bluuebunny/crossref_metadata_2025 huggingface dataset:
Effects of Long Duration and Repeated Exposures in an Immersive Virtual Envionment on Postural Stability
Authors: Duh Henry Been-Lirn , Harm Deborah L. , Parker Donald E.
Published: January 2012

Postural disturbance following virtual environment (VE) exposure has been reported in many studies. Some suggest that postural disturbance could be a pre-cursor of or highly related to simulator sickness (SS). Few studies have addressed long duration exposure and multi-sessions in SS and postural disturbance. This study investigated effects of long duration and repeated exposure to an immersive VE on postural disturbance. The results suggested larger postural disturbance 24 hours and 48 hours after the first VE exposure. However, differences between postural disturbance magnitudes pre- and post- exposure within a day decreased after 48 hours. Differential effects were associated with different postural stances were also found. Suggestions for further research are addressed.
Evaluation of Force Feedback Steering in a Fixed Based Driving Simulator
Authors: Mourant Ronald R. , Sadhu Praveen
Published: January 2012

Eight participants drove a fixed base simulator using both spring-loaded and force feedback steering wheels. Their route included curves of 100, 200 and 300 radii of curvature, and two freeway style exit ramps that were sloped, banked and, had changing radii of curvature. Both mean and variance of lane position were calculated. There were no differences in terms of mean and variance of lane position between the steering wheels when driving on straight road segments. Lane position variance was significantly greater when driving on the 100 meter curves then when driving of the 200 and 300 meter curves. Drivers “hugged” left hand curves more when using the force feedback steering wheel as indicated by their average lane position being significantly more to the left. On the two right hand exit ramps, drivers drove significantly more to the left when using the force feedback steering wheel. Subjects rated the force feedback steering wheel higher in terms of realism, maneuverability, and vehicle control on a post-experiment questionnaire.
Training in a Virtual Stereoscopic Environment
Authors: Mourant Ronald R. , Parsi Lily
Published: January 2012

This study investigated transfer-of-training for a pick-and-place task in monoscopic, stereoscopic, and real-world environments. Ten training trials were given to 30 subjects in the three environments (10 subjects each). The averages of task completion time in the stereoscopic and real-world environments were less than those in the monoscopic environment. In a post-training real-world trial, there were no differences due to the training environment (including another group of 10 subjects who received no training). Subjects, who had training in the stereoscopic or real-world environments, were more accurate in the placement of cans at near targets than those who received monoscopic or no training. Thus training in a virtual stereoscopic environment was beneficial in terms of task accuracy. The effectiveness of virtual environments may continue to improve as advances in computer hardware enable higher resolution presentations and reduce system lags.
An Approach to Modeling Error in Air-Midas Using Contextual Control Model
Authors: Verma Savita A. , Corker Kevin , Jadhav Amit
Published: January 2012

Predictability of the possible avenues of human error is important for designing error recovery mechanisms in systems' interfaces. Our approach for modeling errors during the taxiing and pre-flight phase, involves using Hollnagel's (1993) Contextual Control Model (CoCoM). Hollnagel postulates that changes in the human's operational context make her switch control modes or cognitive strategies. Previously, Verma & Corker (2002) encoded rules to implement CoCoM for Air Traffic Controllers (ATCo) in the Air-MIDAS (Man-Machine Integrated Design and Analysis System) architecture. They defined the operational context as the number of simultaneous goals and the event horizon time required to successfully complete those goals, and also encoded behavior associated with three types of cognitive strategies- unplanned, tactical, and strategic. In this study, new sets of rules are being coded for the pilots, such mat changes in the context will cause the simulated operator to change cognitive strategies. The dependent variables of interest are cognitive strategies used by pilot-agents, workload, status of tasks (completed, aborted, working), and consequences of errors performed.
The Impact of Automation Use on the Mental Model: Findings from the Air Traffic Control Domain
Authors: Nunes Ashley
Published: January 2012

The ‘Free Flight’ (FF) concept has been proposed as a means of reducing delay in the airspace system. However, concerns over lapses in a controller's situation awareness as a result of FF implementation have prompted an influx of new technologies aimed at helping controllers more effectively predict the future trajectories of aircraft thereby preserving situation awareness. Such aids are based on the principle of direct visualization, whereby future system states are presented without providing adequate information to the user as to how these states were generated. Usage of aids that employ this design principle can have adverse effects on the mental model given that the user is not forced to extensively think about the processes governing the prediction. Drawing on the results from an empirical study in the air traffic control domain, evidence of this concern is presented and it is argued that caution must be exercised when introducing these aids, given the possibility that such usage may compromise a controller's ability to problem-solve and acquire knowledge.
Effects of Spatial Intercoms and Active Noise Reduction Headsets on Speech Intelligibility in an AWACS Environment
Authors: Bolia Robert S.
Published: January 2012

