApplicationThe study reveals the greater value of passive exoskeletons, which protect passive tissues in the low back. The research findings can serve as a valuable reference for practitioners in implementing effective countermeasures in the perspective of assistance devices to enhance occupational safety.

ObjectiveInvestigators assessed whether a simplified runway status light (specifically runway entrance lights) may reduce the risk of runway incursions in nontowered airport environments.BackgroundComplementing the development of a low-cost aircraft surveillance system, the authors proposed the use of runway status lights at nontowered airports, an environment in which such systems have previously not been tested.MethodThirty-seven general aviation pilots were recruited to participate in three simulated scenarios with and without runway status lights. Participants were tasked with deciding when to take off from a runway. Participants' performance was assessed to determine whether simplified runway status lights impacted the risk of runway incursions, or how quickly a takeoff decision was made. The effect of the provision of system information on participants' performance was also studied. A NASA TLX questionnaire was administered to measure the perceived workload effects of runway status lights use while a survey captured participants' views on runway status light use.ResultsSimplified runway status lights reduced runway incursion risk in simulated scenarios when conflicting aircraft were relatively difficult to see. The provision of training or system information appeared desirable but not necessary, based on participants' feedback and performance. A reduction in perceived workload (physical domain) was reported in scenarios with runway status lights. Overall, participants had positive views on the implementation of runway status lights.ConclusionSimplified runway status lights may be effective at mitigating runway incursion risk.ApplicationThese findings support the continued study of runway status lights at more airports, including nontowered airports.

ObjectiveThe current study aimed to explore the impacts of experiencing superior behaviors-accumulating large amounts of evidence and high automation use rates-on subsequent evidence accumulation rates and adaptable (discretionary) automation use decisions in a dynamic decision-making task.BackgroundOperators prefer to choose when to engage automated support systems but seldom use them appropriately. They also do not typically collect enough evidence to optimize their decision making. This creates suboptimal performance that could benefit from training better behaviors.MethodParticipants collected evidence about movement patterns of ships while assisted by a machine learning aid. They were initially required to collect high levels of evidence and use the aid as a form of hands-on training. Then, they chose how much evidence to collect and when to engage the aid.ResultsWhen given the choice, operators collected less evidence and used the automation less often than had been required during training, but improved their performance compared to unaided trials.ConclusionProviding operators with early experience of superior behavioral strategies can improve their subsequent decisions. This is a promising direction for achieving human-automation team synergy.ApplicationsShort exposures to optimal behaviors may be a feasible training approach to improve human-automation interactions in contexts where operators want decisional freedom in their interactions.

ObjectiveThis study investigated the effect of sharing vehicle situation awareness (VSA) on driver takeover behavior in complex urban environments.BackgroundAs automated vehicles (AV) expand their operational design domain, little is known about driver interactions with driving automation in complex urban settings. Drivers often become either overly reliant on automation or fail to rely on it even when capable, leading to misuse or disuse. Sharing VSA information could enhance drivers' awareness of the AV system and response when AVs request manual control in complex situations.MethodsA driving simulator tested sharing VSA information via augmented reality head-up displays (AR HUDs) during takeover scenarios. Participants were assigned to control or experimental groups that received different combinations of VSA elements: perception (object highlighting), comprehension (confidence assessment), and projection (trajectory information). Two urban driving scenarios (parking lane and intersection) were tested.ResultsSharing VSA information reduced driver-initiated automation disengagement before takeover requests without delaying response times. Perception information alone showed no significant difference from baseline, but adding egocentric projection information significantly reduced driver-initiated overrides, while allocentric projection did not. Adding confidence assessment further enhanced effectiveness. The parking lane scenario was associated with quicker responses, fewer full takeovers, and softer braking.ConclusionSpecific combinations of VSA information reduced driver-initiated disengagement from automation without compromising response times. The type and presentation of shared information significantly affect human-automation interaction.ApplicationThese findings can guide the design of AV systems that better support driver-vehicle interaction in complex urban environments.

