bluuebunny/crossref_metadata_2025 huggingface dataset:
What we do with Human Factors Data and Theory: A Flight Deck Design Philosophy for the High Speed Civil Transport Aircraft
Authors: Dresel K. Michael , Pepitone David D. T.
Published: January 2012

This paper reports on the results and lessons learned from constructing a design philosophy for a new aircraft. The High Speed Civil Transport aircraft is the next-generation supersonic transport, planned for initial operating capability in 2005. Current objectives for the aircraft include cruise speeds of Mach 2.4, ability to take off and land in low visibility, and restricted forward vision. These objectives necessitate consideration of major changes in some of the functions currently allocated to the human flight crew. An explicit design philosophy was defined as the first step in ensuring that system development proceeded with clear emphasis on supporting the human operators in accomplishing the goals of transporting their passengers and cargo safely, comfortably, efficiently and on schedule. This paper discusses the development and details of the integrated flight deck design philosophy that will be used to guide the development of a High Speed Civil Transport flight deck. The paper describes

• the goals, scope and benefits of the flight deck design philosophy;

• the effect on the current system development process;

• the method used to produce the design philosophy;

• examples of the philosophy and guideline statements, with rationale;

• and finally, suggestions for improving the transfer of basic and applied research into the system design process.
Automated Data Analysis
Authors: Connelly Edward M.
Published: January 2012

Automated Data Analysis (ADA) is a powerful, flexible analysis tool for systematically building performance determinants. ADA is designed to assist analysts in assessing the linkage from system processes to outcomes. It allows for or accounts for the varying conditions during performances and permits formation of complex analyses which extract relevant information from multiple variables while ignoring irrelevant data from the data base. In particular, ADA permits:

1. Focus on selected portions of the performance space, 2. Characterization of the system processes and examination of the relationship between system processes and outcomes, 3. Building analysis variables which can be made simple or as complex as necessary as knowledge of the importance of system processes to outcomes is obtained, and 4. Use of powerful prestructured analysis tools.
Signal Word and Color Specifications for Product Warnings: An Isoperformance Application
Authors: Braun Curt C. , Sansing Lori , Kennedy Robert S. , Silver N. Clayton
Published: January 2012

Recent work in the area of color and warnings has indicated that the level of hazard communicated by signal words varies as a function of the color in which they are printed. These findings suggest that signal word and color combinations create a continuum of perceived hazard. Although individual experiments advance the understanding of how color affects the perception of product hazard, explicit data do not always provide label designers and product manufacturers with the tools necessary to successfully apply them. To explore how color and signal words can be jointly used, the present effort applied the isoperformance technique to the problem of specifying signal word and color combinations. This technique identifies combinations of variables that produce equal (iso) levels of warning (performance). Using perceived hazard data from 30 participants, signal words and colors were systematically grouped into categories that conveyed equal levels of hazard. How the isoperformance technique might serve as a tool for label designers is described.
Software Usability Testing: Do User Self-Consciousness and the Laboratory Environment Make any Difference?
Authors: Barker Richard T. , Biers David W.
Published: January 2012

The purpose of the study was to evaluate the effect of laboratory environment, user self-consciousness, and user experience on the user's subjective evaluation of software usability. The study employed a 2 × 2 × 2 factorial between-subjects design with 2 levels of Laboratory Environment (Cameras and Mirror vs. No Cameras and Mirrors), 2 levels of User Self-Consciousness (Low vs. High), and 2 levels of User Experience (Novice, Experienced). The users were asked to learn, then use, and finally subjectively evaluate a restricted subset of common word processing features over three hours of participation. Day 1 was a training day and Day 2 was a test day. Results indicated that high self-conscious and novice users make more word processing errors. However, they were no more likely to make those errors in the presence of cameras and a mirror. More importantly, the evidence for any effect of the independent variables on subjective evaluation was sparse–limited to the interaction of self-consciousness and laboratory environment on just three of twelve factors. Moreover, the pattern of these interactions indicated that self-consciousness and the laboratory environment did not influence subjective evaluation in any predictable manner. Despite some methodological shortcomings, the conclusion was drawn that these variables do not have a major impact on subjective evaluation of software usability.
Improved Training Methods: Research to Applications
Authors: Moses Franklin L.
Published: January 2012