An experiment was conducted aboard an E-3 Airborne Warning and Control System aircraft to assess the ability of spatial intercoms and active noise reduction (ANR) headsets to improve communications effectiveness for air battle managers. Eleven male participants completed four blocks of data collection using the Coordinate Response Measure under factorial combinations of spatialization, ANR, and target phrase location. Results indicate that the use of a spatial intercom led to greater intelligibility, and that ANR improved intelligibility only when used in combination with a spatial intercom. These results are discussed in terms of their applicability to current and future USAF application domains.
Conflict Detection with Cockpit Display of Traffic Information: What is it, What has Been Found, and What Needs to be Done?
Authors: Xu Xidong
Published: January 2012

A task analysis is conducted for conflict detection relying on traffic information depicted on a cockpit display of traffic information (CDTI). The task can be performed in a dichotomous way (i.e., the judgment of either a conflict or not). Or optimally the conflict risk can be estimated based on continuous measures. Three such measures are identified, namely, the distance at the closest passage (DCP), the orientation at the closest passage (OCP), and the time at the closest passage (TCP). A literature review examines the factors that influence performance on conflict detection. It is shown that there are limited numbers of studies that have addressed the issue of conflict detection with the CDTI. Finally, given the CDTFs vital role in the free flight environment, it is recommended that the conflict risk be defined by the continuous measures, that effects of various factors on conflict detection performance be examined, and that ways be sought to improve human performance with the aid of automation.
Experimental Investigation of Predictive Probabilistic and Temporal Conflict Avoidance Displays
Authors: Telner Jason , Milgram Paul , Williamson Alexander R.
Published: January 2012

Numerous automated systems are currently in use to assist controllers during air and naval traffic management. However, inferring the future intentions and courses of numerous aircraft or ships at various points in time remains problematic due to a variety of control disturbances. In this paper, a new graphical display concept was evaluated. This display concept provides predictive information about the time, location, and probability of potential traffic conflicts in the form of topological contour displays that were superimposed onto conventional traffic information. Performances on two formats of the new graphical display were compared to a conventional display that does not present predictive traffic information. Participants in the study engaged in a ship control collision avoidance task by performing a series of ship manoeuvres to minimize the danger levels of potential collisions. Although the results of the study are pending, it is hypothesized that the new graphical displays will assist participants in making improved manoeuvring decisions to avoid potential conflicts compared to the conventional display.
Evaluation of an Exocentric Surface Guidance Display
Authors: Roefs F.D. , Theunissen E. , Koeners G.J.M.
Published: January 2012

The topic of this study was an experimental display system consisting of a taxi-guidance display (TD) and a navigation display (ND). The main purpose of the TD is supporting local guidance, whereas the ND mainly supports global awareness. Two issues have been addressed: (1) ‘During taxiing, do pilots in fact use the TD for local guidance and the ND for global awareness?’ and (2) ‘What are the optimal parameter values for the TD?’. Based on recorded eye movements the first question can be answered affirmatively. Concerning the second issue it is concluded that the used reference parameter values are (close to) optimal. This is based on the parameter values selected by the participants and subjective measures.
Bridging the Gap Between Cognitive Work Analysis and Ecological Interface Design
Authors: Jamieson Greg A.
Published: January 2012

The Cognitive Work Analysis and Ecological Interface Design frameworks have garnered a great deal of attention in recent years. The former is used to analyze a complex work domain to identify the behavior-shaping constraints imposed by the work domain, control tasks, strategies, operator competencies, and socio-organizational factors. The latter informs the design of operator interfaces for complex systems. Although the two frameworks overlap, a gap remains between the analysis and design stages. This article shows one path across that gap. Aspects of both frameworks were applied to the design of an ecological interface for a petrochemical process. We discuss how the project was completed under realistic time and budget constraints, review several unanticipated obstacles that we encountered, and relate design examples to help overcome the gap between analysis and design.
Applying Decision-Centered Design to Damage Control for the Navy
Authors: Miller Thomas E. , Stanard Terry W. , Wiggins Sterling L.
Published: January 2012

Decision-Centered Design (DCD) was created so that the users of information technology (IT) have an advocate in the design cycle. DCD was created to increase the value of IT for the decision maker. It is a cognitive engineering approach to design that uncovers and models the cognitive expertise of users and conveys these insights to IT developers. DCD ensures that cognitive challenges are addressed in IT designs so that cognitive performance is improved. Other cognitive enginering approaches share these same goals, but DCD also has principles and processes that other cognitive engineering approaches may not share. This paper will use a Damage Control decision support system to illustrate the application of DCD.
Imperfect Automation in Aviation Traffic Alerts: A Review of Conflict Detection Algorithms and Their Implications for Human Factors Research
Authors: Thomas Lisa C. , Wickens Christopher D. , Rantanen Esa M.
Published: January 2012