ObjectiveThis study investigates how users' trust evolves during their first ride in a fully driverless robotaxi and how it can be affected by user characteristics, system design, and traffic scenarios.BackgroundAs driving automation technology matures, driverless robotaxis have become available. Despite its immense economic and social potential, public acceptance can be strongly influenced by user trust. Previous research on trust in autonomous vehicles often relied on surveys, driving simulators, or "Wizard of Oz" methods, potentially introducing biases.MethodAn on-road experiment was conducted in commercially operating fully driverless robotaxis on public urban roads. In total, 30 participants with no prior experience riding fully driverless robotaxis were recruited, comprising nondrivers (n = 10), and drivers with (n = 10) and without (n = 10) driving automation experience. Dynamic trust was collected at a 2-min interval during the ride, along with participants' think-aloud for changes in trust. A cumulative link mixed model was used to assess the impact of past driving experience, demographics, and riding time on trust development.ResultsOur findings revealed that dynamic trust increased gradually and stabilized over time, with user heterogeneity playing a moderating role in this process. Further think-aloud data analysis identified key factors in trust formation, including driving style, riding safety and comfort, and user interface design.ConclusionTrust in driverless robotaxis builds progressively with real-world exposure, shaped by user characteristics, vehicle control, and interface design.ApplicationOur findings underscore the importance of considering user heterogeneity in fostering trust and acceptance of robotaxis.

ObjectiveThe aim of this study was to explore the effect of contrast and spatial frequency intensities in a virtual environment on quiet, upright stance.BackgroundVisual feedback provides crucial sensory information to maintain postural control. Changes to contrast sensitivity and spatial frequency in the environment have been shown to influence postural stability; however, there is currently no work examining the influence of environmental contrast and spatial frequency on balance among young healthy populations.Methodology28 healthy participants stood on a force plate, feet together, while wearing a head-mounted display. Participants viewed a virtual room and were exposed to four 60s conditions, each with a modified level of contrast (low or high) and spatial frequency (low or high) of the surrounding wallpaper. Center of pressure and head displacement root mean square and mean power frequency were calculated to quantify balance behavior.ResultsHigher contrast reduced sway, particularly along the AP axis and on a foam surface (COP AP RMS foam: 7.56 ± 1.92 mm vs. 8.61 ± 1.70 mm; HMD AP RMS: 7.46 ± 2.57 mm vs. 8.92 ± 3.20 mm, mean ± SD). Spatial frequency affected only COP ML RMS on foam, with lower spatial frequencies producing slightly greater sway amplitude (7.93 ± 1.93 mm vs. 7.42 ± 1.75 mm).ConclusionIn conclusion, the level of both contrast and spatial frequency in the surrounding environment impact balance control during quiet, upright stance.ApplicationThis study suggests visual environmental cues should be considered when designing environments to reduce fall risk.

ObjectiveThis study examined whether a powered ankle exoskeleton affected street crossing decisions and perceived mental workload of novice users without mobility limitations at a simulated traffic intersection.BackgroundExoskeletons are wearable mobility devices that can impact physical and cognitive performance. Exoskeleton commercialization for the public necessitates evaluations into how these systems influence novices' cognitive reasoning and directed attention in urban environments.MethodsParticipants (n = 20) made street crossing decisions with and without the exoskeleton. Participants walked through a simulated city using a self-paced treadmill and decided whether to cross the street at prespecified distances from the intersection. Cognitive workload perception was measured using the NASA-TLX survey.ResultsNo significant effects of the exoskeleton on street crossing decisions were observed. Rather, data indicated significant reductions in decisions to cross as distance from the intersection increased and with vehicle presence at the intersection. Cognitive workload scores marginally worsened when wearing the exoskeleton.ConclusionStreet crossing decisions were unaffected, but exoskeletons can influence perceived mental workload. These results highlight the importance of designing wearable systems that align with both physical and cognitive task demands. Future studies should incorporate different exoskeletons, tasks, and user groups to determine how these factors influence task performance.ApplicationUnderstanding the interaction between exoskeletons and novice user cognitions can support the development of exoskeletons that provide sufficient physical support without impeding the mental processes needed for their safe and efficient operation. Researchers can also utilize similar procedures to evaluate alternate exoskeleton designs for urban mobility decision making.