bluuebunny/crossref_metadata_2025 huggingface dataset:
Development of an Ergonomic Waste Container for Hospitals
Authors: Padilla Rosa , Baltich Jennifer , Fathallah Fadi
Published: January 2012

The current waste container design at most hospitals, including the UC Davis Medical Center, requires an individual to raise the garbage bag up and out of the container, which involves shoulder flexion above the head and flexion at the waist for most individuals. Overuse injuries due to lifting are very common to the muscles of the shoulder and result in high costs for treating injured workers. The aim of this study was to design a new waste container that will limit the amount of shoulder and trunk flexion required to remove the garbage bags from the container. A waste container was developed, which rotates about two pins on each side to 30 and 45 degree angles from the upright position so that the bags can be removed without lifting them over your head. The degree of shoulder and trunk flexion for the new and old waste container was measured using electrogoniometers. The most important result was that the average degree of shoulder abduction decreased by about 9 degrees from the new bin at 30 degrees and 10 degrees to the new bin at 45 degrees. There also was a significant reduction in sagittal flexion between the old bin and the new bin. The reduction in the level of shoulder abduction and sagittal flexion with this new design may reduce the incidence of injury and improve working conditions for custodial staff in hospital environments.
Ergonomic Design in Hospital Beds: Comparison of Brake Pedal Design and Steering-assistance Features
Authors: Jia Bochen , Barker Linsey M. , Kim Sunwook , Agnew Michael J. , Nussbaum Maury A.
Published: January 2012

Transporting patients using a hospital bed is a common and often difficult task in a healthcare environment. The aim of this study was to compare the usability and physical demands of alternative bed design features associated with brake engagement and bed maneuvering tasks. Specifically, the brake system and steering-assistance features of two hospital beds were evaluated within a simulated healthcare work environment. Two sets of participants were recruited from the local student population and community. Task completion time, perceived usability of brake and steering-assistance features, hand forces, and trunk kinematics were measured during the braking and maneuvering tasks to assess the usability of the bed features and the physical demands likely placed on healthcare workers. With respect to brake design, a frontal brake (when bed side rails were down) was found to be significantly less efficient than a brake located at the side or at the foot-end of the bed. During in-room maneuvering tasks, the steering-assistance feature significantly reduced hand forces and increased perceived usability. Furthermore, patient mass significantly affected required hand forces. Regardless of the use of steering-assistance features, the physical demands observed in the present study might exceed recommended ergonomic guidelines. Therefore, to improve the ergonomic design of hospital beds in terms of healthcare workers' physical effort and work efficiency, it is recommended that further ergonomic assessments should be made regarding the usability of bed design features and future improvements.
Force-Exertion Postures with External Bracing in Industrial Tasks: Data from an Automotive Assembly Plant
Authors: Jones Monica L.H. , Kirshweng Rebecca L. , Armstrong Thomas J. , Reed Matthew P.
Published: January 2012

During one-handed tasks, individuals will often support their body mass using the contralateral hand or other body region. It is hypothesized that bracing postures are adopted to reduce and/or change the tasks demands, allowing the individual to assume a more optimal posture or reduce spinal loading. Accurate representation of such task postures is essential for accurate assessment of worker capability (Chaffin & Erig, 1991). It is especially critical given that the risk of injury is greatly increased when job strength requirements exceed worker capabilities (Chaffin, et al., 1978). Biomechanical analyses of supported or externally braced tasks are difficult to analyze because the upper body support is statically indeterminate. As an initial step to understanding bracing behaviors, a plant survey was conducted to investigate the prevalence of such bracing postures adopted during automotive assembly tasks. Video data from 436 occurrences of externally braced task postures from 20 automotive assembly operations were analyzed. Categorical analysis identified postural strategies associated with externally supported exertion tasks.
Box Weight or Lift Rate: Which Factor Matters More during Lifting?
Authors: Kotowski Susan E. , Davis Kermit G. , Marras William S.
Published: January 2012

Previous research has shown that lift rate and box weight are known to influence the risk of developing a low back disorder. However, when a given amount of material must be transferred there is little guidance as to the best combination of weight and lift rate in order to have the lowest risk of developing a back injury. The current study investigated combinations of lift rate and box weight when moving a given amount of material with respect to the impact on spinal loading, perceived exertion, and perceived risk of injury. The results show that there is an interaction between lift rate and box weight. There was a trade-off in loading cumulative and peak loading for both compression and shear loads which was dependent upon the weight and lift rate. Perceived exertion was influenced more by box weight than lift rate. Based on all the loading results, it is recommended that workers should under one of the following conditions: 4 or 8 lpm for 9.1 kg weight boxes and 12 lpm for the 4.5 kg weight boxes.
The Relationship between Mechanical Stiffness, Dynamic Strength and Static Strength following Eccentric or Concentric Activity
Authors: Chourasia Amrish O. , Sesto Mary E.
Published: January 2012