Automated warning and alert devices such as airborne collision avoidance systems (ACASs) represent a class of automation that is often found to be imperfect. The imperfections can be expressed as the number of false alarms or missed events. Most ACASs are constructed with a bias to prevent misses (which may have catastrophic consequences) and therefore, coupled with a low base-rate of conflict events, create high false alarm rates. In this paper, we review the adequacy of various CDTI warning algorithms that have been proposed and tested in addressing the false alarm issue, and the potential for multiple levels of alerting to mitigate the effects of false alarms on trust and reliance on the CDTI. We suggest new directions for future research, including evaluating the effects of false alarm rates on pilots' use of the CDTI, determining what strategies may enhance pilot tolerance of false alarms, and investigating the use of CDTI in conjunction with air traffic controllers.
Applying Ecological Interface Design to the Driving Domain: The Results of an Abstraction Hierarchy Analysis
Authors: Stoner Heather A. , Wiese Emily E. , Lee John D.
Published: January 2012

Ecological interface design (EID) has been successfully applied in the domains of aviation, process control, and medicine. Until now, it has not been applied to the driving domain. This paper describes the results of applying the first step of EID, the abstraction hierarchy (AH) analysis, to the driving domain and then highlights key methodological differences. Key differences include heterogeneity at the level of functional purpose level, as well as the emergent domain constraints in which the other drivers define key work domain constraints. It is hoped that the information requirements identified here will help drivers form better mental models of driver support system (DSS) functions and assist in appropriate calibration of trust in these systems. This analysis demonstrates the generality of the AH analysis and provides an example that is substantially different from previous applications.
Authority in Adaptive Automation Applied to Various Stages of Human-Machine System Information Processing
Authors: Clamann Michael P. , Kaber David B.
Published: January 2012

The goal of this study was to assess the performance and workload effects of applying adaptive automation (AA) to four stages of human-machine system information processing (information acquisition, information analysis, decision-making, and action implementation) and facilitating dynamic function allocations (DFAs) through two levels of computer authority (suggestion and mandate). The research was to provide insight into any interaction between these aspects of AA design. It was hypothesized that higher level automation, such as information analysis and decision making, would be more compatible with computer mandated allocations, while lower levels, such as information acquisition and action implementation, would be more effective under partial human control (computer suggestion and human veto). Results demonstrated that the effectiveness of AA is dependent upon both the type of automation presented to an operator and the type of invocation authority designed into the system. Performance with AA of information acquisition was superior to performance under decision automation. When using automated assistance, human acceptance of computer suggestions was superior to computer mandates. The results of this study may serve as an applicable guide for AA design in future complex systems.
Ecological Interface Design for Network Management
Authors: Duez Pierre P. , Vicente Kim J.
Published: January 2012

This paper describes an experimental investigation of Ecological Interface Design (EID) in computer network management. The constant potential for the addition and removal of devices, as well as change of configurations, makes this work domain more fluid than those previously studied under EID. Two interfaces were created for the University of Toronto campus network consisting of 220 nodes: a P interface based on existing design practices which presented primarily physical information and a P+F interface based on EID which presented both physical and functional information identified by an abstraction hierarchy analysis. Participants were required to use one of the two interfaces to detect and diagnose faults or disturbances in the network in real-time. Network size and fault load were both manipulated as within-participants variables. The P+F interface led to faster detection times, improved rates of detection under higher fault loads, and more accurate diagnoses under higher fault loads. These results suggest that the EID framework may lead to more robust monitoring in computer network management compared to existing interfaces.
Usability Magnitude Estimation
Authors: McGee Mick
Published: January 2012

Magnitude estimation is a measurement method that is very useful for measuring multi-faceted constructs that do not have a physical analog (e.g., usability) and are produced from multidimensional stimuli (e.g., user interfaces). Traditional usability metrics have shown limitations in usefulness and validity. Usability magnitude estimation is an assessment method whereby participants assign usability ‘values’ to tasks, conditions, or other user interface targets according to ratio-based number assignments. The resultant ratio-scale data is appropriate for parametric statistical analysis. This method has been used successfully in a variety of usability activities at Oracle. It has proven to be efficient, sensitive, and highly effective for comparisons using usability as a differentiator.
Facilitating Database Queries: Graphical versus Numeric Preview
Authors: Goldberg Joseph H.
Published: January 2012

