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This theoretical article examines the concept of social support in the context of human-automation interaction, outlining several critical issues. We identified several factors that we expect to influence the consequences of social support and to what extent it is perceived as appropriate (e.g. provider possibilities, recipient expectations), notably regarding potential threats to self-esteem. We emphasise the importance of performance (including extra-role performance) as a potential outcome, whereas previous research has primarily concentrated on health and well-being. We discuss to what extent automation may provide different types of social support (e.g. emotional, instrumental), and how it differs from human support. Finally, we propose a taxonomy of automated support, arguing that source of support is not a binary concept. We conclude that more empirical work is needed to examine the multiple effects of social support for core performance indicators and extra-role performance and emphasise that there are ethical questions involved.

This theoretical article examines the role of automated social support given the increasing ability of automated systems. It concludes that it seems likely that automated systems may be perceived as supportive if they conform to pertinent criteria for design. However, empirical studies are needed to assess the impact of the complex interplay of humans and automation being involved together in the design and provision of social support.

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Hybrid teaching (synchronous online and on-site teaching) offers many advantages (e.g., increased flexibility). However, previous research has suggested that students who join classes online suffer higher levels of distractibility, which might translate into students engaging in more off-task activities. This, in turn, can impair students' learning performance. The following quasi-experimental field study investigated this specific link between teaching mode, engagement in off-task activities, and learning performance. We collected survey data from N = 690 students in six hybrid classes (N = 254 online, N = 436 on-site). Participants reported the amount of time they spent engaging in digital and non-digital off-task activities and responded to a quiz on the course material. Results revealed that online students spent more time engaging in off-task activities than on-site students. Further, results were consistent with our hypothesis that joining the class online is associated with lower learning performance via time spent on digital off-task activities.

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This dataset contains data of 346 drivers collected during six experiments conducted in a fixed-base driving simulator. Five studies simulated conditionally automated driving (L3-SAE), and the other one simulated manual driving (L0-SAE). The dataset includes physiological data (electrocardiogram (ECG), electrodermal activity (EDA), and respiration (RESP)), driving and behavioral data (reaction time, steering wheel angle, …), performance data of non-driving-related tasks, and questionnaire responses. Among them, measures from standardized questionnaires were collected, either to control the experimental manipulation of the driver's state, or to measure constructs related to human factors and driving safety (drowsiness, mental workload, affective state, situation awareness, situational trust, user experience). In the provided dataset, some raw data have been processed, notably physiological data from which physiological indicators (or features) have been calculated. The latter can be used as input for machine learning models to predict various states (sleep deprivation, high mental workload, ...) that may be critical for driver safety. Subjective self-reported measures can also be used as ground truth to apply regression techniques. Besides that, statistical analyses can be performed using the dataset, in particular to analyze the situational awareness or the takeover quality of drivers, in different states and different driving scenarios. Overall, this dataset contributes to better understanding and consideration of the driver's state and behavior in conditionally automated driving. In addition, this dataset stimulates and inspires research in the fields of physiological/affective computing and human factors in transportation, and allows companies from the automotive industry to better design adapted human-vehicle interfaces for safe use of automated vehicles on the roads.

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Drivers are often held responsible for road crashes. Previous research has shown that stressors such as carrying passengers in the vehicle can be a source of accidents for young drivers. To mitigate this problem, this study investigated whether the presence of a passenger behind the wheel can be predicted using machine learning, based on physiological signals. It also addresses the question whether relaxation before driving can positively influence the driver's state and help controlling the potential negative consequences of stressors. Sixty young participants completed a 10-min driving simulator session, either alone or with a passenger. Before their driving session, participants spent 10 min relaxing or listening to an audiobook. Physiological signals were recorded throughout the experiment. Results show that drivers experience a higher increase in skin conductance when driving with a passenger, which can be predicted with 90%-accuracy by a k-nearest neighbors classifier. This might be a possible explanation for increased risk taking in this age group. Besides, the practice of relaxation can be predicted with 80% accuracy using a neural network. According to the statistical analysis, the potential beneficial effect of relaxation did not carry out on the driver's physiological state while driving, although machine learning techniques revealed that participants who exercised relaxation before driving could be recognized with 70% accuracy. Analysis of physiological characteristics after classification revealed several relevant physiological indicators associated with the presence of a passenger and relaxation.