Workplace exertions can involve static, muscle lengthening (eccentric), or muscle shortening (concentric) exertions. The purpose of this study was to examine the relationship between mechanical stiffness, dynamic strength and static (isometric) strength following sub maximal eccentric or concentric exercise. Participants were randomly assigned to perform eccentric or concentric forearm supinations at 50% of isometric supination strength for 30 minutes. Mechanical stiffness, isometric and dynamic strength were measured prior, one hour after and 24 hours after exercise. Average mechanical stiffness decreased 31% (p < 0.05) after 24 hours for the eccentric group and decreased 16% (p > 0.05) for the concentric group. Average static strength in both groups recovered to within 2% of pre exercise levels for both groups after 24 hours. Average dynamic strength decreased 18% (p < 0.05) 24 hours after exercise for the eccentric group and increased 7% (p > 0.05) for the concentric group. Significant correlation (r = 0.664 to 0.832, p < 0.05) was observed between changes in mechanical stiffness and dynamic strength. Reductions in dynamic strength and mechanical stiffness persisted 24 hours after unaccustomed eccentric exertions but similar changes were not observed for static strength.
Information Everywhere: Exploring the Potential of the Mobile Web
Authors: Del Giudice Katherine
Published: January 2012

The World Wide Web has become a cornerstone of modern information retrieval. Easy and timely access to information is becoming crucial to many tasks we perform each day. The Web is also being increasingly used as a tool for communication and social network strengthening. The desire to be constantly connected to information and people is driving user adoption of the mobile Web, or the World Wide Web as accessed through mobile devices such as cell phones or PDAs. This panel will explore the potential of the mobile Web, examine the challenges present in designing information displays for mobile contexts, and consider future applications for this form of information retrieval.
Using the Analytic Hierarchical Process to Create a Single Usability Score for Website Interfaces
Authors: Shrestha Sav , Abdinnour-Helm Sue , Chaparro Barbara S.
Published: January 2012

We propose a new approach to create a single score metric to compare and rank the usability of website interfaces. The approach is based on the Analytic Hierarchy Process. We built the model and validated it using four usability studies, two of which are on a manufacturing firm website and the other two are on a service firm website. The results revealed a difference in domain between manufacturing and service. Still, this approach to creating a single score for usability is new in the literature for website evaluation and can help explain the ranking of website interfaces to non-experts. This is especially true for clients with the need to repeat website evaluations yearly or with clients who need a comparative analysis for their website against others in the same business. Future research is necessary to develop this approach further and validate it using a more comprehensive data set from an identical domain.
Naive Realism in Terrain Appreciation: Advanced Display Aids for Routing
Authors: Smallman Harvey S. , Cook Maia B. , Manes Daniel I. , Cowen Michael B.
Published: January 2012

Terrain appreciation must often be obtained from visual displays. However, users appear unaware that different terrain tasks are best supported by different terrain views. They express a blanket preference for high-fidelity realistic 3-D perspective views - a so-called Naïve Realism (Smallman & St. John, 2005). In last year's study, users preferred higher spatial fidelity than necessary for route-laying, when it was lower fidelity that unmasked avenues through terrain needed to lay well-concealed routes (Smallman, Cook, Manes & Cowen, 2007). Intriguingly, those of lower spatial ability persisted in a preference for high fidelity even after experience with the task. Here, we extend and refine last year's paradigm to test whether spatial ability makes one differentially sensitive to explicit task feedback by adding a display aid feedback manipulation between-participant. Feedback was available from an on-demand route “exposure envelope” visualization and a continuously-available overall route exposure score. Results revealed naïvely realistic intuitions - preferring high fidelity shaded perspective views when they never supported the best performance - on all tasks, unmitigated by spatial ability. However, after experience with the task, spatial ability contributed to savvier intuitions about the relative utility of the feedback aids, and better performance with the novel aids. Overall, feedback dramatically improved routing and made topo maps almost as good as low-fidelity shaded perspective views for routing, compensating for topo's usually observed inferiority for such shape understanding tasks. The study both refines the Naïve Realism theory and has applied implications for the design of terrain displays.
Bottom-up and Top-down Contributors to Pilot Perceptions of Display Clutter in Advanced Flight Deck Technologies
Authors: Alexander Amy L. , Stelzer Emily M. , Kim Sang-Hwan , Kaber David B.
Published: January 2012