Numeric query preview was compared to graphical preview for constructing ad-hoc database queries in a usability study. The overall objective was to provide evidence to make design recommendations for a future software prototype. Based upon an earlier filter/flow graphical prototype, a visual query builder was developed to enable end users with little pre-existing knowledge to graphically construct complex database queries containing multiple Boolean operators. Usability evaluation was conducted with 12 users each generating 12 queries. Overall query completion rates were 83%, affirming the usability of this prototype query builder. Numeric preview allowed faster query construction than visual preview for complex queries, but visual preview may have promoted increased verification of constructed queries. Participants were likely able to use and interpret numeric preview information more readily than graphical preview information. While further studies are needed, numeric query preview, possibly combined with visual preview, is recommended for future prototypes.
Middle School Students who use Computers
Authors: Jacobs Karen
Published: January 2012

In recent years, there has been an increasing concern over the association between interactive media, such as computers and video games and reports of aches and pains in users. It is suggested that the physical set-up and individual styles of using interactive media has an influence over this discomfort. As children grow up, they will interact and use interactive media throughout most of their life. Healthy interactive media techniques may be vital to preventing/reducing the incidence of discomfort/pain associated with interactive media. This research paper will describe a study, which has collected health and comfort data on the incidence and prevalence of computer-related musculoskeletal discomfort/pain among 6th and 7th grade students in three middle schools in New England.
Comparison of Mouse, Touchpad and Multitouch Input Technologies
Authors: Shanis Jenna M. , Hedge Alan
Published: January 2012

Twelve subjects used fixed-angle split keyboards with a conventional mouse, an integrated touchpad, or an integrated MultiTouch surface. Three tasks were tested in each condition: data entry, text editing and cursor positioning. Wrist posture, performance (speed, errors) and subjective ratings were recorded. Results showed that mouse use was fastest for data entry, text editing tasks, and cursor positioning. MultiTouch was faster than the touchpad for cursor positioning, but slower for data entry and text editing. The mouse was rated as easiest to use. MultiTouch and the mouse were rated as more comfortable than the touchpad. There was marginally less wrist extension with use of the MultiTouch or the mouse than with use of the touchpad. Familiarity with keyboard and mouse use may have played a substantial role in the findings.
An Immersive Workstation Design Tool Using Three-Dimensional Anthropometric Data
Authors: Cerney Melinda M. , Vance Judy M. , Duncan Jerry R.
Published: January 2012

With the recent completion of the Civilian American and European Surface Anthropometry Resource (CAESAR), a comprehensive set of three-dimensional anthropometric data has been made available to the design community. This paper presents the development of a virtual reality tool which makes use of three-dimensional CAESAR data in a fully-immersive, virtual reality (VR) environment. This advanced operator workstation design tool enables design decisions to be made in a three-dimensional setting, allowing accurate visualization of relationships among human landmark data and workstation geometry. Methods for filtering and selecting data are presented. In addition, the utilization of landmark relationships specified by 3D data in an immersive, 3D design space are examined. The rationale, development, and implementation of this advanced operator workstation design tool are also presented.
A Survey of Learning Styles of Engineering Students
Authors: Ashford Terresa S. , Shehab Randa L. , Rhoads Teri Reed , Court Mary C.
Published: January 2012

This study examined the learning styles of engineering students using the Index of Learning Styles (ILS) developed by Soloman and Felder (Soloman & Felder, 2002), the Cognitive Styles Analysis (CSA) developed by Riding (Riding, 1991), and the Learning Style Inventory (LSI) developed by Kolb (Kolb, 1993). Thirty-five graduate and thirty-six undergraduate engineering students took each of the assessments. There was a strong preference for the visual category on the ILS, but an even split for the imagery/verbal dimension on the CSA. Scores were also evenly split on the active/reflective and sequential/global dimensions on the ILS. Another strong preference was seen for the analytic category on the CSA. On the LSI, most students' scores indicated a preference for the convergent category and no student scores were in the divergent category. An overview of each of the instruments as well as a summary of student learning needs for each of the dimensions is presented.
Relevance of the User Action Framework and Heuristics to E-Learning
Authors: Guarascio-Howard Linda , Walton Robin D. , Andre Terence S.
Published: January 2012

Electronic learning, or e-learning, uses the power and flexibility of the Internet and CD-ROM delivery systems to provide online instructional content. In this paper, we examine two usability inspection methods, the User Action Framework (UAF) developed by Andre, Hartson, Belz, & McCreary (2001) and heuristics developed by Jakob Nielsen (1994). Although not specifically designed for e-learning, both methods can be adapted to evaluate e-learning environments. The UAF provides a hierarchical structure and a framework for the systematic examination of usability issues. Heuristics provide guiding principles for evaluating user interfaces. While both inspection methods lend themselves to evaluating e-learning interfaces, we believe the UAF to be a more complete method for addressing e-learning usability issues.
Designing Cues for Recreational Parks to Support Wayfinding Behaviors
Authors: Soh Boon Kee , Smith-Jackson Tonya L.
Published: January 2012

