| 1. |
- Barbieri, Dechristian Franca, et al.
(author)
-
Comparison of sedentary behaviors in office workers using sit-stand tables with and without semi-automated position changes
- 2017
-
In: Human Factors. - : SAGE Publications. - 0018-7208 .- 1547-8181. ; 59:5, s. 782-795
-
Journal article (peer-reviewed)abstract
- Objective: This study compared usage patterns of two different electronically controlled sit-stand tables during a 2-month intervention period among office workers.Background: Office workers spend most of their working time sitting, which is likely detrimental to health. Although the introduction of sit-stand tables has been suggested as an effective intervention to decrease sitting time, limited evidence is available on usage patterns of sit-stand tables, and whether patterns are influenced by table configuration.Methods: Twelve workers were provided with standard sit-stand tables (non-automated table group) and 12 with semi-automated sit-stand tables programmed to change table position according to a pre-set pattern, if the user agreed to the system-generated prompt (semi-automated table group). Table position was monitored continuously for two months after introducing the tables, as a proxy for sit-stand behavior.Results: On average, the table was in a “sit” position for 85% of the work-day in both groups; this did not change significantly during the 2-month period. Switches in table position from sit to stand were, however, more frequent in the semi-automated table group than in the non-automated table group (0.65 vs. 0.29 hr-1; p=0.001).Conclusion: Introducing a semi-automated sit-stand table appeared to be an attractive alternative to a standard sit-stand table, since it led to more posture variation.Application: A semi-automated sit-stand table may effectively contribute to making postures more variable among office workers, and thus aid in alleviating negative health effects of extensive sitting.
|
|
| 2. |
- Kircher, Katja, 1973-, et al.
(author)
-
Minimum Required Attention : A Human-Centered Approach to Driver Inattention
- 2017
-
In: Human Factors. - : Sage Publications. - 0018-7208 .- 1547-8181. ; 59:3, s. 471-484
-
Journal article (peer-reviewed)abstract
- Objective: To propose a driver attention theory based on the notion of driving as a satisficing and partially self-paced task and, within this framework, present a definition for driver inattention.Background: Many definitions of driver inattention and distraction have been proposed, but they are difficult to operationalize, and they are either unreasonably strict and inflexible or suffer from hindsight bias.Method: Existing definitions of driver distraction are reviewed and their shortcomings identified. We then present the minimum required attention (MiRA) theory to overcome these shortcomings. Suggestions on how to operationalize MiRA are also presented.Results: MiRA describes which role the attention of the driver plays in the shared "situation awareness of the traffic system." A driver is considered attentive when sampling sufficient information to meet the demands of the system, namely, that he or she fulfills the preconditions to be able to form and maintain a good enough mental representation of the situation. A driver should only be considered inattentive when information sampling is not sufficient, regardless of whether the driver is concurrently executing an additional task or not.Conclusions: The MiRA theory builds on well-established driver attention theories. It goes beyond available driver distraction definitions by first defining what a driver needs to be attentive to, being free from hindsight bias, and allowing the driver to adapt to the current demands of the traffic situation through satisficing and self-pacing. MiRA has the potential to provide the stepping stone for unbiased and operationalizable inattention detection and classification.
|
|
| 3. |
- Liu, Zhuofan, et al.
(author)
-
Attentional Demand as a Function of Contextual Factors in Different Traffic Scenarios
- 2019
-
In: Human Factors. - : Sage Publications. - 0018-7208 .- 1547-8181. ; 62:17, s. 1171-1189
-
Journal article (peer-reviewed)abstract
- Objective: To assess the attentional demand of different contextual factors in driving.Background: The attentional demand on the driver varies with the situation. One approach for estimating the attentional demand, via spare capacity, is to use visual occlusion.Method: Using a 3 × 5 within-subjects design, 33 participants drove in a fixed-base simulator in three scenarios (i.e., urban, rural, and motorway), combined with five fixed occlusion durations (1.0, 1.4, 1.8, 2.2, and 2.6 s). By pressing a microswitch on a finger, the driver initiated each occlusion, which lasted for the same predetermined duration within each trial. Drivers were instructed to occlude their vision as often as possible while still driving safely.Results: Stepwise logistic regression per scenario indicated that the occlusion predictors varied with scenario. In the urban environment, infrastructure-related variables had the biggest influence, whereas the distance to oncoming traffic played a major role on the rural road. On the motorway, occlusion duration and time since the last occlusion were the main determinants.Conclusion: Spare capacity is dependent on the scenario, selected speed, and individual factors. This is important for developing workload managers, infrastructural design, and aspects related to transfer of control in automated driving.Application: Better knowledge of the determinants of spare capacity in the road environment can help improve workload managers, thereby contributing to more efficient and safer interaction with additional tasks.
|
|
| 4. |
- Lo, Julia C., et al.
