bluuebunny/crossref_metadata_2025 huggingface dataset:
Theoretical Concepts for Work Domain Analysis, the First Phase of Cognitive Work Analysis
Authors: Naikar Neelam
Published: January 2012

Cognitive work analysis (CWA) is gaining recognition as a promising approach for the analysis, design, and evaluation of complex, sociotechnical systems. However, the successful and widespread application of work domain analysis (WDA), the first phase of CWA, is limited by the lack of a coherent theoretical approach. This paper addresses a number of theoretical issues relating to WDA, including differences in the approaches of Rasmussen, Pejtersen & Goodstein (1994) and Vicente (1999), and it illustrates these theoretical issues with a work domain of a home — a 'system' that will be highly familiar to everyone. This research will help to: make WDA more accessible to researchers and practitioners who were not involved in the development of WDA or who cannot be apprenticed to experts in WDA; reduce the amount of time and effort it takes to perform WDA even for experts in the area; and facilitate the application of WDA to large-scale, industry projects.
Cognitive Model of Team Collaboration: Macro-Cognitive Focus
Authors: Warner Norman , Letsky Michael , Cowen Michael
Published: January 2012

The purpose of this paper is to describe a cognitive model of team collaboration emphasizing the human decision-making processes used during team collaboration. The descriptive model includes the domain characteristics, collaboration stages, meta- and macro cognitive processes and the mechanisms for achieving the stages and cognitive processes. Two experiments were designed to provide empirical data on the validity of the collaboration stages and cognitive processes of the model. Both face-to-face and asynchronous, distributed teams demonstrated behavior that supports the existence of the collaboration stages along with seven cognitive processes.
Conveying Work-Centered Design Specifications to the Software Designer: A Retrospective Case Analysis
Authors: Eggleston Robert G , Roth Emilie , Whitaker Randall , Scott Ron
Published: January 2012

It has been noted that there is a gap between the analysis and products produced by cognitive engineers (CEs) and what is needed by software engineers who must implement CE-based requirements in the final product medium. In this paper, we report on a retrospective analysis of intermediate design artifacts that were produced from a CE and work-centered design perspective during the course of developing a successful work-centered support system software application. The analysis involved an examination of design analysis and synthesis artifacts produced by the development team that were made available to the software engineers. It concentrated on how work-centered information and requirements were conveyed and made useful to the software engineering staff. Based on this analysis, we suggest that a work-centered specification package needs to contain at least three classes of information: (1) work-centered descriptions of the work context, work activity, and support requirements, (2) principles and guidance specifying “work centeredness” and (3) detailed specifications of the aiding solution with links back to the support requirements.
Melioration Despite More Information: The Role of Feedback Frequency in Stable Suboptimal Performance
Authors: Neth Hansjörg , Sims Chris R. , Gray Wayne D.
Published: January 2012

Situations that present individuals with a conflict between local and global gains often result in a behavioral pattern known as melioration —– a preference for immediate rewards over higher long-term gains. Using a variant of a paradigm by Tunney & Shanks (2002), we explored the potential role of feedback as a means to reduce this bias. We hypothesized that frequent and informative feedback about optimal performance might be the key to enable people to overcome the documented tendency to meliorate when choices are rewarded probabilistically. Much to our surprise, this intuition turned out to be mistaken. Instead of maximizing, 19 out of 22 participants demonstrated a clear bias towards melioration, regardless of feedback condition. From a human factors perspective, our results suggest that even frequent normative feedback may be insufficient to overcome inefficient choice allocation. We discuss implications for the theoretical notion of rationality and provide suggestions for future research that might promote melioration as an explanatory mechanism in applied contexts.
A Cognitive Engineering Approach for Facilitating Analysis of Human-Computer Interaction in Complex Work Domains
Authors: Xu Wei
Published: January 2012

This paper demonstrates that work domain analysis (WDA), a cognitive engineering approach based on Rasmussen's abstraction hierarchy (AH) framework, is a valuable and alternate analytic tool for analyzing human-computer interaction (HCI) in complex work domains through a case study. In the case study, we use WDA to examine automation awareness, an HCI issue in automated flight decks. The case study shows that WDA provides an effective approach to systematically assess collected human factors data in order to identify the gaps in satisfying the work requirements across interrelated factors. It helps assess the adequacy of domain information provided to workers via training in order to build a fairly accurate and effective mental model, adequacy of domain information presented to workers at the interface, and the adequacy of operation procedures designed for workers to copy with unfamiliar situations. Finally, WDA also helps generate needs for enhancements of existing systems from a work domain perspective.
Defining the Challenges Operators Face when Controlling Multiple Unmanned Vehicles
Authors: Squire Peter N. , Parasuraman Raja
Published: January 2012