Environmental landmarks are required for effective wayfinding when using maps, but landmarks such as signs are not always designed on the basis of human factors principles. This study was designed to investigate map design guidelines, wayfinding behaviors, and environmental cues that affect wayfinding. Thirty-six participants hiked on a designated trail in an outdoor park using the think aloud method. Observational and interview data were collected to examine how the participants interacted with the environment when using maps. The results showed that man-made features such as signage were useful in aiding wayfinding, but other geographical features of the environment were also used to support wayfinding. Recommendations for sign design and placement are discussed.
Compensability of Workers' Compensation Claims for Work-Related Musculoskeletal Disorders (WRMDS) Using Logistic Regression: An Empirical Study of an Appliance Manufacturer
Authors: Hinton-Hudson Veronica , Karwowski Waldemar
Published: January 2012

Over 6500 workers' compensation claims, initiated in 1993–1996 and closed by March 1997, in a population-based study of appliance manufacturing employees were evaluated. The result of statistical analysis (Chi-square test) disproves the hypothesis of no association between WRMDs and workers' compensation claim (compensability) outcome. In addition, a mathematical relationship between work-related musculoskeletal disorders and workers' compensation claim outcomes was developed using the logistic regression modeling. The results revealed that individuals with a WRMD type injury are 2.55 times more likely than an individual without a WRMD to be compensated. Other variables proving to be significant were tool use, being on restricted duty, and straining. The results have important implications for areas to target for prevention and ergonomic intervention among workers, particularly for return-to-work programs and workers' compensation cost reduction.
Cognitive Ability Correlates of Performance on a Team Task
Authors: Bell Brian G. , Cooke Nancy J.
Published: January 2012

This study examined the relationship between two cognitive ability measures, Grade Point Average (GPA) and verbal working memory capacity, and performance on a team task. Forty 3-person teams of students voluntarily participated in two experiments that required three team members to maneuver a simulated Uninhabited Air Vehicle (UAV) to take reconnaissance photos. Each of the team members assumed a different role with unique responsibilities. Low workload missions required that participants take 9 photos of various targets, whereas high workload missions required 20 photos and involved additional route constraints. The high workload manipulation produced significant reductions in team performance and in the performance of each of the three roles. Working memory capacity was more highly correlated with role performance and GPA was more highly correlated with team performance. Although both cognitive ability measures were significantly correlated with performance on the task, a different pattern of correlations was obtained in each experiment.
The Effects of Leadership Style and Workload on Team Alarm Reaction Performance and Team Satisfaction
Authors: Fallon Corey K. , Bliss James P.
Published: January 2012

Previous research has indicated that flight crew communication problems cause the majority of human errors in aircraft cockpits. Such problems may further degrade reaction decisions to unreliable alarm signals. In this research we examine how leadership style and workload affect collective reactions to unreliable alarms. Seventeen psychology student dyads from Old Dominion University were randomly assigned to act as pilots or copilots while performing complex psychomotor and alarm response tasks. Dyad leaders (pilots) were assigned to exhibit autocratic or participative leadership behaviors. Dyads reacted to ten alarms in each condition and were randomly assigned to a low or high psychomotor task workload group. Results indicated that dyads in the low workload group reacted to alarms significantly faster than dyads in the high workload group. Also, copilots indicated higher leadership satisfaction in the participative style. These findings suggest that alarm designers consider workload when implementing alarm systems, and that pilots should be trained to exhibit participative leadership qualities.
The Effects of Age on Gait Parameters during Adjustment
Authors: Spaulding Jeremy M. , Lockhart Thurman E.
Published: January 2012

Further understanding causes and characteristics of slip and fall accidents may aid in prevention of severe injuries and fatalities that result from these accidents. Moreover, understanding mechanisms associated with gait adjustment across a known slippery surface may help in proactively avoiding slips and falls. This study involved examination gait parameter characteristics of the lower extremities during different walking conditions.

This study consisted of exposing 14 younger and 14 older participants to controlled slippery conditions safely, while studying normal and adjusted gait characteristics (friction requirement, heel contact velocity, and step length). First, a baseline measure was done to study normal gait prior to any exposure to slipping. A second measure was done following a slip from a contaminated floor surface, but before the initiation of a second slip. The results indicate that there are significant gait parameter differences between younger and older individuals. Findings suggest that older individuals require an additional step to properly adjust gait for a contaminated walking surface.
Gender Differences in Exposure to Physical Risk Factors during Standardized Computer Tasks
Authors: Won Erik , Johnson Pete , Punnett Laura , Becker Theodore , Dennerlein Jack
Published: January 2012