Future concepts for the National Airspace System rely on technologies, such as synthetic and enhanced vision systems, to support flight efficiency associated with improved terrain and traffic awareness. While these technologies provide the pilot access to information not available with traditional flight instrumentation, the presentation of this additional information may serve to produce display clutter, thus inhibiting the processes and tasks they are designed to support. An experiment was conducted to assess pilot perceptions and identification of both bottom-up (data-driven) and top-down (knowledge-driven) contributing factors to display clutter. Results revealed the importance of both visual and information density (bottom-up and top-down factors, respectively) to the perception of clutter. Although added display elements provided pilots with critical flight information, pilots considered displays to be cluttered when the imposed visual density exceeded the information density required for specific flight tasks. These findings suggest that moderate levels of display clutter may be tolerable, to the extent that the information is relevant to the tasks at hand.
Cross-Talk between Altitude Changes and Speed Control during Simulated Low-Altitude Flight
Authors: Wotring Brian , Dyre Brian P. , Behr Joseph
Published: January 2012

Simulations of flight over a planar environment create an ambiguous optical stimulus in which changes in altitude can potentially induce inappropriate control of speed. Previous research has shown that changes in altitude produce changes in global optical flow rate that lead to erroneous judgments of speed and increased RMS error in speed control. However, from these studies it is unclear whether erroneous speed control was directly due to misperceiving changes in altitude as changes in speed or simply a response to more complex optical flow masking the optical effects of speed changes. Our experiment used a speed maintenance task during simulated flight over a planar surface to examine the effect of changes in altitude on control of speed. We found that power in participants' speed control input increased at the specific frequencies of the simulated altitude changes relative to power at those same frequencies when no altitude disturbance was present. These results clearly show that controllers respond to altitude changes as if they are changes in speed during simulated flight over a planar environment. Hence, the optical effects of altitude changes appear to be perceived as changes in speed and induce systematic errors in speed control.
Negative Acceleration and Adaptive Automation Approaches to Counter the Effect of Acceleration Induced Loss of Consciousness
Authors: Tripp Lloyd D. , Warm Joel S. , Matthews Gerald , Chiu Peter Y. , Bracken R. Bruce
Published: January 2012

Gravity-induced loss of consciousness (GLOC) is a major human factors problem facing fighter pilots today. A recent study by Tripp et al. (2006) reported that the GLOC episode consists of 24 sec of unconsciousness and confusion/disorientation followed by 55 sec in which performance efficiency is compromised. Hence, fighter pilots in the throes of GLOC can travel 12 miles while not in control of their aircraft. Using a centrifuge to simulate gravitational forces together with tracking and math tasks to simulate flight control and navigation, this study attacked the GLOC problem in two ways: (1) by employing negative acceleration following GLOC onset to decrease GLOC recovery time and (2) by assessing the utility of a of cerebral tissue oxygen saturation (rSO2) measure as a possible triggering mechanism for an adaptive automation recovery system. Negative acceleration had no significant effect on the duration of the GLOC episode. Declines in rSO2 from baseline pinpointed when pilots would cease active flight control and when GLOC would set in. Thus, the rSO2 measure may be of effective value as an adaptive automation GLOC recovery system trigger. The rSO2 measure also showed that loss of blood oxygen is not the sole factor underlying performance deficits in GLOC. Tissue oxygen saturation retuned to baseline levels shortly after the centrifuge came to a complete stop following GLOC onset but the performance deficits continued for 55 sec after rSO2 returned to baseline.

Cleared for Public Release Distribution Unlimited
Measuring the Workload of Sustained Attention: Further Evaluation of the Multiple Reources Questionnaire
Authors: Finomore Victor S. , Shaw Tyler H. , Warm Joel S. , Matthews Gerald , Riley Michael A. , Boles David B. , Weldon Dave
Published: January 2012

This study confirms and extends a recent finding by Finomore et al. (2006) that the Multiple Resources Questionnaire (MRQ; Boles & Adair, 2001) can be of effective value in assessing perceived mental workload in vigilance tasks. As in the earlier study, the MRQ was evaluated by comparing it against a standard measure of workload in vigilance research, the NASA-Task Load Index (NASA-TLX; Hart & Staveland, 1988), in its sensitivity to experimental factors known to influence task demand. The factors in this case were the sensory modality of signals and event rate. Both workload scales showed that the level of workload was substantial, and that workload was greater for the fast than slow event rate. The NASA-TLX indicated that workload was greater when monitoring visual than auditory stimuli. With the MRQ, the sensory modality of signals emerged as a moderator variable for event rate; the effects of event rate were restricted to visual signals. The MRQ also identified resource dimensions that were utilized in the vigilance tasks that are not included in the NASA-TLX. Thus, the MRQ exhibited the properties of sensitivity and diagnosticity characteristic of a valid workload scale (O'Donnell & Eggemeier, 1986).
Effects of Secondary Loading Task Modality on Attentional Reserve Capacity
Authors: Brill J. Christopher , Mouloua Mustapha , Gilson Richard D. , Rinalducci Edward J. , Kennedy Robert S.
Published: January 2012