To achieve effective human-robot interaction (HRI) it is important to determine what types of supervisory control interfaces lead to optimal human-robot teaming. Research in HRI has demonstrated that operators controlling fewer robots against opponents of equal strength face greater challenges when control is restricted to only automation. Using human-in-the-loop evaluations of delegation-type interfaces, the present study examined the challenges and outcomes of a single operator supervising (1) more or less robots than a simulated adversary, with either a (2) flexible or restricted control interface. Testing was conducted with 12 paid participants using the RoboFlag simulation environment. Results from this experiment support past findings of execution timing deficiencies related to automation brittleness, and present new findings that indicate that successful teaming between a single human operator and a robotic team is affected by the number of robots and the type of interface.
Overcoming the Keyhole in Human-Robot Coordination: Simulation and Evaluation
Authors: Voshell Martin , Woods David D. , Phillips Flip
Published: January 2012

When environment access is mediated through robotic sensors, field experience and naturalistic studies show robot handlers have difficulties comprehending remote environments - they experience what domain practitioners often call a 'soda straw'. This illustrates the keyhole effect in Human Robot Interaction, a CSE phenomena studied in the context of large virtual data space interfaces and the current research seeks to reduce this effect. A simulation for human-robot coordinated search and rescue was created based on WTC response experiences. Pilot studies showed traditional performance measures to be inadequate in analyzing control and exploration tasks therefore a novel analysis approach based on fractal path tortuosity was developed. New interface concepts for helping remote observers perceive environmental affordances were then tested using the simulation environment and evaluation measures. These studies look to concepts based on Gibsonian principles to reduce keyhole effects in control interfaces to enhance remote functional presence in Human-Robot Coordination.
Effects of Attribute and Goal Framing on Automation Reliance and Compliance
Authors: Lacson Frank C. , Wiegmann Douglas A. , Madhavan Poornima
Published: January 2012

Presentation of an aid's reliability may have mixed results on utilization due to differences in the way the reliability is framed, as well as its effects on reliance versus compliance. Using an aided signal detection task, the current study compared effects of attribute framing (80% correct versus 20% incorrect) and goal framing (focusing on hits and correct rejections versus misses and false alarms) on sensitivity, response bias, compliance, and reliance. Sensitivity and response bias results indicated few differences between aided groups. Information framing did lead to differences in compliance, but not reliance compared to an unframed group. However, reliance differences occurred when comparing positive and negative framing group. These results indicate that the manner in which information about the reliability of a diagnostic aid is presented can have significant, albeit subtle, effects on automation utilization.
Validation of a Two Factor Structure for System Trust
Authors: Safar Jennifer A. , Turner Carl W.
Published: January 2012

Customers assess a company's ability to meet their needs based upon service interactions with that company. The growth of the Internet as an information transfer medium has dramatically increased reliance on communication between a human and a computer during service interactions. Although trust is known to be an integral part of customer experience during human-to-human interactions, it has been suggested that even when service is provided by an inanimate entity, trust remains a relevant factor. This study evaluated a tool purporting to measure system trust during automated service interactions. Participants completed an auto rate quote via one of two insurers' websites. A two-factor structure was uncovered. The scale exhibited strong internal consistency, sensitivity to objective task success, and was significantly related to several other customer experience measures. The results provide convergent evidence that the scale is a valid and reliable tool for describing customers' experiences during automated interactions.
Large Scale Coordination: The Study of Groups at Work
Authors: Nemeth Christopher P.
Published: January 2012

Naturalistic decision making (NDM) methods have previously been applied to understand individual and group cognition. The systemic aspects of work that are unavailable through the study of individuals or a single group can be revealed by cognitive research at large scale, among and across groups. The papers in this symposium explore the use of NDM methods including cognitive systems engineering to reveal how groups of operators have developed ways to perform inter-group work in real world settings. Insights from such studies inform the development of system-level products, including safety countermeasures and information and communication technology (ITC) that is intended to support this work.
Challenges to Remote Emergency Decision-Making for Disasters or Homeland Security
Authors: Mackenzie Colin , Hu Peter Fu-Ming , Fausboll Carsten , Nerlich Michael , Benner Thomas , Gagliano David , Whitlock Warren , Lam David , Xiao Yan
Published: January 2012