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In previous research, microsaccades have been suggested as psychophysiological indicators of task load. So far, it is still under debate how different types of task demands are influencing microsaccade rate. This piece of research examines the relation between visual load, mental load and microsaccade rate. Fourteen participants carried out a continuous performance task (n-back), in which visual (letters vs. abstract figures) and mental task load (1-back to 4-back) were manipulated as within-subjects variables. Eye tracking data, performance data as well as subjective workload were recorded. Data analysis revealed an increased level of microsaccade rate for stimuli of high visual demand (i.e. abstract figures), while mental demand (n-back-level) did not modulate microsaccade rate. In conclusion, the present results suggest that microsaccade rate reflects visual load of a task rather than its mental load.

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The use of automation in cars is increasing. In future vehicles, drivers will no longer be in charge of the main driving task and may be allowed to perform a secondary task. However, they might be requested to regain control of the car if a hazardous situation occurs (i.e., conditionally automated driving). Performing a secondary task might increase drivers' mental workload and consequently decrease the takeover performance if the workload level exceeds a certain threshold. Knowledge about the driver's mental state might hence be useful for increasing safety in conditionally automated vehicles. Measuring drivers' workload continuously is essential to support the driver and hence limit the number of accidents in takeover situations. This goal can be achieved using machine learning techniques to evaluate and classify the drivers' workload in real-time. To evaluate the usefulness of physiological data as an indicator for workload in conditionally automated driving, three physiological signals from 90 subjects were collected during 25 min of automated driving in a fixed-base simulator. Half of the participants performed a verbal cognitive task to induce mental workload while the other half only had to monitor the environment of the car. Three classifiers, sensor fusion and levels of data segmentation were compared. Results show that the best model was able to successfully classify the condition of the driver with an accuracy of 95%. In some cases, the model benefited from sensors' fusion. Increasing the segmentation level (e.g., size of the time window to compute physiological indicators) increased the performance of the model for windows smaller than 4 min, but decreased for windows larger than 4 min. In conclusion, the study showed that a high level of drivers' mental workload can be accurately detected while driving in conditional automation based on 4-min recordings of respiration and skin conductance.

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Aesthetically appealing stimuli can improve performance in demanding target localisation tasks compared to unappealing stimuli. Two search-and-localisation experiments were carried out to examine the possible underlying mechanism mediating the effects of appeal on performance. Participants (N = 95) were put in a positive or negative mood prior to carrying out a visual target localisation task with appealing and unappealing targets. In both experiments, positive mood initially led to faster localisation of appealing compared to unappealing stimuli, while an advantage for appealing over unappealing stimuli emerged over time in negative mood participants. The findings are compatible with the idea that appealing stimuli may be inherently rewarding, with aesthetic appeal overcoming the detrimental effects of negative mood on performance.

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Within the field of ergonomics, the concepts of usability, user experience and accessibility have played an increasingly important role. The present paper examined the meaning of these concepts and their relationship to each other, which included an analysis of the definitions, methods, and typical outcome measures employed. Despite some concerns in the literature about the utility of usability, user experience and accessibility as umbrella terms, we provide arguments for their continued use. The article proposes how the three concepts and their different perspectives can be integrated. We propose the term 'interaction experience' (IX) as a higher-level concept. Due to the multi-facetted nature of umbrella concepts, we suggest using spider charts as a means to report the results of evaluating artefacts with regard to usability, user experience and accessibility. Practitioner Summary: A better integration of the concepts of usability, user experience and accessibility is expected to provide some benefits to practitioners. We propose employing spider charts for reporting the outcome of artefact evaluations regarding the three concepts. This may help practitioners interpret the characteristics of a device at a glance. Abbreviations: IX: interaction experience; UX: user experience; ISO: International Standard Organisation.