The purpose of the present study was to use a newly-developed measure of reserve attentional capacity to evaluate unitary versus multiple resource theories of attention. Participants performed a primary visual monitoring task and were presented with visual, auditory, and tactile secondary loading tasks. The data indicate that participants maintained performance on the primary task, as instructed, and performed the secondary task with any remaining attentional reserve capacity. A significant difference was found on the basis of secondary task modality, wherein performance on the visual secondary task was significantly worse than that of secondary auditory and tactile tasks. This result was additionally supported by scores on a subjective workload questionnaire. Although the data do not preclude interpretation in terms of a unitary resource model, data trends offer potential support for a multiple resource model.
Combining Spatial and Temporal Task Demands: Effects on Performance, Workload, and Stress
Authors: Szalma J. L. , Thropp J. E. , Hancock P. A.
Published: January 2012

An experiment is described examining the effect of combining spatial and temporal task demands on performance, workload, and stress associated with perceptual discriminations at two levels of difficulty. The effect of intermittent bursts of white noise was also examined. According to the maximal adaptability model, the joint effects of task type, noise exposure, and discrimination difficulty should produce a performance decrement as well as increased perceived workload and stress. Although results conformed to expectation for task manipulation, intermittent white noise and discrimination difficulty did not have the interactive effect predicted according to the maximal adaptability model. Implications for future research are discussed.
The Effect of Driving Experience on Change Blindness at Intersections: Decision Accuracy and Eye Movement Results
Authors: Edwards Christopher J. , Caird Jeff K. , Chisholm Susan L.
Published: January 2012

To understand the differences between inexperienced and experienced driver visual behavior for hazard detection at intersections, twelve less experienced drivers aged 18 to 19 and twelve experienced drivers aged 35 to 48 were shown 36 complex intersection images using a modified flicker method. Twenty-four of these intersections contained a changing object that was a pedestrian, vehicle or a traffic control device. The remaining 12 intersections did not contain a changing object. Visual search was measured using a head mounted eye movement system and areas of interest were specified for each image to determine the foci of visual search. The time to view the flickering images affected turn decision accuracy. The pattern of results showed that less experienced drivers tended to fixate on other vehicles within the intersections, whereas experienced drivers fixated on lights and signs. The implications of the results on hazard perception are discussed.
Towards an Empirically Developed Scale for System Trust: Take Two
Authors: Spain Randall D. , Bustamante Ernesto A. , Bliss James P.
Published: January 2012

Research on human trust in automated systems has been frequently limited by the use of inappropriate and inaccurate scales of human-machine trust. An attempt is made here to validate a scale proposed by Jian, Bisantz, and Drury (2000) that measures trust and distrust in automated systems. Sixty participants completed a patient monitoring task with the aid of an imperfect signaling system. Confirmatory factor analyses were conducted using LISREL 8.0 to determine the best fitting measurement model. Chi-square difference tests indicated that the best fitting model was the 2-factor oblique model. These results suggest that when using the System Trust Scale, researchers should treat trust as a multi-dimensional construct comprising of two distinct, yet related, factors. Implications for future research and measurement development are discussed.
Discount Ratio Effect and Mental Accounting in Money Saving Decisions
Authors: Klein Alison K. , Wang X. T.
Published: January 2012

The discount ratio effect, a systematic devaluation of savings as the ratio of the present to discounted values decreases, was demonstrated in the classic “Jacket and Calculator” problem by Kahneman and Tversky (1984). The effect is a clear violation of economics principle of fungibility for money. A specific type of mental accounting is considered to be responsible for this effect (Kahneman & Tversky, 1984). Our recent study suggested that the discount ratio effect diminishes when savings are in the context of intertemporal choices (Wang, 2004). The present research further explored some antecedent conditions of the discount ratio effect, and examined reasons for participants' purchasing decisions. Results showed that interactions between ratio of savings and delay were not consistent but dependent on the content of the purchase (books vs. cell phones). Participants were more likely to spend effort on savings for hedonic purposes in high discount ratio conditions and for utilitarian purposes in low discount ratio conditions. Agreement ratings to mental accounting arguments revealed different patterns in delay and travel conditions.
The Effects of Mutual Inclusiveness between Captains and First Officers on Psychological Safety and Engagement in Flight Safety
Authors: Chang Su Wong , Lee Kyung Soo , Ham Seong Soo , Lee Sun Ah , Hahn Tae Kyung , Sohn Young Woo
Published: January 2012

This research aims at determining psychological elements that influence team coordination between a captain and a first officer in a commercial airline cockpit. It also examines how these elements interact between one another in different cultural settings. We propose that mutual inclusiveness of differential status enhances psychological safety and engagement in safety improvement efforts. Survey results based on 254 airline pilots suggest that status (captain, first officer) and mutual inclusiveness (openness between team members) influence psychological safety and mutual inclusiveness moderates the relationship between status and psychological safety. The results also suggest that psychological safety is positively associated with engagement in safety improvement efforts and also mediates the relationship between mutual inclusiveness and improvement efforts. This research provides insights into antecedents of fostering safety improvement efforts in airline crew teams in which cultural differences and professional hierarchy exist.
Workload Transitions in Driving
Authors: Morgan Justin F. , Smoker Timothy J. , Garcia Andre J. , Hancock Peter A.
Published: January 2012