New technology allows information gathering and collaboration across information networks that would be of benefit to emergency response. In a Homeland Security Exercise we compared the utility of fixed and mobile video and high quality still images on remote expert decision making. Sixteen experts situated in 3 countries viewed and evaluated events of the exercise assisted by audio commentary of local knowledge experts. They evaluated the usefulness of black and white (B/W) compared to color images, fixed fast video versus slow video and still images. Technical difficulties interrupted image transmission to one remote site for half the Exercise. However, the images were found useful, color more than B/W, mobile more than fixed. The combination of still images and video was best. Playback of recorded images was especially useful for remote evaluation and decision making. Improved reliability for these imaging technologies could improve shared awareness and remote distributed team collaboration for Homeland Security events
Take the Advice of a Decision Aid: I'D Rather be Wrong !
Authors: Beck Hall P. , Dzindolet Mary T. , Pierce Linda G.
Published: January 2012

It has been proposed that operators sometimes refuse to follow the guidance of a decision aid that they know is offering correct or useful advice (intent errors). To test this premise, some participants received a “recommendation” from a computerized decision aid before each of 100 target detection trials. These operators were told that the aid always offered correct advice. A control group performed the same task without the decision aid. Most of the aided participants (82%) made one or more errors because they were unwilling to follow the aid's recommendations. Furthermore, the number of errors made by the experimental and control groups was not statistically different. Extrapolation of the results suggests that efforts to reduce automation disuse should include training designed to mitigate intent as well as appraisal errors.
Searching for Cues: An Analysis on Factors Effecting the Decision Making Process of Regional Airline Pilots
Authors: Khoo Yee-Len , Mosier Kathleen
Published: January 2012

Research on aviation accidents and incidents has indicated humans are potentially the “weak link” in the chain of accident causation. The problem faced by researchers here is there is often no clear standard of determining what decision is “correct” or “incorrect“. In addition, the loose coupling of an event outcome and the decision process makes it hard researchers to use accident reports as a reliable indicator of the quality of the decision. The goal of this research is to explore cognitive processes of pilots when dealing with the types of decisions required under time pressure and with conflicting information and how pilots use information as they are performing diagnostic and decision-making tasks in the automated cockpit. Differences were found between pilots with more experience in automated aircrafts however predicted automation bias effects were non-apparent.
Predicting Group Decision-Making with a Computerized Text Analysis Tool
Authors: Dzindolet Mary T. , Stover Arleta , Pierce Linda G.
Published: January 2012

Decision-making tasks are often performed in groups because it is believed that a discussion of the topic from varying individual perspectives will lead to a better decision. However, researchers find group members often spend the majority of their discussion time focused on information members have in common rather than on unique pieces of information each group member holds (Stasser & Titus, 2003). Determining which groups are most likely to fall into this trap would benefit team leaders. A computerized text program, the Linguistic Inquiry Word Count (LIWC), offers one technological tool to meet this need. Significant correlations between LIWC word categories and time groups spent discussing common information, discussing unique information, and making the decision were found among 104 students who assessed candidates for student government president in face-to-face groups of two or four. The linguistic profile of groups following this unproductive pattern is identified and suggestions for further research are discussed.
Comparing Computer Input Devices Using Kinematic Variables
Authors: Slocum Jeremy , Chaparro Alex , McConnell Daniel , Bohan Michael
Published: January 2012

Throughput (TP) is a global measure of input device efficiency but provides little information about user's movement behavior when interacting with a device. Psychomotor models of movement provide a framework from which to develop new “during” movement variables that can be used to explain why efficiency differences occur. Data from a previous study examining the usability of a mouse, trackball and RollerMouse™ was re-examined using TP and the kinematic variables peak velocity of the primary movement (PV) and proportion of total distance traveled in primary phase (%PMD). Partial correlation analysis found %PMD and PV to be significantly related to TP and negatively related with each other, suggesting a “speed/accuracy” tradeoff. Further analysis confirmed the variables were useful in discriminating between devices and found that the most efficient device was less constrained by the “speed/accuracy” tradeoff. It was concluded that kinematic variables offer a useful way of understanding efficiency differences between devices.
Incremental Transfer and Cost Effectiveness of Groundbased Flight Trainers in University Aviation Programs
Authors: Rantanen Esa M. , Talleur Donald A.
Published: January 2012

Use of ground-based flight training devices in flight training is attractive for several reasons. In addition to undeniable safety aspects and immunity to weather, ground trainers also offer benefits in terms of training effectiveness, typically measured by the time or number of trials saved over training exclusively in an airplane. A review of 19 studies from the past 56 years that have investigated transfer of training effectiveness from ground trainers to airplane revealed, however, that unambiguous conclusions about the best use of these devices are difficult to discern. The reason for the lack of valid data and widely varied results are the large number of intervening variables present in flight training as well as the difficulty of conducting sound research on this topic.
Thermal Effects on Office Productivity
Authors: Hedge Alan , Sakr Wafa , Agarwal Anshu
Published: January 2012