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INTRODUCTION: Findings of recent studies indicate that it is possible to enhance cognitive capacities of healthy individuals by means of individual upper alpha neurofeedback training (NFT). Although these results are promising, most of this research was conducted based on high-priced EEG systems developed for clinical and research purposes. This study addresses the question whether such effects can also be shown with an easy to use and comparably low-priced Emotiv Epoc EEG headset available for the average consumer. In addition, critical voices were raised regarding the control group designs of studies addressing the link between neurofeedback training and cognitive performance. Based on an extensive literature review revealing considerable methodological issues in an important part of the existing research, the present study addressed the question whether individual upper alpha neurofeedback has a positive effect on alpha amplitudes (i.e. increases alpha amplitudes) and short-term memory performance focussing on a methodologically sound, single-blinded, sham controlled design. METHOD: Participants (N = 33) took part in four test sessions over four consecutive days of either neurofeedback training (NFT group) or sham feedback (SF group). In the NFT group, five three-minute periods of visual neurofeedback training were administered each day whereas in the SF group (control group), the same amount of sham feedback was presented. Performance on eight digit-span tests as well as participants' affective states were assessed before and after each of the daily training sessions. RESULTS: NFT did not show an effect on individual upper alpha and cognitive performance. While performance increased in both groups over the course of time, this effect could not be explained by changes in individual upper alpha. Additional analyses however revealed that participants in the NFT group showed faster and larger increase in alpha compared to the SF group. Surprisingly, exploratory analyses showed a significant correlation between the initial alpha level and the alpha improvement during the course of the study. This finding suggests that participants with high initial alpha levels benefit more from alpha NFT interventions. In the discussion, the appearance of the alpha enhancement in the SF group and possible reasons for the absence of a connection between NFT and short-term memory are addressed.

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Given the increasing capabilities of highly automated systems, the article argues for a need to address the issue of social stress in human-machine interaction. It suggests a classification system of subordinate concepts found in the research literature under the heading of social stress. A review of the literature revealed a paucity of studies examining the effects of social stressors on performance. In particular, the review showed a shortage of experimental lab-based work, needed to establish clear cause-effect relationships. The article examined the suitability of different social stressors for lab-based research, not only when humans are the source of stress but also in so-called hybrid teams where social stress is caused by machine agents. The review shows that a closer link is needed between the separate literature on social stress and automation. Finally, three mechanisms are proposed that may predict how social stress may affect performance: 'blank-out'-mechanism, 'rumination'-mechanism, and 'increased-motivation'-mechanism. Practitioner summary: Theories of ergonomics and human factors may benefit from better integration of research and theoretical work in the domain of social stress. This is due to the increasing capabilities of machines to induce social stress. Abbreviations: HMI: human-machine interaction; TSST: trier social stress test.

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Understanding our visual world requires both looking and seeing. Dissociation of these processes can result in the phenomenon of inattentional blindness or 'looking without seeing'. Concomitant errors in applied settings can be serious, and even deadly. Current visual data analysis cannot differentiate between just 'looking' and actual processing of visual information, i.e., 'seeing'. Differentiation may be possible through the examination of microsaccades; the involuntary, smallmagnitude saccadic eye movements that occur during processed visual fixation. Recent work has suggested that microsaccades are post-attentional biosignals, potentially modulated by task. Specifically, microsaccade rates decrease with increased mental task demand, and increase with growing visual task difficulty. Such findings imply that there are fundamental differences in microsaccadic activity between visual and nonvisual tasks. To evaluate this proposition, we used a high-speed eye tracker to record participants in looking for differences between two images or, doing mental arithmetic, or both tasks in combination. Results showed that microsaccade rate was significantly increased in conditions that require high visual attention, and decreased in conditions that require less visual attention. The results support microsaccadic rate reflecting visual attention, and level of visual information processing. A measure that reflects to what extent and how an operator is processing visual information represents a critical step for the application of sophisticated visual assessment to real world tasks.

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The present article examined the effects of using different extra-laboratorial testing procedures in usability testing. Three experiments were conducted using different artefacts (website, computer-simulated mobile phone, fully operational smartphone) to compare different methodological approaches in field testing (synchronous and asynchronous remote testing, classical field testing) to lab-based testing under different operational conditions (dual task demands, poor product usability). Typical outcome variables of usability testing were measured, including task completion time, click rate, perceived usability and workload. Overall, the results showed no differences between field and lab-based testing under favourable operational conditions. However, under difficult operational conditions (i.e. dual task demands, poor product usability) differences between field and lab-based testing emerged (corresponding to small and medium effect sizes). The findings showed a complex pattern of effects, suggesting that there was no general advantage of one testing procedure over another.