(author)
-
Individual Markers of Resilience in Train Traffic Control : The Role of Operators' Goals and Strategic Mental Models and Implications for Variation, Expertise, and Performance
- 2016
-
In: Human Factors. - : SAGE Publications. - 0018-7208 .- 1547-8181. ; 58:1, s. 80-91
-
Journal article (peer-reviewed)abstract
- Objective: The aim of this study was to examine individual markers of resilience and obtain quantitative insights into the understanding and the implications of variation and expertise levels in train traffic operators' goals and strategic mental models and their impact on performance. Background: The Dutch railways are one of the world's most heavy utilized railway networks and have been identified to be weak in system and organizational resilience. Method: Twenty-two train traffic controllers enacted two scenarios in a human-in-the-loop simulator. Their experience, goals, strategic mental models, and performance were assessed through questionnaires and simulator logs. Goals were operationalized through performance indicators and strategic mental models through train completion strategies. Results: A variation was found between operators for both self-reported primary performance indicators and completion strategies. Further, the primary goal of only 14% of the operators reflected the primary organizational goal (i.e., arrival punctuality). An incongruence was also found between train traffic controllers' self-reported performance indicators and objective performance in a more disrupted condition. The level of experience tends to affect performance differently. Conclusion: There is a gap between primary organizational goals and preferred individual goals. Further, the relative strong diversity in primary operator goals and strategic mental models indicates weak resilience at the individual level. Application: With recent and upcoming large-scale changes throughout the sociotechnical space of the railway infrastructure organization, the findings are useful to facilitate future railway traffic control and the development of a resilient system.
|
|
| 5. |
- Prytz, Erik, 1985-, et al.
(author)
-
Fixation Differences in Visual Search of Accident Scenes by Novices and Expert Emergency Responders
- 2018
-
In: Human Factors. - : Sage Publications. - 0018-7208 .- 1547-8181. ; 60:8, s. 1219-1227
-
Journal article (peer-reviewed)abstract
- Objective:We sought to investigate whether expert–novice differences in visual search behavior found in other domains also apply to accident scenes and the emergency response domain.Background:Emergency service professionals typically arrive at accidents only after being dispatched when a civilian witness has called an emergency dispatch number. Differences in visual search behavior between the civilian witness (usually a novice in terms of emergency response) and the professional first responders (experts at emergency response) could thus result in the experts being given insufficient or erroneous information, which would lead them to arrive unprepared for the actual situation.Method:A between-subjects, controlled eye-tracking experiment with 20 novices and 17 experts (rescue and ambulance service personnel) was conducted to explore expert–novice differences in visual search of accident and control images.Results:The results showed that the experts spent more time looking at task-relevant areas of the accident images than novices did, as predicted by the information reduction hypothesis. The longer time was due to longer fixation durations rather than a larger fixation count.Conclusion:Expert–novice differences in visual search are present in the emergency domain. Given that this domain is essential to saving lives and also relies heavily on novices as the first link in the chain of response, such differences deserve further exploration.Application:Visual search behavior from experts can be used for training purposes. Eye-tracking studies of novices can be used to inform the design of emergency dispatch interviews.
|
|
| 6. |
- Sagberg, Fridulv, et al.