A field study was conducted to investigate the associations between indoor thermal conditions and productivity for computer workers in an insurance company. Thermal environment conditions and productivity were logged every 15 minutes for 9 women workers for 16 consecutive work days. Results showed an association between thermal conditions and productivity, which was highest when conditions fell in a thermal comfort zone and lowest when conditions fell below this zone. The findings have important implications for the design and management of workplaces.
Levels of Automation in the Brave New World: Adaptive Autonomy, Virtual Presence and Swarms-Oh My!
Authors: Miller Christopher A.
Published: January 2012

The concept of Levels of Automation (LOAs) as a categorization of distinct combinations of human-automation relationships arrayed along, usually, a spectrum of possibilities has a long and fruitful tradition in Human Factors. Nevertheless, if a proliferation of novel LOA schemes and uses is any evidence, there is some reason to perceive unrest and dissatisfaction with comparatively simple LOA schemes that have been proposed in the past. This panel will review concepts and uses of Levels of Automation schemas and discuss their relative strengths and weaknesses. A central theme will be whether novel automation capabilities (and, therefore, novel human-machine interaction opportunities) demand revisions to LOA concepts or whether we can (or have) defined a scheme that defines the full space of possible interaction types.
Identifying Performance Obstacles among Intensive Care Nurses
Authors: Gurses Ayse P. , Carayon Pascale
Published: January 2012

In this paper, we compare findings of two studies aimed at identifying performance obstacles among intensive care nurses. The first study is a qualitative study where data was collected from 15 intensive care nurses using individual, semi-structured interviews. The second study is a cross-sectional study conducted among 298 nurses from 17 intensive care units (ICUs) of seven hospitals using a questionnaire survey. Based on the results of these two studies, the most commonly experienced performance obstacles among ICU nurses include inadequate help from others, tools and equipment, ineffective inter-provider communication, materials and supplies, poor physical work environment, and family issues. The results of these two studies have implications regarding efforts aimed at redesigning ICU work organization in order to reduce nursing workload and improve quality of working life and quality and safety of care.
Handoffs During Nursing Shift Changes in Acute Care
Authors: Patterson Emily S. , Roth Emilie M. , Render Marta L.
Published: January 2012

Handoffs during the nursing shift change were directly observed on two acute care wards each of a private and public hospital, for a total of 236 patient updates by 49 nurses during 14 shift changes. Data from the three wards which conducted audio-taped updates were transcribed. The transcriptions and field notes were analyzed for the existence and frequency of 21 strategies used in high reliability organizations. In addition, we iteratively categorized the interruptions, questions, and statements made during the updates. Finally, we iteratively categorized stances towards decisions communicated during the updates. Implications of the findings are discussed.
Robotic Surgery and the Operating Room Team
Authors: Lai Fuji , Entin Eileen
Published: January 2012

Robotic surgery has the potential to revolutionize the field of surgery and improve patient safety. However, despite the advantages robotic surgery can offer, there are multiple human factors-related issues that may prevent these systems from realizing their full benefit. This study identified some of the salient human factors issues and considerations that need to be addressed for integration of new technologies such as robotic systems into the Operating Room of the future. We conducted in-depth interviews with operating team members and other stakeholders who have experience with robotic surgery to identify workflow, teamwork, training, and other clinical acceptance issues. Addressing these and other human factors issues will help the integration of surgical robotic systems into use for the ultimate goal of improving patient safety and healthcare quality.
Cognitive Human Performance Modeling by Demonstration
Authors: John Bonnie E.
Published: January 2012

Cognitive human performance models have enjoyed a rich history in human-computer interaction but have yet to make a widespread impact in system design, possibly because they are difficult to construct. We employed user-centered design techniques to develop a new tool that is easier to use than previous methods or tools. CogTool combines a familiar method of prototyping, modeling by demonstration, and the ACT-R cognitive architecture to enable user interface designers to make valid human performance models with little effort.
Non-Intrusive Measurement of Workload in Real-Time
Authors: Guhe Markus , Gray Wayne D. , Schoelles Michael J. , Liao Wenhui , Zhu Zhiwei , Ji Qiang
Published: January 2012

We present a new method to measure workload that offers several advantages. First, it uses non-intrusive means: cameras and a mouse. Second, the workload is measured in real-time. Third, the setup is comparably cheap: the cameras and sensors are off-the-shelf components. Fourth, we go beyond measuring performance and demonstrate that just using such measures does not suffice to measure workload. Fifth, by using a Bayesian Network to assess the workload from the various manifesting measures the model adapts itself to the individual user as well as to a particular task. Sixth, we use a cognitive computational model to explain the cognitive mechanisms that cause the differences in workload and performance.
Human Performance Modeling for Operational Command, Control and Communication
Authors: Hansberger Jeffrey T. , Barnette Diane
Published: January 2012