How to train people to make good decisions, solve problems, and so on depends, as does all training, on some form of practice and feedback. The question for behavioral research often is how to improve on these basic requirements. Six panelists describe and discuss their research and experience with the relationship among training and factors such as group dynamics, stress, mental models, and naturalistic requirements. This session includes interaction among the panel and the audience.
Training with Images: Real and Representational
Authors: Bailey Sandra S.
Published: January 2012

A total of 60 subjects (24 males and 36 females) participated in a study to determine if a caricature's accentuation of critical cues results in improved recognition of handshapes used in the American Sign Language manual alphabet. Each subject was randomly assigned to one of two training groups. One group trained with photographs of the handshapes and the other group used caricatures. Once mastery of the alphabet was demonstrated, their ability to recognize the handshapes shown in four different modes (positive and negative photographs, and positive and negative caricatures) was tested. In the unrestricted condition, the duration of exposure was not artificially constrained. In the restricted testing condition, the handshapes were displayed at 320 msec, 500msec and 700 msec. Both speed and accuracy were equally emphasized in the training and in the testing. The findings did not support the superfidelity hypothesis of caricatures. In the unrestricted condition, those trained with photographs responded significantly faster, regardless of mode, than those trained with caricatures. As predicted in the most restrictive display time (320msec), mean response time was significantly faster with caricatures. This study has direct implications regarding the media used to train American Sign Language. The findings support the use of photographs to depict and to train novices in the ASL handshapes. Further research is needed to determine if these findings hold true as the complexity of the handshape increases.
Massed versus Distributed Practice in Complex Skill Acquisition
Authors: Shebilske Wayne L. , Corrington Kip , Jordan Jeffrey A.
Published: January 2012

A training sequence on a complex video research task was distributed over 10 days or massed within two days. Measures of fatigue and confidence were taken. A final test battery given 1 week after acquisition consisted of retention tests, a test of resistance to interference, and a test of transfer. Trainees in the Distributed condition performed better throughout. Massed and Distributed trainees showed moderate levels of fatigue and did not differ from each other. Differences in confidence could not account for the results. Theories based on massing simple task acquisition within an hour are discussed as a framework for understanding and reducing suppression caused by massing complex tasks within days.
Using the Backward Transfer Paradigm to Validate the AH-64 Simulator Training Research Advanced Testbed for Aviation
Authors: Stewart John E.
Published: January 2012

The Simulator Training Research Advanced Testbed for Aviation (STRATA) is a modular research simulator which in its current configuration represents the AH-64 helicopter. The backward transfer of training paradigm was employed to determine if AH-64 piloting skills transfer to STRATA. Ten AH-64 pilots participated in the experiment. They performed a mission scenario consisting of 13 Aircrew Training Manual (ATM) tasks. No orientation or practice was allowed. Most participants rated STRATA as highly similar to the AH-64 in handling. Real-time performance ratings indicated that of 130 task events, 88.5% were performed to ATM standards. After the experiment, four independent judges rank-ordered performance on the hover task using output from STRATA'S performance measurement system. Rankings showed high concordance and a high correlation with real-time ratings.
Evaluating a Maintenance Crew Resource Management Training Program; Effects on Attitudes, Behaviors, and Performance
Authors: Robertson Michelle M. , Taylor James C. , Stelly John W. , Wagner Robert
Published: January 2012