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This article examines the influence of using easy-to-read language (as an important web accessibility criterion to support users with disabilities) on nondisabled users. A web site usability test was conducted with 128 nondisabled participants. Each participant evaluated one of two web site versions: conventional language vs. easy-to-read language. Measures of performance (e.g., recognition of content and reading time) and subjective user reactions (e.g., perceived usability and text liking) were taken. The results showed that easy-to-read language (compared to conventional language) led to improvements for some performance measures (e.g., recognition of content) but also to increased reading time, decreased text liking and reduced intention to revisit the web site. This article concludes that when implementing easy-to-read language in web sites, adverse as well as beneficial effects on nondisabled users need to be considered.

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This study examined how implementing recommendations from Web accessibility guidelines affects nondisabled people in different age groups using different technical devices. While recent research showed positive effects of implementing such recommendations for nondisabled users, it remains unclear whether such effects would apply to different age groups and kind of devices. A 2 × 2 × 2 design was employed with website accessibility (high accessibility vs. very low accessibility), age (younger adults vs. older adults) and type of device (laptop vs. tablet) as independent variables. 110 nondisabled participants took part in a usability test, in which performance and satisfaction were measured as dependent variables. The results showed that higher accessibility increased task completion rate, task completion time and satisfaction ratings of nondisabled users. While user age did not have any effects, users showed faster task completion time under high accessibility when using a tablet rather than a laptop. The findings confirmed previous findings, which showed benefits of accessible websites for nondisabled users. These beneficial effects may now be generalised to a wide age range and across different devices. Practitioner Summary: This work is relevant to the design of websites since it emphasises the need to consider the characteristics of different user groups. Accessible website design (aimed at users with disabilities) leads to benefits for nondisabled users across different ages. These findings provide further encouragement for practitioners to apply WCAG 2.0.

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OBJECTIVE: The present study examined whether implementing recommendations of Web accessibility guidelines would have different effects on nondisabled users than on users with visual impairments. BACKGROUND: The predominant approach for making Web sites accessible for users with disabilities is to apply accessibility guidelines. However, it has been hardly examined whether this approach has side effects for nondisabled users. A comparison of the effects on both user groups would contribute to a better understanding of possible advantages and drawbacks of applying accessibility guidelines. METHOD: Participants from two matched samples, comprising 55 participants with visual impairments and 55 without impairments, took part in a synchronous remote testing of a Web site. Each participant was randomly assigned to one of three Web sites, which differed in the level of accessibility (very low, low, and high) according to recommendations of the well-established Web Content Accessibility Guidelines 2.0 (WCAG 2.0). Performance (i.e., task completion rate and task completion time) and a range of subjective variables (i.e., perceived usability, positive affect, negative affect, perceived aesthetics, perceived workload, and user experience) were measured. RESULTS: Higher conformance to Web accessibility guidelines resulted in increased performance and more positive user ratings (e.g., perceived usability or aesthetics) for both user groups. There was no interaction between user group and accessibility level. CONCLUSION: Higher conformance to WCAG 2.0 may result in benefits for nondisabled users and users with visual impairments alike. APPLICATION: Practitioners may use the present findings as a basis for deciding on whether and how to implement accessibility best.

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OBJECTIVE: We examined the consequences of implementing Web accessibility guidelines for nondisabled users. BACKGROUND: Although there are Web accessibility guidelines for people with disabilities available, they are rarely used in practice, partly due to the fact that practitioners believe that such guidelines provide no benefits, or even have negative consequences, for nondisabled people, who represent the main user group of Web sites. Despite these concerns, there is a lack of empirical research on the effects of current Web accessibility guidelines on nondisabled users. METHOD: Sixty-one nondisabled participants used one of three Web sites differing in levels of accessibility (high, low, and very low). Accessibility levels were determined by following established Web accessibility guidelines (WCAG 2.0). A broad methodological approach was used, including performance measures (e.g., task completion time) and user ratings (e.g., perceived usability). RESULTS: A high level of Web accessibility led to better performance (i.e., task completion time and task completion rate) than low or very low accessibility. Likewise, high Web accessibility improved user ratings (i.e., perceived usability, aesthetics, workload, and trustworthiness) compared to low or very low Web accessibility. There was no difference between the very low and low Web accessibility conditions for any of the outcome measures. CONCLUSION: Contrary to some concerns in the literature and among practitioners, high conformance with Web accessibility guidelines may provide benefits to users without disabilities. APPLICATION: The findings may encourage more practitioners to implement WCAG 2.0 for the benefit of users with disabilities and nondisabled users.