The challenges facing the military due to adversaries, new battlegrounds, and everchanging technology requires innovative, fast, and efficient means to conduct and support research. The Army Research Laboratory has developed a modeling environment, C3TRACE (Command, Control, and Communication — Techniques for Reliable Assessment of Concept Execution), that aids in the evaluation of different personnel architectures and information technology on system and human performance. This modeling environment, which was originally designed to address tactical command issues, has been applied to a higher level organizational command and control environment within the Joint Forces Command. Specifically, it was applied to an urban operations exercise to evaluate the effect of various personnel structures and communication means on awareness, flow of information, and decision-making.
Human Performance Modeling in the Army: A Long and Winding Road
Authors: Allender Laurel , Kelley Troy , Lockett John , Archer Sue
Published: January 2012

The history of human performance modeling (HPM) in the U.S. Army is described, the early influences and technological events that made it possible. Highlights of significant milestones are presented, including HPM efforts that were influential in influencing the U.S. Army's modeling practices and in changing system design. The latest challenges in cognitive modeling, advanced decision making, stressors, and the particular challenges of distributed and linked simulations are discussed as well as the prospect of using methods from neuroscience for validation of cognitive models.
Time-Based Modeling of Human Performance
Authors: Rantanen Esa M. , Levinthal Brian R.
Published: January 2012

This paper presents a probabilistic approach to modeling human performance. Instead of focusing on mean performance, the effects of taskload on the distributions of performance variables are examined. From such data, probabilities of given levels of performance can be derived and methods of measurement that expand the analyses beyond those of the mean developed. Results from two experiments, one abstract, the other realistic, are presented in terms of timely performance on required tasks. As taskload increased, the participants were less likely to act on the experimental tasks at an earliest opportunity than under low taskload, resulting in increase of “too late” errors. Measurement of taskload and performance in temporal terms also allowed for bracketing and making inferences about mental workload, which is not directly measurable.
Being Optimismtic may Not Always be Advantageous: The Relationship Between Dispositional Optimism, Coping, and Performance
Authors: Helton William S. , Matthews Gerald , Warm Joel S. , Dember William N.
Published: January 2012

The effects of dispositional optimism on performance and self-reports of coping strategy were examined in a low and a high signal salience vigilance task performed in quiet or during exposure to jet-aircraft engine noise. The results of this study partially support Scheier and Carverâ€™s (1985; 1987) habitual coping styles theory, in which people varying in optimism differ in their general coping strategies. Optimism in most cases correlated positively with task-focused coping and negatively with off-task approaches. When the task setting elicited a coping style contrary to dispositional preference, however, performance was actually impaired. In the low-salience, quiet condition of this experiment optimism correlated negatively with performance; this condition also elicited elevated levels of maladaptive, off-task coping. Being highly optimistic may not always be an advantage in performance settings
Comparison of Biomechanical and Anatomical Effects Following Eccentric and Concentric Exertions
Authors: Chourasia Amrish O. , Sesto Mary E. , Jung Youngkyoo , Howery Robert S. , Radwin Robert G.
Published: January 2012

Work place exertions may include muscle shortening (concentric) or muscle lengthening (eccentric) contractions. This study investigates the upper limb mechanical properties and magnetic resonance images (MRI) of the involved muscles following submaximal eccentric and concentric exertions. Twelve participants were randomly assigned to perform at 30° per second eccentric or concentric forearm supination exertions at 50% isometric maximum voluntary contraction (MVC) for 30 minutes. Measurement of mechanical stiffness, isometric MVC, localized discomfort and MRI supinator: extensor signal intensity ratio was done before, immediately after, 1 hour after and 24 hours after the bout of exercise. A 53% average decrease in mechanical stiffness after 1 hour was observed for the eccentric group (p< 0.05) compared to a 1% average decrease for the concentric group (p> 0.05). Edema, indicative of swelling, was observed 24 hrs after exercise, with an average increase in the MRI supinator: extensor signal intensity ratio of 36% for the eccentric group and less than 10% for the concentric group (p<0.05).
Experience on an Elevated Inclined Surface and Postural Control
Authors: Wade Chip , Davis Jerry
Published: January 2012

Historically, roofing work has been ranked among the highest of all industries with incidents of fatal and non-fatal falls. The purpose of this study was to investigate the exposure to an elevated inclined surface on postural stability. Twenty males, 10 experienced roofers, and 10 inexperienced college students participated in this study, which consisted of a preliminary balance test, followed by exposure to an elevated inclined surface for ten-minutes of exposure. While subjects walked, a motion analysis system recorded their position on the elevated roofing surface to determine the amount of time a subject spent in each of two areas, central or peripheral. Results suggest that both experienced and inexperienced individuals demonstrated decreased postural stability following exposure to the elevated inclined surface, with experienced individuals demonstrating a lesser decrement. Furthermore, experienced individuals spent a significantly greater portion of time in the peripheral area (extremities of the elevated roofing surface) surface compared to inexperienced individuals. These findings suggest that there is a significant decrement in postural stability due to exposure to an elevated inclined support surface.
Lifting Performed on Laterally Slanted Ground Surfaces
Authors: Jiang Zongliang , Shin Gwanseob , Freeman Jacklyn , Reid Stephanie , Mirka Gary A.
Published: January 2012