The aim of this study was to determine whether there were differences in exposure to physical risk factors between genders in a series of standardized laboratory-based tasks on computer workstations adjusted to wubject anthropometry. METHODS: Thirty computer users (15 men and 15 women) completed five different tasks. Surface electromyography measured muscular activity in the shoulders (anterior deltoid, medial deltoid, and trapezius) and wrists (extensor carpi radialis, extensor carpi ulnaris, flexor carpi radialis, and flexor carpi ulnaris). Electrogoniometers and electromagnetic sensors measured posture of the wrists and shoulders, respectively. A force-sensing platform placed under the keyboard measured typing force. Whole body and upper extremity anthropometric measurements were recorded manually. RESULTS: Normalized muscle activity (EMG), the forces applied to the keyboard relative to the maximum force of the fingertip (%MVC), and range of motion were consistently higher for women. Shoulder posture was less neutral for women. Pearson correlations revealed strong associations between anthropometric variables (height, shoulder width, and arm length) and physical risk factors (EMG, range of motion, force) that are different between genders. CONCLUSIONS: Women have greater exposure to physical risk factors during identical tasks on a computer workstation. Exposure to these risk factors was strongly correlated to anthropometric differences between genders. This demonstrates how biomechanics plays a role and may contribute to the higher prevalence of upper extremity musculoskeletal disorders found in females.
Recovery and Repeatability of EMG Measures during Low-Intensity, Intermittent Isometric-Isotonic Shoulder Efforts
Authors: Iridiastadi Hardianto , Nussbaum Maury A.
Published: January 2012

A study was conducted to determine the adequacy of several recovery periods following a series of intermittent tasks, and to evaluate repeatability of changes in muscle fatigue measures during such efforts. Seven college-age students participated in this study that involved light intermittent abductions of the arm, performed in a supine posture. The exercise was maintained either until exhaustion or up to one hour, with contraction levels set at 20% of muscle strength. The same exercise was performed on five different days (Day 1, 2, 6, 8, and 11). Data collected included strength, perceived muscle discomfort, and amplitude and median power frequency of the myoelectrical signals obtained from the middle-deltoid muscle. Despite non-significant day effects, trends indicated that a minimum of two-day recovery period between sessions is needed. Additionally, poor intra-class correlations were found for changes in electromyography-based measures, indicating that care is needed when interpreting myoelectrical data as an indicator of fatigue during this type of exercise.
Recurrent Hand/Wrist Problems and Organisation of Work Involving Keyboard Use, Physical Strain and Work-Related Mental Job Stress
Authors: Devereux Jason
Published: January 2012

Job design issues have been implicated in the development of work-related neck and upper limb musculoskeletal disorders. This paper describes the results from about 2000 computer users involved in a base-line of a prospective study in the UK. The data support the ecological model of musculoskeletal disorders proposed in 1996 by Steve Sauter and Naomi Swanson. A sense of physical strain from performing 4+ hours of keyboard work per day and perceiving the job to be mentally stressful mediates the exposure-effect relationship between keyboard work and recurrent hand/wrist problems. This study has implications for job design. It supports the recommendations that jobs involving computer work should limit typing to less than 4 hours a day and organisational factors should be addressed to avoid mental stress. In addition, feedback regarding the physical aspects of the job design (organisation of work and physical workstation layout) may further reduce risks.
Trackball Modification Based on Ergonomic Evaluation
Authors: Morag Ido , Shinar David , Saat Keren , Osbar Anna
Published: January 2012

A workstation ergonomic study was conducted in Intel's manufacturing plant in Qiryat-Gat, Israel in response to an increasing trend of technicians' complaints regarding wrist discomfort and pain. The study was performed with a sample of 62 technicians, and a comparison was made of the use of the trackball at its current position of 15° (control group) vs. an improved position of 24° (test group). The hypothesis was that the trackball at its current position creates a physical load on the upper part of the body that may lead to wrist discomfort or pain. The study, which took place in a manufacturing area (clean room in the semi-conductor industry) characterized by heavy use of the upper body, showed that the average level of discomfort, as reported by the technicians, was lower in the test group than in the control group. Videotape analysis showed that minor wrist extension was also found in the test group. At the workstations with the improved trackball angle (24°) there was a dramatic decrease in the practice of technicians leaning against the workstation as a supporting device. These results led to an implementation of the new trackball angle in all 900 workstations on the plant-manufacturing floor and became part of the base line for future designs of all Intel's manufacturing plants worldwide.
Kinematic Evaluation of Pulling Carry-on Luggage
Authors: Jung Myung-Chul , Haight Joel M. , Freivalds Andris
Published: January 2012