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The effects of age in usability testing were examined in an experiment. Sixty users from two age groups (M = 23.0 yrs, M = 58.1 yrs) operated two technical devices (keyboard-based and touchscreen-based smartphones). In addition to various performance measures (e.g. task completion time, task completion rate), several subjective measures were taken (e.g. perceived usability, affect, and workload). The results showed better performance scores for younger adults than older adults for task completion time. For older adult users there was a mismatch between usability ratings and task completion time but not between usability ratings and task completion rate. Age-related differences in the importance of speed and accuracy in task completion point to the need to consider more strongly the factor user age in usability research and practice.

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Microsaccades are involuntary, small-magnitude saccadic eye movements that occur during attempted visual fixation. Recent research has found that attention can modulate microsaccade dynamics, but few studies have addressed the effects of task difficulty on microsaccade parameters, and those have obtained contradictory results. Further, no study to date has investigated the influence of task difficulty on microsaccade production during the performance of non-visual tasks. Thus, the effects of task difficulty on microsaccades, isolated from sensory modality, remain unclear. Here we investigated the effects of task difficulty on microsaccades during the performance of a non-visual, mental arithmetic task with two levels of complexity. We found that microsaccade rates decreased and microsaccade magnitudes increased with increased task difficulty. We propose that changes in microsaccade rates and magnitudes with task difficulty are mediated by the effects of varying attentional inputs on the rostral superior colliculus activity map.

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PURPOSE: To characterize side-to-side differences in the lower leg muscle-bone unit between the nondominant leg (NL) and the dominant leg (DL) using maximum voluntary forefoot ground reaction force (Fm1LH) during multiple one-legged hopping (m1LH) and tibial bone mass and geometry measured by peripheral quantitative computed tomography (pQCT). METHODS: Sixty-six male high-level soccer players (age range = 12-18 yr) performed m1LH to determine Fm1LH acting on the forefoot during landing for the NL and DL separately. pQCT scans were obtained to assess bone structural variables at 4%, 14%, 38%, and 66% tibia length and calf muscle cross-sectional area at the 66% site. RESULTS: First, participants displayed significant (P < 0.05) side-to-side differences in bone mass and geometry at 4%, 14%, and 38% (but not at the 66% site) of tibia length, with higher values in NL relative to DL (+0.7% to +5.6%), most evident at the 14% site. Second, no asymmetries were found for Fm1LH between the two legs (P = 0.442). Third, the relationship between Fm1LH and vBMC 14% was strong for both NL and DL (R2 = 0.48 and R = 0.54, respectively), but side-to-side differences in Fm1LH (ΔFm1LH) and side-to-side differences in vBMC 14% (ΔvBMC 14%) were not related (R2 = 0.04). CONCLUSIONS: Contrary to expectations from the mechanostat theory, ΔFm1LH and ΔvBMC 14% did not differ in proportion to each other. It seems that playing soccer is a well-balanced activity with respect to Fm1LH. However, the NL contributes to the supporting of the action of the DL, meaning that the loading experienced by the tibia might be more pronounced for the NL relative to the DL, leading to the observed higher bone strength values for the NL.

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This article examines the influence of socio-cultural background and product value on different outcomes of usability tests. A study was conducted in two different socio-cultural regions, Switzerland and East Germany, which differed in a number of aspects (e.g. economic power, price sensitivity and culture). Product value (high vs. low) was varied by manipulating the price of the product. Sixty-four test participants were asked to carry out five typical user tasks in the context of coffee machine usage, measuring performance, perceived usability, and emotion. The results showed that in Switzerland, high-value products were rated higher in usability than low-value products whereas in East Germany, high-value products were evaluated lower in usability. A similar interaction effect of socio-cultural background and product value was observed for user emotion. Implications are that the outcomes of usability tests do not allow for a simple transfer across cultures and that the mediating influence of perceived product value needs to be taken into consideration.

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