Many outdoor work environments (e.g. agriculture and construction) require manual material handling activities on variable grade ground surfaces. Quantifying biomechanical responses for lifting under these conditions may provide insight into the etiology of lifting-related injuries. The aim of the current study was to quantify the effect of laterally slanted ground surfaces on biomechanical responses. Ten subjects performed lifting exertions (using a 40% of max load) while standing on a platform that was laterally tilted at 0, 10, 20 and 30 degrees from horizontal. During the lifting tasks the whole body kinematics were collected, which were later used in a dynamic biomechanical model to calculate the time-dependent moment about L5/S1 and the time-dependent lateral forces acting on the body segments. The results showed a consistent reduction in the peak dynamic L5/S1 moment (decreased by 9%) and an increase in the lateral forces (increased by 111%) with increasing slant angle.
Neuromuscular Control and Active Trunk Stiffness during Isometric Flexion and Extension
Authors: Granata Kevin , Lee Patrick
Published: January 2012

Pushing and pulling tasks account for 20% of low-back injury claims. Torso flexion necessary for pushing exertions requires different muscle recruitment than for extension exertions typical of lifting tasks. These differences in recruitment and control may influence spinal stability and associated risk of injury. Active muscle stiffness is considered the primary stabilizing mechanism for spinal stability. Therefore, active trunk stiffness was recorded while subjects generated upright isometric trunk flexion and extension exertions against an isotonic preload. Small pseudo-random force disturbances were superimposed on the preloads causing small amplitude trunk movements. Trunk stiffness was computed from systems identification of the measured force and trunk motion data. Results demonstrated significantly greater stiffness during flexion exertions as compared to extension exertions. EMG data suggest this difference was due to increased co-contraction during the flexion exertions. These behaviours were attributed to the need to augment neuromuscular control of spinal stability during pushing tasks. Keywords: Spine; Co-contraction; Push; Manual Materials Handling; Biomechanics
The Role of Ergonomics in Reducing Low Back Pain and Disability in the Workplace
Authors: Snook Stover H.
Published: January 2012

Low back pain is a common problem, an expensive problem, and a recurring problem. In this paper, the problem is defined, the available evidence is reviewed, and three types of interventions are discussed. The interventions are job design, changing personal behavior and beliefs, and secondary intervention to reduce the disability. Ergonomics plays an important role in each of the interventions. Although low back pain cannot be completely prevented, the evidence indicates that it can be reduced and managed with considerable success.
Ergonomic Field Assessment of Bucking Bars during Riveting Tasks
Authors: Jorgensen Michael J. , Viswanathan Muthukurappan
Published: January 2012

Riveting tasks in aircraft manufacturing results in exposure to vibration from both rivet guns and bucking bars. Long term exposure to vibration has been associated with symptoms of vibration white finger and musculoskeletal disorders. Four different bucking bars of the same shape but different material and mass characteristics (90% tungsten, >90% tungsten, cold rolled and stainless steel) were investigated for vibration and grip muscle activity during a riveting task. The >90% and 90% tungsten bars (3.4 m/s2 and 3.6 m/s2, respectively) resulted in significantly less mean resultant weighted acceleration when compared to the cold rolled and stainless steel (5.3 m/s2 and 5.6 m/s2, respectively), whereas there was no difference in mean hand grip flexor or extensor muscle activity. These results suggest that for bucking tasks that allow access for the bucking bar size investigated, use of heavier but same sized tungsten bucking bars can reduce vibration transmission to the hand.
Repeatability of an Exposure Assessment Method for Job Rotation
Authors: Kotowski Susan , Davis Kermit , Jorgensen Michael
Published: January 2012

As job rotation has become a widely used intervention strategy for the prevention of a wide variety of musculoskeletal disorders, there is a need for the development of assessment techniques that take into account the complexities of multiple body region stressors. The current study investigates the repeatability of a video-based analysis method that combines the exposure measure of four body regions: neck, shoulder, low back, and hand/wrist. Twelve analysts completed the assessment twice for 15 different job rotation schemes. The repeatability was found to be strong (ICC > 0.53) in many of the body regions when individual jobs were evaluated with minimal decrease in repeatability when the entire rotation scheme was considered. Overall, the video-based method provides a potential quick and easy method that will allow for the versatile evaluation needed for practitioners when quantifying exposure for job rotation schemes.
Prediction of 2-D Lift Motions Using Artificial Neural Networks: An Evolutionary Approach
Authors: Perez Miguel A. , Nussbaum Maury A.
Published: January 2012