From a kinematic standpoint, the objective of this study was to investigate forward pulling tasks that were rare in ergonomic studies, so handling carry-on luggage was determined as an application. Single-pole and traditional double-pole luggage was selected for the comparison under different conditions of load weights and walking speeds. Single-pole luggage had one curved and longer pole in the handle whereas double-pole luggage had two poles that were straight and aligned in parallel. Five male students participated in the study. Subjects walked on the specially fabricated doublewide treadmill at either self-chosen normal speeds or 20% faster than normal speeds with luggage of 15 or 23 kg load weights. During one stride, the peak angles, peak velocities and peak accelerations often segments including luggage were obtained from three-dimensional planes as kinematic parameters. The result showed that all three independent variables of luggage types, walking speeds, and load weights affected the motions of most segments. Due to a curved and longer pole in the handle, single-pole luggage was tilted more forward and gave more clearance between luggage and the body. This allowed the right leg to move more freely. The load weight of 23 kg carried with luggage caused the trunk to be slightly more flexed than 15 kg and the walking speeds typically affected the motions of the upper and lower extremities. The handle of luggage could be a potential design factor to be considered by luggage designers and other ergonomic evaluation approaches may be necessary for better understanding of pulling carry-on luggage.
The Effects of Body Awareness, Movement Direction, Visual Condition, and Movement Speed on Trunk Proprioception
Authors: Kelaher Dan , Glasscock Naomi , Mirka Gary
Published: January 2012

Research on the proprioceptive mechanisms of the trunk typically involves trunk repositioning tasks. However, this body of research involves numerous differences in the test methods, results, and interpretations. This research tested the effects of two of the methodological differences, the visual condition and the speed of movement, along with the plane of motion, on the accuracy and precision of trunk repositioning ability in the three primary planes of trunk motion. The results showed significant main effects of plane of motion and visual condition on both repositioning accuracy and precision. Significant interactions between speed and plane of motion and between the visual condition and plane of motion were found for trunk repositioning accuracy. Finally, there was a strong correlation between the overall repositioning precision and the combined score of the Kinesthetic and Proprioceptive Assessment Questionnaire and the Body Awareness Questionnaire.
Compression and Shear Loads on Lumbar Spine Motion Segments in Neutral and Flexed Postures
Authors: Gallagher Sean , Marras William S.
Published: January 2012

An analysis was performed to estimate compression and shear loads on three motion segments of the lumbosacral spine in neutral and flexed torso postures. 87 lifting tasks were evaluated using a biodynamic lifting model for lifts starting at 0, 22.5 and 45 degrees torso flexion. Results indicated that the compressive loading on the L5-S1 disk in the 22.5 and 45 degree torso flexion conditions were approximately double and triple those observed in the 0 degree condition. Shear reaction forces acted anteriorly in neutral and moderate flexion, but acted posteriorly in full flexion. Load rates were also dramatically affected by posture, with the load rate in the fully flexed posture being seven times greater than in the neutral posture. Analysis of the upper lumbar levels (L1–L2 and L3–L4) suggested significant shear forces; however, shear forces at L5-S1 remained moderate in all conditions. Results of this analysis will be used in a study examining the fatigue failure of lumbar motion segments when subjected to loads experienced at different angles of torso flexion.
Multitasking and Interruptions during Mobile Web Tasks
Authors: Nagata Stacey F.
Published: January 2012

Common traits of mobile computing are time critical tasks and interruptions that require multitasking. Essential for success of a mobile web task is quick and accurate performance. To facilitate performance in response to interruptions, an understanding of factors that influence multitasking during mobile computing is required. This study examines the effect of anticipation and origin (i.e. instant messaging, or phone and intercom) of an interruption on user web performance on a mobile device (iPAQ h3800 pocket PC) or desktop computer. Results show that instant messages can significantly disrupt web task performance time, contrary to popular belief that phones are more disruptive. Anticipated interruptions produce better web task performance particularly on a mobile platform. As expected, web tasks take 1.5 times longer to complete during interruptions on an iPAQ compared to a desktop.
On Trust in the Internet: Belief Cues from Domain Suffixes and Seals of Approval
Authors: Evil Atticus Y. , Shaver Eric F. , Wogalter Michael S.
Published: January 2012

Beliefs about the validity and reliability of Internet web-site information is important to both the user and to the success of a site. The present study examined aspects of reported trust of the Internet. A total of 247 participants (171 undergraduate students & 76 non-students) were asked a series of questions. In general, participants reported trusting only 55% of the information they found on the Internet. Students and non-students differed in their trust of .gov and .edu domain suffixes as well as several seals of approval (e.g., Verisign, Trust-e). In addition, the ratings of several fictitious seals were judged as trustworthy at levels as high or higher than actual seals. Participants who use the Internet for more hours per week showed significantly more trust for some domain suffixes and seals of approval than those who use the Internet for fewer hours. A similar pattern was seen for both students and non-students. Implications for erroneous beliefs and use of information on the Internet are discussed.
Symposium Overview: Validation Engineering Approaches for Reducing Medical Errors
Authors: Horst Richard L. , Krueger Gerald P.
Published: January 2012