Driver mental workload is an often studied concept, however less attention is given to the question of transitions in driver workload. Fourteen adult drivers completed a simulated driving task following a navigation system which would fail at certain intervals. Subjective measures of driver workload were taken and demonstrate that the recovery from a driving stressor is asymmetrical and time-delayed. Drivers' subjective ratings of workload remained high after the stressors were removed. Findings and implications are discussed.
A Meta-Analysis of the Effect of Time Pressure on Human Performance
Authors: Szalma J. A. , Hancock P. A. , Quinn S.
Published: January 2012

A quantitative review of time pressure effects on human performance was conducted. One-hundred-twenty-five references were identified that met selection criteria. These studies provided 827 effect sizes. Analyses revealed an overall small but detrimental effect of time pressure on performance. However, moderator analyses indicated that the effect of time pressure varied as a function of task type and the measure of performance (accuracy vs. speed). As expected, time pressure facilitated speed but impaired accuracy for both perceptual and cognitive tasks. Although there were few studies available for motor tasks, evidence from the available studies indicated that time pressure reduced speed. Accuracy data were inconclusive. Across all analyses there was evidence of substantial variability across studies, indicating that other moderating variables may influence the performance effects of time pressure.
Measurement Invariance of the Nasa TLX
Authors: Bustamante Ernesto A. , Spain Randall D.
Published: January 2012

Mental workload is one of the most important constructs of interests for Human Factors researchers. Adequately assessing the amount of mental workload that people experience while performing tasks under specific conditions is essential for the design of safe and efficient systems. Due to its ease of use, the NASA TLX has become the most widely used method of measuring mental workload. However, its psychometric properties are still questionable. The purpose of this study was to examine the extent of measurement invariance of the TLX and raise awareness in the Human Factors community. Two hundred participants reported the amount of mental workload they typically experience while driving in urban and rural areas and across the country. Results indicated that the TLX lacked scalar invariance, thereby biasing the estimation of mean scores and making the examination of mean differences misleading. These findings suggest that researchers should first examine the extent of measurement invariance of the TLX before they proceed to make inferences about mean differences in the amount of mental workload reported by participants under different conditions.
Uses of Eye Tracking Technology in Design
Authors: Medina Eliana , Cuddihy Elisabeth , Goldberg Eli , Ramey Judith A.
Published: January 2012

Eye tracking technology has caught the attention of designers who wish to better understand how users visually interact with products and technologies. Given the availability of eye tracking technologies, which are able to measure users' eye gaze on computer screens, designers and researchers can employ eye tracking to answer a very wide variety of questions about users' visual behavior, cognition, and visual attention strategies. Yet, commercial eye tracking software typically provides a limited number of out-of-the-box analysis tools for understanding the massive amount of data generated during eye tracking sessions. This poster (1) surveys the range of questions that people have successfully asked using eye tracking technology and (2) summarizes how raw eye tracking data is transformed into higher-level constructs that are more appropriate for analysis and the kinds of analysis that can be performed. The goal of this poster is to help designers make more informed decisions when considering the use of eye tracking to aid them in design.
Do you see what I see? Eye Tracking and Shared Mental Models
Authors: Feldman Moshe , Lum Heather C. , Sims Valerie K. , Smith-Jentsch Kimberly , Lagattuta Nicholas
Published: January 2012

Shared mental models of the team and task have been shown to facilitate better team processes (e.g. coordination) and performance. To this extent, more dynamic measures of mental model measures are needed to better understand how sharedness is through various team macrocognitive stages. This study investigated the relationship between eye patterns and mental model sharedness. Results indicate a positive relationship between mental model sharedness and eye fixation similarity. Implications for future research are discussed.
Attentional Asymmetries in Virtual Space
Authors: Heber Ines Ann , Siebertz Sarah , Wolter Marc , Kuhlen Torsten , Fimm Bruno
Published: January 2012

The present study investigated the influence of virtual depth on attentional asymmetries in healthy young participants (n = 20), by administering a variation of a luminance judgment task as well as a line bisection task in different depth locations (peripersonal, extrapersonal) within three-dimensional virtual space. Pseudoneglect was present in both tasks and depth locations with clear emphasis on peripersonal space. The results show highly significant attentional asymmetries in virtual space that are comparable to real space and suggest that Virtual Reality (VR) is an appropriate tool for assessing visuo-spatial attention in virtual space.
Improving Neutron Detection: Usability Analysis of Control Mechanisms and Control Orientations for Use in Hand-Held Devices
Authors: Herring Scarlett , Castillejos Pamela , Hallbeck M. Susan
Published: January 2012