Movement prediction is an important aspect of human simulation, where more efficient and accurate models are needed. Artificial neural networks could potentially serve as a modeling option in this realm. This investigation evaluates the performance of a particular artificial neural network structure in modeling sagittally symmetric two-dimensional lifting and lowering movements. Model performance was evaluated using three training datasets, each consisting of distinct representation levels of the overall dataset. Results are discussed in terms of their practical meaning, and suggestions for future improvements in the modeling scheme are provided. Overall, artificial neural networks show promise as a modeling paradigm for the prediction of human movement.
An Empirical Study of Paid Listings in Product Search and Purchase
Authors: Resnick Marc L. , Jansen Bernard J.
Published: January 2012

Pay-for-placement search has been described contradictorily as either the future business model of information retrieval on the Internet or as a deceptive nuisance for unsuspecting Web surfers. This study investigated user interaction with paid search listings during a set of naturalistic product search and purchase tasks. The study compared objective measures of how often these listings are used and subjective user opinions both during and after the task. Participants were more likely to view and select organic listings than paid listings. They also rated the organic results as more relevant for the shopping tasks and expressed suspicion of the paid listings. However, some users did use the paid listings and when the content was relevant there was no difference in the relevance ratings of the content pages themselves. A lack of neutral ratings for paid listings suggests that users will respond either negatively or positively to the paid listings, creating a difficult decision for online retailers and product search companies when considering whether to support paid search listings.
Ranking versus Categorization: The Effects of Sorting the Results for Web Search Engine Multiterm Queries
Authors: Aurelio David N. , Mourant Ronald R.
Published: January 2012

Many Web search engine users have difficulty writing search queries and finding a useful query result. One element of ineffective Web searches is that many search engine queries are ambiguous or their results do not include the desired information in their first page. The objective of this research was to investigate the effects of sorting the results of multiterm queries. The sorting methods included Categorizing and Ranking. The dependent variables consisted of user performance and preference measures. Statistical analyses revealed that when the correct result was found on page 1 of the results, the Ranking sorting method was associated with faster trial times, fewer false alarms, higher trial ratings, and the preferred sorting method. However, when the correct result was found on subsequent pages, the Category sorting method was associated with better performance and increased preference.
A Comparison of Subject-Based Classification Strategies for Enhanced Usability
Authors: Ahlstrom Vicki
Published: January 2012

Collections of documents, such as technical notes, are often classified on websites using a set of keywords that describe general subject areas. These keywords are used as a set of links to help the user navigate to the information he or she is seeking. This subject-based classification is intended to help users find information. A poorly designed subject-based index can make it difficult or impossible for users to find the information they need, however, creating an effective subject-based index is not easy. There are many different classification strategies that can be used. Each of these strategies can result in a different set of key words/key phrases. Some of these strategies may result in an index that is more usable than others. This paper addresses the problem of how to create a subject index that facilitates usability. Several strategies are compared against user search data. The five strategies resulted in differences in search success rate and efficiency.
The Design and Presentation Order of Web Page Buttons
Authors: Bangor Aaron W. , Miller James T.
Published: January 2012

As part of a guidelines standardization effort, a company wanted to know what customers think a “good” button looks like for web sites. A study was conducted with 63 participants that had them rank-order four existing button designs and then asked follow-up questions about their preference for several button characteristics. Results show that participants preferred bold text for labels, dark characters on a lighter background, rounded corners, and the button and page background colors to be different. One of the four designs was preferred over the other three, even though it embodied only three of the four preferred characteristics. The horizontal ordering of button pairs was also investigated. Participants preferred Save to the left of Cancel and Next to the right of Back, but did not indicate a preference for Continue with respect to Cancel. Possible reasons for these findings and future research topics are discussed.
An Investigation of the Potential to Influence Braking Behaviour Through Manipulation of Optical Looming Cues in a Simulated Driving Task
Authors: Li Zhonghai , Milgram Paul
Published: January 2012