A Crew Resource Management program for maintenance personnel has been developed by an airline company which involves several team related concepts. Technical operations managers' pre and post-training attitudes and their follow-up attitudes (2, 6 and 12 months afterwards) concerning a variety of management and organizational factors were compared with one another as well as with maintenance performance measures. Comparisons of participants' attitudes before and after their training showed a significant improvement in attitudes indicators and these attitudes remained stable overtime. Positive trends for two of the maintenance performance indicators are demonstrated in comparing pre and post training performance measures. Increased safety and improved on-time performance was found related to improved attitudes about participation and assertive communication. Open ended responses as well as anecdotal evidence confirms the positive changes in attitudes and behaviors.
The Influence of Stimulus Dimensions and Training on Visual Search Performance
Authors: Czerwinski Mary P. , Feldman Evan M. , Cutrell Edward
Published: January 2012

Traditional studies of attention, training and visual search have focused on the use of separable dimensions (usually alphanumeric stimuli), and equating the number of items in consistent versus varied mapping training paradigms. However, the design of visual displays requires a heavy reliance upon configural and integral dimensions (stimuli that group). This set of studies examines the effects of configural dimensions (also using alphanumeric stimuli), as well as equating the number of training trials on specific targets between consistent versus varied mapping conditions. Predictions from extant theories of attention and visual search will be discussed where relevant. Results show that both factors have a large influence on the effects of training in visual search tasks. The influence of these variables needs to be incorporated into current theories of attention and visual search, especially as they are applied to the design of graphical user interfaces and visual displays.
Relevant Cues for the Visual Perception of Depth: Is Where You See it Where it is?
Authors: Surdick R. Troy , Davis Elizabeth T. , King Robert A. , Corso Gregory M. , Shapiro Alexander , Hodges Larry , Elliot Kelly
Published: January 2012

We tested seven visual depth cues (relative brightness, relative size, relative height, linear perspective, foreshortening, texture gradient, and stereopsis) at viewing distances of one and two meters to answer two questions. First, which cues provide effective depth information (i.e., only a small change in the depth cue results in a noticeable change in perceived depth). Second, how does the effectiveness of these depth cues change as a function of the viewing distance? Six college-aged subjects were tested with each depth cue at both viewing distances. They were tested using a method of constant stimuli procedure and a modified Wheatstone stereoscopic display. Accuracies for perceptual match settings for all cues were very high (mean constant errors were near zero), and no cues were significantly more or less accurate than any others. Effectiveness of the perspective cues (linear perspective, foreshortening, and texture gradient) was superior to that of other depth cues, while effectiveness of relative brightness was vastly inferior. Moreover, stereopsis, among the more effective cues at one meter, was significantly less so at two meters. These results have theoretical implications for models of human spatial perception and practical implications for the design and development of 3D virtual environments.
Vigilance: How to Do it and Who Should Do it
Authors: Sawin David A. , Scerbo Mark W.
Published: January 2012

The present laboratory study examined variables that are believed to impact vigilance in operational settings. First, instructions given to subjects were manipulated in order to impact their feelings of “command pressure” (Mackie, Wylie, & Smith, 1985). It was expected that instructions emphasizing detection efficiency would lead to increased subjective workload. Further, it was expected that decreasing instructional demands by emphasizing relaxing qualities of the task would not impact performance, though lower workload ratings were expected. In addition, response bias was manipulated by telling subjects to adopt either a conservative or a liberal criterion. Secondly, subjects' boredom proneness (BP) was measured to test the predictive validity of this measure in vigilance. All subjects monitored a VDT of uniform color for 30 min. They were asked to respond to 110 ms “long flickers” embedded in a matrix of 50 ms “short flickers” occurring at a rate of 15 per min. As expected, detection-emphasis subjects reported significantly higher workload. Overall performance regarding proportion of hits and A' was not impacted significantly by command emphasis, though an Emphasis x Bias interaction revealed that relaxation-liberal subjects performed more poorly than subjects in the remaining conditions. Finally, BP scores significantly predicted overall hits and A'. Results indicate that (1) much of what individuals find unpleasant about vigilance may lie with the demands implied by the initial instructions and (2) valid personality predictors of vigilance performance exist.
A Comparison of Sequential and Spatial Displays in a Complex Monitoring Task
Authors: Konrad Christopher M. , Kramer Arthur F. , Watson Stephen E.
Published: January 2012