This study was conducted to determine the best control mechanism for a hand-held neutron detector testing three control mechanisms (blister buttons, push-buttons and a single-axis rocker) and two control mechanism orientations (vertical and horizontal). A simple menu-selection task, based on the current neutron detector, was conducted to evaluate the prototypes and determine the most efficient combination of control mechanisms and handle shapes. The most efficient combination was based on the lowest error rate and movement time. The results of this investigation found support for the horizontally oriented controls. In addition, blister buttons were found to be the best control mechanism (lowest error) out of the three control mechanisms tested. Blister buttons should have a diameter of at least 1.3 cm and provide tactile feedback to the first responder in order to enhance user performance.
Highlighting Validity and Placement of Risk Information in Drug Manufacturers' Direct-to-Consumer Web Pages
Authors: Hicks Kevin E. , Wogalter Michael S.
Published: January 2012

Since the mid-1980s, direct-to-consumer (DTC) advertising has changed the way pharmaceutical companies market prescription medications. The Internet is a growing source of drug information and drug manufacturer's websites are, according to the U.S. Food and Drug Administration, a form DTC advertising. The current study examined the effects of colored highlighting validity (Valid, Invalid and No highlighting) and placement (Top, Middle and Bottom) of target risk keywords in manufacturers' DTC web pages affects response time and accuracy using two kinds of visual search tasks. The two tasks were the same except that in one a target was always present and in the other the target was either present or absent. The results indicate that valid highlighting significantly reduced response time and increased accuracy in both tasks. Overall, invalid highlighting was not significantly different compared to no highlighting for response time or accuracy in both tasks. Also, placement had a significant effect in both tasks. Top and middle placements showed significantly lower response time compared to placement at the bottom. Accuracy was less clear-cut, particularly in the target present/absent task where placement at the top yielded significantly less accurate responses compared to the middle and bottom. In general, the results showed that highlighting has benefits when the sought information is validly highlighted, but there is virtually no cost when non-target information is highlighted instead, excepting the one instance noted above. Implications for potential application of highlighting and placement of risk information and for future research are discussed.
The Utility of Brief, On-Product Instructional Labels for a Fall Arrest Restraint Device
Authors: Pollack-Nelson C. , Sutherland M. , Lemonds J.
Published: January 2012

Fall arrest restraint devices for hunters are sometimes confusing to assemble due to the similarity of components; yet erroneous application can prove fatal. While assembly instructions are typically provided, they may not be available at the time of use. This study investigated the utility of adding brief, on-product instructional labels to a fall arrest restraint device. It was hypothesized that the addition of such labels would increase the rate of correct assembly over unlabeled restraints, and be about as effective as restraints provided with full instructions. Fifty-nine subjects were randomly assigned to one of three groups: (1) Restraint Only; (2) Restraint + Labels; (3) Restraint + Instructions. Labeled restraints produced more correct assemblies than unlabeled restraints; however, this finding was non-significant. While labels facilitated one aspect of assembly, they did not lead to improved overall assembly relative to restraints provided with instructions. Those receiving instructions performed significantly better than the other two groups. Many subjects receiving instructions were observed to rely largely on illustrations, rather than text. Results suggest that for products where assembly is non-intuitive, brief on-product identification labels may not be sufficient to guide proper assembly. Further, given that some consumers will not consult instructions or instructions may become separated from the product, manufacturers should strive toward intuitive designs.
Analysis of Australian and UK Rail Incidents and Accidents using Retrospective TRACEr Lite for Train Drivers
Authors: Baysari Melissa T. , McIntosh Andrew S. , Wilson John R.
Published: January 2012

Nineteen Australian safety investigation reports and 13 UK safety reports were reviewed and a human error identification technique (the Technique for the Retrospective and Predictive Analysis of Cognitive Errors: TRACEr-rail version) adopted as a means of identifying and classifying errors associated with rail incidents and accidents. In the Australian sample, it was revealed that most driver errors occurred when drivers were driving or stopping their train and that these errors consistently resulted in two consequences: speeding and signals passed at danger (SPADs). In the UK, errors occurred while drivers were performing a whole range of tasks, including driving, stopping, train assembly, and failed train operations. In Australia, most ‘train driving errors’ were ‘violations’ while most ‘train stopping errors’ were errors of ‘perception’. In the UK, a more varied range of errors was observed. Overall, the TRACEr-rail framework proved useful in categorizing driver errors from existing investigation reports and in highlighting recurring errors associated with incidents and accidents. However, the tool appeared to neglect some organizational factors contributing to driver error, and, preliminary inter-rater reliability testing revealed that some category descriptions may require further refinement. Future work will aim to develop a more Australian-friendly and reliable version of TRACEr for use in Australian rail.
Evaluation of the Hazards due to the Misunderstanding of Patient Medication Information Sheets
Authors: Kalsher Michael J. , Kaplan Charlotte , Fisher James
Published: January 2012