This paper reports on an investigation of how manipulation of optical looming cues can influence braking behaviour, for automobile driving in a low-fidelity simulator. Twenty participants were instructed to follow a leading vehicle (LV) and appropriately respond to braking events of the LV, which occurred randomly and at different deceleration rates. During some braking events, the size of the LV was manipulated in different ways, without subjects being aware, in a manner concordant with the optical expansion that would have been observed during braking if the LV had been displaced to be closer or further away. Results showed that subjects braked sooner when confronting an expanding LV and later for a contracting LV, relative to a constant-size LV, to an extent corresponding to the magnitude of the manipulation. The experiment supports the theory that drivers use TTC information derived from optic looming to control braking.
Task and Effector Constraints on the Kinematics of Pointing Movements
Authors: Bohan Michael , McConnell Daniel , Thompson Shelby , Chaparro Alex
Published: January 2012

Recent work has emphasized the distinction between task and effector constraints underlying performance in Fitts' type discrete pointing tasks. We explored the relative contributions of these constraints in a cursor-pointing task by manipulating the control-display scale, thereby dissociating movement scale at the level of the hand from movement scale at the level of the cursor. Using linear regressions to predict movement time, we found that effector constraints best predict the primary transport phase of the movement, bringing the hand near the target. Visual task constraints underlie the secondary target acquisition phase of the movement. We present a reformulation of Fitts' (1954) index of difficulty, capturing the relative contributions of effector and visual task constraints.
Naïve Realism: Limits of Realism as a Display Principle
Authors: Smallman Harvey S. , John Mark
Published: January 2012

Display designers are often called upon to create visualizations of complex geo-spatial environments for users engaged in tasks such as civil emergency, air traffic, or military operations. What visualization principles exist to guide them? One principle is to strive towards realism, on the belief that realistic depictions result in near effortless comprehension. We think this faith in realism is misplaced and term this misplaced faith Naïve Realism. Naïve Realism appears to stem from the folk belief that scene perception is simple, accurate, and rich, when, in fact, perception is remarkably complex, error-prone, and sparse. It results in the development of realistic displays that give users flawed, imprecise representations. Therefore, Naïve Realism offers a new account of why users sometimes prefer displays that subsequently under-perform. We review the evidence for Naïve Realism, its origins, why it persists, and conclude with a discussion of how good design can counteract it
Displaying Depth in Computer Systems: Lessons from Two-Dimensional Works of Art
Authors: Pazuchanics Skye Lee , Gillan Douglas J.
Published: January 2012

Virtual depth displays depend on static, monocular cues. Models of integrating monocular cues may be continuous (additive) or discontinuous. Previous research using simple displays and a small number of cues supported continuous cue integration. The present research is designed to expand the understanding of how the visual system integrates information from multiple pictorial cues by investigating combinations of one to ten pictorial cues in visually-rich, two-dimensional displays (paintings and photographs). Participants estimated depth in target paintings and photographs relative to a standard two dimensional display. Certain results suggest that the visual system integrates cues in a largely additive way, but after a number of cues are present there may be an additional boost in perceived depth resulting in a best-fittingdiscontinuous model of cue combination. However, this discontinuous effect may be due to designdecisions made by the painters rather than exclusively to the perceptual processes of the viewers. Analyses of these design decisions provide lessons for the design of two-dimensional displays.
Spatial Audio as a Navigation Aid and Attitude Indicator
Authors: Simpson Brian D. , Brungart Douglas S. , Dallman Ronald C. , Joffrion Jacque , Presnar Michael D. , Gilkey Robert H.
Published: January 2012

Most current display systems in general aviation (GA) environments employ, at best, relatively simple audio displays that do not fully exploit a pilot's auditory processing capabilities. Spatial audio displays, however, take advantage of the spatial processing capabilities of the auditory system and have the ability to provide, in an intuitive manner, comprehensive information about the status of an aircraft to the pilot. This paper describes a study conducted in order to assess the utility of spatial audio as (1) a navigation aid, and (2) an attitude indicator in an actual flight environment. Performance was measured in tasks requiring pilots to fly in the direction of a spatial audio “navigation beacon” and use an auditory artificial horizon display to detect changes in attitude and maintain straight and level flight when no visual cues were available. The results indicate that spatial audio displays can effectively be used by pilots for both navigation and attitude monitoring, and thus may be a valuable tool in supporting pilot situation awareness and improving overall safety in GA environments.
Compressed File Length Predicts Search Time and Errors on Visual Displays
Authors: Donderi D. C. , McFadden Sharon
Published: January 2012

Search times and errors were recorded for targets (a triangle or trapezoid) in marine radar, chart, and radar-chart overlay bitmap computer displays. Lossless JPEG and ZIP compressed file lengths were obtained for each display. The two types of file length were correlated and they predicted both the maximum time to search each display and the number of errors made per search. Compressed file length is analogous to algorithmic complexity, a theoretical measure of bit string complexity. It predicts both subjective complexity judgments (previous research) and search performance (this study) for a set of static marine electronic displays. The data suggest that compressed file length will predict minimum anticipated performance in a range of applied visual search tasks