A sequential or RAP COM display was compared to a more conventional spatial display as subjects monitored dynamically changing sets of numbers and responded to occasional target stimuli. In an effort to equate the stimulus-response compatibility of the two displays subjects responded to the targets with a chord keyboard. We examined the influence of display duration on the performance with the RAP COM and spatial formats by presenting the stimuli at three different durations, 400, 800 and 1200 msec. The influence of practice on performance with the RAP COM and spatial displays was also investigated. Targets were responded to more quickly in the RAP COM than in the spatial displays at each of the three presentation durations and across over 2000 trials of practice. Accuracy was influenced by the display presentation duration. Accuracy was higher for the RAP COM than the spatial display at the 800 msec stimulus presentation duration. Accuracy was statistically equivalent for the RAP COM and spatial displays at the 400 and 1200 msec display durations, although there was a trend for lower accuracy for the RAP COM display at the faster presentation duration. Interestingly, the lower accuracy for the RAP COM display format at the 400 msec presentation duration appears to be due to illusory conjunctions. Our results will be discussed in terms of the utility of sequential or RAP COM displays in complex, real-world settings.
Animated Mimic Displays
Authors: Bennett Kevin B.
Published: January 2012

Animated mimic displays represent the physical structure of a system, including: 1) the important components, systems, or subsystems, 2) the physical/causal connections between components, and 3) the flow of information or resources through these connections. This type of display has the potential to improve both the effectiveness of real-time performance and the efficiency of training. A research program has been initiated to determine critical factors in the design of animated mimic displays. The initial display designs were based on examples of animated mimic displays found in the literature. Four sets of psychophysical experiments investigated 1) chromatic/luminance contrast, 2) spatial/temporal frequency, 3) contours/borders, and 4) stairstep/sinusoidal waveforms. The first two sets of experiments revealed that existing designs were not effective. A theoretical explanation was developed and is discussed briefly. The second two sets of experiments investigated alternative display designs based, in part, upon these theoretical insights. The results indicate that the alternative designs will improve the effectiveness of animated mimic displays. A set of design guidelines are provided.
Three-Dimensional Displays for Terrain and Weather Awareness in the National Airspace System
Authors: Boyer Bradley , Campbell Margaret , May Patricia , Merwin David , Wickens Christopher D.
Published: January 2012

Three experiments are reported in which participants (air traffic controllers, Experiments 1 and 2; pilots, Experiment 3) were required to guide an aircraft around the hazards of terrain (Experiment 1) and weather (Experiments 2 and 3), using either 2D (planar) or 3D (perspective) displays. In Experiment 2, air traffic controllers, but not pilots, were less accurate in projecting tracks around terrain with the 3D display than with the 2D display. In Experiment 2, there was little difference between display formats in their ability to support safe vectoring around weather. In Experiment 3, pilots took slightly longer to plan a route around weather with the 3D display, and did so with equivalent accuracy to the 2D display. In all three experiments, the 3D display supported creation of paths that were slightly longer, and skirted the hazard by a wider margin than did the 2D display.
A Ten-Year Overview of USAF F-16 Mishap Attributes from 1980–89
Authors: Holland Dwight A. , Freeman James E.
Published: January 2012