The U.S. Food and Drug Administration (FDA) mandates that all pharmacies provide customers with patient medication instruction (PMI) when distributing new prescription drugs. The information sheets describe instructions on proper usage and possible hazardous effects of the drug. The PMI is recommended to be written at a 6th grade reading level. Previous research has shown that the material found on patient medication instructions is written above the 6th grade reading level and that comprehension is directly correlated with reading and education levels. This study builds on previous work by showing that error rates, even among participants with college level reading skills, remains unacceptably high and that error rates are highest when the misunderstanding of an instruction is likely to cause greater harm.
An Investigation of the Impact of Fatigue and Aging on the Performance of Spatially Constrained Assembly Tasks Commonly Found in the Construction Industry
Authors: Mehta Ranjana , Agnew Michael J.
Published: January 2012

The goal of this study was to investigate the effects of fatigue and aging on the performance of spatially constrained drilling tasks that are observed within the construction industry. Eight younger (18–35 years) and eight older (45–60 years) participants were selected from the local community. Participants were presented with two conditions of localized muscle fatigue in the anterior musculature of the shoulder (No Fatigue and a Fatigue condition). During each condition, participants completed a series of drilling tasks at three levels of task difficulty; as defined by the spatial arrangement of the fasteners. The dependent variables; task completion time, error rate and muscle activation patterns (shoulder APDF and coactivity indices of the upper and lower arm), were measured using observations and electromyography of the muscles of the upper extremity. The presence of localized shoulder fatigue significantly reduced task completion times for both age groups at all levels of task difficulty. Further, error rate was higher for the younger age group in the fatigue condition compared to the no fatigue condition; no such differences were seen for the older subjects. Muscle activity decreased for the anterior deltoid in the fatigue condition, and concurrent increases were observed in the coactivity indices of the upper and the lower arm musculature.
How Individual Differences and Task Load May Affect Feedback Use When Learning a New Task
Authors: Kelley Christopher M. , McLaughlin Anne Collins
Published: January 2012

The literature shows mixed findings regarding how much feedback is best for learning a task (cf. van Merriënboer & Sweller, 2005; Schmidt & Bjork, 1992). One model describes feedback specificity as resource dependent (McLaughlin, 2006). The current study provided a test of that model by including learners with high and low working memory on a managerial decision making task. The full study is ongoing, but pilot data indicate those with lower working memory capacity may not be able to fully utilize feedback they are given. Results are discussed and implications for future research provided.
Seeing Pedestrians at Night: Visual Clutter Does Not Mask Biological Motion
Authors: Tyrrell Richard A. , Wood Joanne M. , Chaparro Alex , Carberry Trent P. , Chu Byoung-Sun , Marszalek Ralph P.
Published: January 2012

The phenomenon of biological motion – placing reflective markers on a pedestrians' major joints – has been shown to make pedestrians more conspicuous to drivers at night. However most relevant studies have been conducted in scenarios relatively free of visual clutter. Because clutter could mask the perception of biological motion, we tested whether extraneous points of light degrade drivers' ability to detect pedestrians. Twelve younger and 12 older volunteers drove along a closed road at night and indicated whenever they saw a pedestrian. A pedestrian walked in place wearing all black clothing alone or with retroreflective markings in one of four configurations. On half of the trials the pedestrian was surrounded by reflective cones and posts (clutter). Clothing configuration dramatically influenced conspicuity. The pedestrian was usually not seen when he wore no reflective markings or when he wore a reflective vest. But when he wore reflectors on his ankles and wrists the younger and older drivers responded at mean distances of 285 m and 141 m, respectively. Importantly, the presence of visual clutter did not significantly influence performance. These results confirm that biological motion can enhance the conspicuity of pedestrians; this effect is robust to the presence of visual clutter.
A Procedure for Developing Warning Message Prioritization Rules in Integrated Collision Warning Systems for Heavy Trucks
Authors: Richard Christian M. , Campbell John L. , James L Brown
Published: January 2012

This paper presents the results of an effort to create a comprehensive and systematic procedure for developing warning message prioritization rules in integrated Collision Warning Systems (CWS) for heavy trucks. Although there are existing guidelines and even ISO standards for accomplishing this, in practice these sources are inadequate because they are not designed to handle the high degree of complexity and large number of warning conflict permutations that occur in integrated systems that have multiple subsystems, each with multiple warning levels. This paper presents a procedure that expands on existing sources, but has the level of detail and structured tools necessary to represent the variety of information that requires consideration when making decisions about the prioritization of warning messages.
Developing Complex Crash Warning Simulations for Human Factors Evaluations
Authors: Green Paul
Published: January 2012

In traditional vehicle warning experiments, each subject sees each warning once, and warning comparisons are between subjects, a very inefficient approach. Driving simulator experiments for the recent RDCW and IVBSS projects used within-subjects designs, with each subject responding to a warning about once per minute. That presentation rate and the scenarios developed seemed reasonable to independent human factors experts who experienced them and the simulations were often able to distinguish differences of interest.