Validation engineering (VE) is a structured, systematic approach to risk reduction and user hazard mitigation. This series of presentations will espouse the use of a VE framework in considering the ergonomics of medical systems. The first presentation will set the stage by arguing that medical errors should be viewed from a context-of-care perspective, in order to shift the focus from assigning blame to identifying and correcting the precipitating causes of adverse events. VE provides a means of being proactive in this regard, thereby avoiding the conditions that can lead to medical errors. The second presentation will describe the VE framework from a theoretical perspective, mapping out the typical VE lifecycle as a series of feedback and feed forward loops that ensure the systematic assessment of needs, the translation of needs to requirements, the derivation of quantifiable engineering specifications, the accurate translation of specifications to implementation, and then to deployment of the medical product or process. The third presentation will discuss issues that arise in applying this VE approach to ergonomic problems in the design of medical systems. We will emphasize the importance of observation-based measurement in dealing with VE processes and will show examples of metrics, methods, and software tools that can be used to manage a VE implementation.
Development and Evaluation of Just-in-Time Training to Provide Cardio-Pulmonary Resusciation
Authors: Drews Frank , Agutter James , Syroid Noah , Snell Dan , Balikrishnan Santosh , Lingutla Srinath , Westenskow Dwayne , Strayer David
Published: January 2012

More than 350,000 people die annually of cardiac arrest. In response to this epidemic, automated defibrillators are advocated, but they do not provide important respiratory support. However, adding respiratory support makes the system more complex and difficult to use. To solve this problem we developed a graphical computer based “just-in-time” training that instructs a responder to follow a standard treatment protocol. We simulated a medical emergency in a patient simulator and asked novice volunteers to care for the patient. When using a paper-based version of the treatment protocol (based on a NASA protocol), subjects took significant longer to remove an obstruction from the airway and stabilize the injured person than when using an animated graphic treatment protocol. These findings validate the potential of graphically based just-in-time training to instruct novices in tasks they have not performed before.
Methodological Considerations in a Human Factors Assessment of a Teledermatology System
Authors: Nichols Timothy A. , Stronge Aideen J. , Rogers Wendy A. , Fisk Arthur D. , Rasche Jeanette D. , Sessions G. Rufus
Published: January 2012

The U.S. military has initiated several telemedicine programs ranging from teledermatology to telemental health. Several advantages of telemedicine programs have been documented including increased patient satisfaction and decreased healthcare costs. However, not all telemedicine programs in the military have been successful (i.e., widely used). This analysis used multiple methods to identify the human factors issues involved in using a teledermatology system. The methods included task analyses, decision-action diagrams, and a questionnaire distributed to subject matter experts (SMEs). In a progressive fashion, each method contributed to development of the next method. Task analyses guided the development of decision-action diagrams. Decision-action diagrams identified critical human factors issues within the system and led to the development of questionnaire items specifically targeting those areas (e.g., workload, errors). The results from this assessment demonstrate how multiple methods can be used to analyze a system, identify human factors issues, and suggest interventions.
Building the Executive Dashboard
Authors: Resnick Marc L.
Published: January 2012

Executive dashboards are systems that provide business intelligence to company executives and managers by presenting data from a wide variety of sources in ways that support effective monitoring and decision making. They are linked to a company's data warehouses or other sources of data from operations, finance, marketing, and other domains and thus must provide visualizations that allow users to comprehend what can be an enormous quantity of data. In order to do so, the designer must consider many of the formats that have been identified in human factors practice to support various kinds of data and tasks. Many executive dashboards include capabilities to aggregate data from multiple sources, drill down to examine specific data, analyze historical or conceptual trends, and other functionality. These added capabilities add a significant amount of complexity to the design that must be addressed carefully. Users are often experts in their domains (ie. marketing) but not necessarily proficient with information technology or data analysis. The design must satisfy the needs of the users while providing a simple and context-dependent interface in order to be effective. This paper describes many of the human factors issues involved in creating executive dashboard systems and suggests some areas for future research.
The Train-Project: Effects of Organizational Factors, Automatic Train Control, Work Hours and Environment: Suggestions for Safety Enhancing Measures
Authors: Kecklund Lena , Olsson Eva , Jansson Anders , Kecklund Göran , Ingre Michael
Published: January 2012

The purpose of the TRAIN project was to describe and analyse the train drivers information environment, working hours, work situation and work environment and their effect on drivers' behaviour and the train driver system safety as well as to propose safety enhancing measures. The results indicate several problems of significance to the train driver system safety, which have been grouped into three main areas; organizational support functions, information environment including cognitive ergonomics and ATC and also working hours, work situation and work environment.