The F-16 Falcon jet fighter is a marvel of engineering. Having been in operational United States Air Force service since approximately 1980, this fly-by-wire aircraft can climb vertically, sustain a 9-G turn without the loss of airspeed, and fly greater than the speed of sound. With such capabilities, this aircraft was originally designed and conceived of as a daylight air-to-air “dog-fighting” pilot's dream. As time has passed, the F-16 aircraft has been tasked with carrying out much more diverse missions than only day air-to-air combat. The aircraft and highly-trained pilots that fly it now accomplish additional missions such as day and night ground attack. An examination of ten years of USAF Safety Center accident data revealed that the F-16 aircraft had 59 Class A operational mishaps during this period. This was the highest number for any single-seat fighter-attack aircraft, and second only to the Aggressor's “Red Flag” F-5 per 100,000 hours of flight time (Class A Accident Rates: F-16 2.86 v. F-5 4.76). Incidentally, about 73% of the Royal Netherlands Air Force pilots reported that they were more susceptible to spatial disorientation and loss of situation awareness in the F-16 compared to other fighter aircraft that they had flown. After 11 years of operational experience, 21 of 210 of the Netherlands' F-16 aircraft were destroyed. A detailed examination of the USAF database revealed that a host of human factors issues are pertinent to the F-16 such as the loss of situation awareness, spatial disorientation, G-induced loss of consciousness, etc.; all of which contributed heavily to the accident rates cited for this aircraft. Additionally, cockpit design issues relatable to man-machine interfacing present human factors challenges to the pilot as well depending upon the mission scenario. The majority (53%) of F-16 accidents occurred during low-level or maneuvering flight. About 20% of the F-16 mishaps happened during the takeoff or landing phase of operations. Over 60% of the accidents were deemed by investigating officers to have “channelized attention” as a definite contributor to the mishap rate. Other human factors issues such as task oversaturation, distraction, and a variety of spatial disorientation problems contributed to many of the accidents also. Cockpit improvements, research, better training/awareness programs and Ground Collision Avoidance Devices (GCAS/PARS) are all suggested as methods to reduce future F-16 Falcon accident rates.
Dual Task Assessment of Age Differences in Mental Workload with Implications for Driving
Authors: Baldwin Carryl L. , Schieber Frank
Published: January 2012

Older drivers constitute the fastest growing segment of the driving population, in terms of both number of drivers and number of miles driven. Accident analyses reveal that older drivers are not able to fully compensate for emerging reductions in perceptual/cognitive capacity. Establishment of a method of assessing older drivers with perceptual/cognitive impairments which place them at risk of accidents is imperative. In this investigation, a subsidiary task of mental arithmetic was demonstrated to be sensitive to age differences in relative mental workload resulting from increased steering task complexity in a simulated driving task. As steering task difficulty increased, verbal response latency to concurrent mental arithmetic problems increased for older, but not younger, participants. Steering error remained stable across single and dual task conditions indicating that the secondary mental arithmetic task did not interfere with steering (primary task) performance. These results provide preliminary support for the use of this assessment technique outside of the laboratory in actual driving situations.
Graphic Data Model Perception
Authors: Crosby M. E. , Nordbotten J. C.
Published: January 2012

This paper describes an experiment in reading graphic data models which differ in graphic style. Computer science students participated in an experiment to determine if graphic style influences data model comprehension. Models with embedded graphic symbols, graphically separated symbols, or list structures were used. Protocol data, which consisted of verbal reports and eye-movements, was collected. Detailed analysis of this data provided insight into how students viewed the four types of data models. Results from this study suggest that the graphic style of the model effects the ease with which they are read and understood.
Factors Affecting Remote Positioning Performance
Authors: Hsu Shang H. , Huang Chien C.
Published: January 2012

The purpose of this study was to investigate the effects of target width, movement direction, movement amplitude, and remote distance on remote positioning performance. Movement time and movement distance ratio were taken as measures of remote positioning performance. It was found that the effects of target width, movement amplitude, and movement direction on the two measures were significant. The effect of remote distance was significant only for movement distance ratio. The magnitude of the effect of target width on movement time was larger than that of movement amplitude; a modification of Fitts' Law was thus proposed. Moreover, there was an interactive effect between target width and movement direction- i.e., movement direction had an effect only when the target width was small. Among the eight movement directions, upward vertical movement was the best for remote positioning. The results shed some light onto the design of remote control user interface.
Colortool: An Information Tool for Cross Cultural Design
Authors: Vanka Surya , Klein David
Published: January 2012