What made the simulations reasonable was (1) the use of real world crash data as a starting point for scenarios, (2) the large number of scenarios employed, each of which had both normal and crash-related outcomes, (3) the presence of three to five vehicles in the scene, each requiring the driver's attention, (4) the use of real on-road data to select gaps, closing rates, etc., and (5) work-arounds when scenarios did not go according to plan. For developing and communicating the plan, option tables and storyboards were particularly useful.
Non-conscious Activation of an Elderly Stereotype Leads to Safer Driving Behavior
Authors: Branaghan Russell J. , Gray Rob
Published: January 2012

Under the guise of evaluating a head-up display in a driving simulator, participants completed scrambled sentence tasks (while waiting at stop signs) designed to prime an elderly stereotype. Driving speed and driving time between stop signs in this Elderly Stereotype condition were compared to a Control condition in which age non-specific words were substituted for elderly stereotyped words. Participants had a lower maximum speed and longer driving time in the Elderly Stereotype condition than in the Control condition. This effect was obtained even though the participants were completely unaware of the theme in the experimental condition. Theoretical, as well as applied implications are discussed.
Sensory-Perceptual Objective Task (SPOT) Taxonomy: A Task Analysis Tool
Authors: Champney Roberto K. , Carroll Meredith , Milham Laura , Hale Kelly
Published: January 2012

Task Analyses serve multiple purposes in system design, yet even with the resource intensive nature of such processes, further insight is still needed for the design of multi-modal systems. A Sensory Task Analysis (STA) allows a very granular level task decomposition into sensory information and interaction capability requirements that allows the determination of how individuals in the domain gather information as well as act upon this information in the operational environment. To complete this, however, knowledge of both the domain task and human information processing theory is required. Herein is presented a sensory-perceptual task taxonomy, a task analysis tool that facilitates the decomposition of domain tasks into generalizable sensory perceptual and response task types that greatly facilitates this process. This paper discusses the development and components that make up this taxonomy and presents a proof of concept example of how it may be used in an operational military domain. A discussion of potential applications and how this taxonomy fits within a tool to define optimal system fidelity requirements is also presented.
Incorporating Reverse Engineering and Competitive Analysis Techniques into the System Design Process: A JTRS HMS Case Study
Authors: Savage-Knepshield Pamela A.
Published: January 2012

This case study highlights activities performed during a system design effort undertaken by the Joint Tactical Radio System Handheld, Manpack and Small Form Fit Program. A modified waterfall model comprised of three cyclic, yet overlapping phases (observation, visualization, and evaluation) provided structure for the iterative, Warfighter-centric system design process. Through analyses of existing commercial and military mobile handheld devices, the design team identified best practices that were worthy of emulation, practices that should be avoided, and practices that warranted further research. Design intelligence gleaned through the application of reverse engineering and competitive analysis techniques was used to guide interview question development and discussion during subject matter expert interviews, to narrow the scope of design options for test and evaluation, and to provide design direction. Insights gained from applying these techniques to system design and evaluation and the impact that their use had on the system's design are discussed.
Eliciting Expectations to Develop Trust in Systems
Authors: Miller Janet E. , Batchelor Cheryl , Perkins LeeAnn
Published: January 2012

A schema is a mental structure that represents some aspect of the world. Schemata are used to organize current knowledge of the world and to provide a framework for future understanding. When a new situation or capability is encountered, a schema is brought up for comparison and then the schema is altered as necessary. Expectations are part of the mental schema and can determine the fate of a relationship, be the relationship human-human or human-other. As complex socio-technical systems become more ubiquitous and as events become more dynamic, the ‘human-other’ relationship is often human-automation and the automation is a decision support system. Understanding the expectations of the intended user of a capability helps the system designer and developer address those expectations which helps instill trust in the developed capability. While much has been written on trust, understanding expectations that underlie trust has been neglected. This paper will discuss three methods explored to directly elicit expectations thereby enhancing initial trust in human-decision support systems.
Visualization Design Using an Integrated Joint Cognitive System Development Methodology
Authors: Hale Christopher R.
Published: January 2012

We describe the development of a visualization-based decision support system for operational effects assessment. The system was developed using the Integrated Methodology for Joint Cognitive Systems (IMJCS). The IMJCS is designed to integrate cognitive system engineering (CSE) throughout system development by addressing four areas: Content, communication, risk management and traceability. Development phases in IMJCS will be presented as context within which the development of the visualization system was carried out. The IMJCS is distinguished from other approaches to human-centered design in that it is designed to integrate into existing system engineering processes and to make contributions throughout the entire system engineering development cycle.