(author)
-
A Review of Research on Driving Styles and Road Safety
- 2015
-
In: Human Factors. - : SAGE Publications. - 1547-8181 .- 0018-7208. ; 57:No. 7, November 2015, s. 1248- 1275
-
Research review (peer-reviewed)abstract
- Objective: To outline a conceptual framework for understanding driving style and, based on this, review the state-of-the-art research on driving styles in relation to road safety.Background: Previous research has indicated a relationship between the driving styles adopted by drivers and their crash involvement. However, a comprehensive literature review of driving style research is lacking. Method: A systematic literature search was conducted, including empirical, theoretical and methodological research on driving styles related to road safety. Results: A conceptual framework was proposed where driving styles are viewed in terms of driving habits established as a result of individual dispositions as well as social norms and cultural values. Moreover, a general scheme for categorising and operationalizing driving styles was suggested. On this basis, existing literature on driving styles and indicators was reviewed. Links between driving styles and road safety were identified and individual and socio-cultural factors influencing driving style were reviewed. Conclusion: Existing studies have addressed a wide variety of driving styles, and there is an acute need for a unifying conceptual framework in order to synthesise these results and make useful generalisations. There is a considerable potential for increasing road safety by means of behaviour modification. Naturalistic driving observations represent particularly promising approaches to future research on driving styles. Application: Knowledge about driving styles can be applied in programmes for modifying driver behaviour and in the context of usage-based insurance. It may also be used as a means for driver identification and for the development of driver assistance systems.
|
|
| 7. |
- Solis Marcos, Ignacio, et al.
(author)
-
Performance of an Additional Task During Level 2 Automated Driving : An On-Road Study Comparing Drivers With and Without Experience With Partial Automation
- 2018
-
In: Human Factors. - : Sage Publications. - 0018-7208 .- 1547-8181. ; 60:6, s. 778-792
-
Journal article (peer-reviewed)abstract
- Objective: To investigate the influence of prior experience with Level 2 automation on additional task performance during manual and Level 2 partially automated driving.Background: Level 2 automation is now on the market, but its effects on driver behavior remain unclear. Based on previous studies, we could expect an increase in drivers’ engagement in secondary tasks during Level 2 automated driving, but it is yet unknown how drivers will integrate all the ongoing demands in such situations.Method: Twenty-one drivers (12 without, 9 with Level 2 automation experience) drove on a highway manually and with Level 2 automation (exemplified by Volvo Pilot Assist generation 2; PA2) while performing an additional task. In half of the conditions, the task could be interrupted (self-paced), and in the other half, it could not (system-paced). Drivers’ visual attention, additional task performance, and other compensatory strategies were analyzed.Results: Driving with PA2 led to decreased scores in the additional task and more visual attention to the dashboard. In the self-paced condition, all drivers looked more to the task and perceived a lower mental demand. The drivers experienced with PA2 used the system and the task more than the novice group and performed more overtakings.Conclusions: The additional task interfered more with Level 2 automation than with manual driving. The drivers, particularly the automation novice drivers, used some compensatory strategies.Applications: Automation designers need to consider these potential effects in the development of future automated systems.
|
|
| 8. |
- Victor, Trent, 1968, et al.
(author)
-
Automation Expectation Mismatch: Incorrect Prediction Despite Eyes on Threat and Hands on Wheel
- 2018
-
In: Human Factors. - : SAGE Publications. - 1547-8181 .- 0018-7208. ; 60:8, s. 1095-1116
-
Journal article (peer-reviewed)abstract
- Objective: The aim of this study was to understand how to secure driver supervision engagement and conflict intervention performance while using highly reliable (but not perfect) automation. Background: Securing driver engagement—by mitigating irony of automation (i.e., the better the automation, the less attention drivers will pay to traffic and the system, and the less capable they will be to resume control) and by communicating system limitations to avoid mental model misconceptions—is a major challenge in the human factors literature. Method: One hundred six drivers participated in three test-track experiments in which we studied driver intervention response to conflicts after driving highly reliable but supervised automation. After 30 min, a conflict occurred wherein the lead vehicle cut out of lane to reveal a conflict object in the form of either a stationary car or a garbage bag. Results: Supervision reminders effectively maintained drivers’ eyes on path and hands on wheel. However, neither these reminders nor explicit instructions on system limitations and supervision responsibilities prevented 28% (21/76) of drivers from crashing with their eyes on the conflict object (car or bag). Conclusion: The results uncover the important role of expectation mismatches, showing that a key component of driver engagement is cognitive (understanding the need for action), rather than purely visual (looking at the threat), or having hands on wheel. Application: Automation needs to be designed either so that it does not rely on the driver or so that the driver unmistakably understands that it is an assistance system that needs an active driver to lead and share control.
|
|