Color meanings vary dramatically across cultures. Sometimes globally marketed products fail, either commercially or in use, because designers were unaware of culture specific meanings associated with the colors they selected. Designers generally tend to base color decisions on aesthetic reasons, and on anecdotal knowledge of cultures. This is primarily because of the lack of truly useful information tools that can assist them in making informed cross cultural color choices. ColorTool is a computer based tool that designers can use to learn about culture-specific color dialects, to search for colors associated with specified meanings, or to check the cultural appropriateness of aesthetic color choices. This paper describes the development, use, and evaluation of ColorTool. Further, it discusses the potential for network tools that could involve cultural experts and even users in the color selection process.
User Preferences between Keyboards while Performing “Real” Work: A Comparison of “Alternative” and Standard Keyboards
Authors: Morelli Donald L. , Johnson Peter W. , Reddell Cheryl R. , Lau Patricia
Published: January 2012

The proliferation of varying computer keyboard designs may pose problems to those who specify, purchase and ultimately use such devices. Are any of them “best” for my work? Will actual users derive any benefit from them? To assist in addressing such issues, we explored an approach to determining if any of three “alternative” keyboards provided a benefit to employees by increasing user comfort. A total of 34 employees participated in this study, each using an “alternative” keyboard for one week at a time while performing their actual work. After using each keyboard, including their standard “101” keyboard, subjects completed a questionnaire of seven psychophysical measures relating to the comfort and use of the keyboard. Questionnaire responses were tabulated and a Repeated Measures Analysis of variance conducted. Statistically significant differences were found among and between the four keyboards on four of the seven psychophysical measures. Overall results showed little differences in user assessments between three of the keyboards, with the fourth keyboard assessed less favorably when significant differences were found. The results suggest that user assessments can produce significant results between keyboards, and that no one “best” keyboard exists for any given set of tasks and group of users.
Using Simulations in Teaching Human Factors: Bridging the Gap between the Academic World and the World of Work
Authors: Moroney William F. , Cameron Joyce A.
Published: January 2012

The nature of the world of work in which human factors professionals practice requires both knowledge and skill. Students of human factors need educational experiences which demand more than the acquisition of information in order to be prepared for this world. To meet this need for a broader educational experience, we incorporated three simulations into the design of a graduate course in Human Factors in Systems Development.

The decision to use these three simulations required not only a restructuring of the course content, but also a reconsideration of instructional procedures. Fortunately, in the field of education there are “models of teaching” which can assist individuals who want to use simulations in teaching by providing guidance in shaping curriculum, in designing instructional materials, and in guiding instruction.

The purpose of this paper is fourfold: (1) to describe the curriculum and the simulations used, (2) to indicate the type of educational objectives associated with each simulation, (3) to share a model of teaching which is intended specifically for use in conjunction with the use of classroom simulations, and (4) to relate some ideas about other types of simulations that we have begun to incorporate into other courses.

It is our belief that the use of simulations can enhance the learning of both content and skills. More important, it can provide students with opportunities to experience the consequences of their individual and group efforts at problem-solving and decision making, and it can help bridge the gap between the academic experience and the world of work.
Analysis and Design Recommendations for Workstations: A Case Study in an Insurance Company
Authors: Cohen William J. , James Craig A. , Taveira Alvaro D. , Karsh Ben-Tzion , Scholz Julie , Smith Michael J.
Published: January 2012

A case study approach was used to determine the effects of task demands, customer needs, and organizational environment on the recommendations for ergonomic redesign in a large pension and insurance organization. The organization was planning a major renovation of workstations and requested assistance with design and implementation. Three job positions were studied using semi-structured interviews, job observations, and measurements of workstations and the office environment. It was found that most work surfaces and chairs were inadequate for VDT tasks, reception counters presented problems for both the employees and claimants, and the use of shared VDTs on a swivel base resulted in eyestrain and poor postures. In addition, there was inadequate storage space and poor housekeeping for all three jobs, as well as lighting and noise problems throughout the office environment. Recommendations were made for new workstations, with pilot testing to be conducted before full-scale implementation. Although existing workstations were inadequate, it was found that task demands were of greatest concern to the employees.
Effects of Office Layout and Sit-Stand Adjustable Furniture: A Field Study
Authors: Paul Rajendra D
Published: January 2012

In a controlled field study, twelve office employees with computer-intensive jobs were monitored during the redesign of their work environment. Before office redesign, they worked in closed offices with four walls and sitting height, non-adjustable workstations. Then they worked in more open offices with three walls and sit-stand adjustable VDT workstations. The effects of this office redesign were evaluated three months post-occupancy. During the three months, employees worked standing for two hours every day. The results suggest that change in the office layout, i.e. open versus closed, increased the interaction and communication between employees. However, it significantly decreased employees' perceived privacy, and increased the amount of visual and noise distractions. In the offices with sit-stand adjustable furniture, subjects felt more energetic and less tired by the end of the workday.
Mapping the Domain of Electronic Repair Shops: A Field Study in Fault Diagnosis
Authors: Reising Dal Vernon C. , Sanderson Penelope M.
Published: January 2012

Recent experimental research has indicated that different multiple faults impose differing levels of objective and subjective difficulty on human troubleshooters. Technological advances suggest that systems are becoming more complex and integrated, in which case multiple components will fail. Operators will have to be able to deal with these more complex failures. In this paper we report field work conducted in order to build and substantiate a model of the factors influencing fault diagnosis in the field. By conducting field observations and by constructing concept maps, we investigated how expert troubleshooters handle the difficulty associated with diagnosing multiple faults. The troubleshooters were expert electronic technicians in departmental repair shops on a large university campus. The end product of the research is a model of fault diagnosis that is grounded in field data. Our results suggest that diagnostic difficulty arises from several factors: (1) organizational structure, (2) technicians' strategies for fault diagnosis, and (3) equipment design. The field observations and concept maps indicate that technicians approach the diagnostic task with standard, ritualistic methods that they have developed over years of experience. They generally go through two phases of troubleshooting: (1) the problem definition phase and (2) what we call the At-the-Equipment-TroubleShooting (AETS) phase. Technicians also reason about multiple failures in series, considering one simple explanation at a time. Our principal conclusion is that in real-world settings the three previously mentioned factors have evolved to avoid situations in which technicians must engage in prolonged functional reasoning. These findings will be used (1) to develop further the model of fault diagnosis, and (2) to guide future experimental investigations studying the influences of fault diagnosis.
Cognitive Task Analysis Using Complementary Elicitation Methods
Authors: Gordon Sallie E.
Published: January 2012

Cognitive task analysis is accomplished using a wide variety of methodologies, and we have previously argued that different methods will tend to elicit qualitatively different types of knowledge and skills. Because of this, many practitioners use complementary methods for a given project. We have developed such a complementary package of knowledge elicitation techniques, along with a specific representational method, which together are termed conceptual graph analysis. Conceptual graph analysis is domain-independent and can be used to evaluate complex cognitive tasks or subtasks. It relies on the successive use of document analysis, interviews, task observation, and induction based on review of task performance. The information from these elicitation techniques is represented as a set of interrelated conceptual graphs, but can be represented in other formats also. There are several issues relevant to cognitive task analysis that are currently being faced, including when to perform this type of analysis, and what methods to use. One answer is to perform cognitive task analysis when the task has an inherently high degree of cognitive complexity.
The Value Added by Cognitive Task Analysis
Authors: Klein Gary
Published: January 2012

Cognitive Task Analysis (CTA) attempts to describe how people perform tasks: the cues and patterns they use, their inferences and strategies, mental models, and other related topics. It differs from behavioral task analyses that seek to enumerate the steps that must be followed without examining the expertise needed to perform critical steps. Therefore, CTA provides a more in-depth picture, which complements the broader and more comprehensive behavioral task analysis.

A CTA usually consists of five steps: Preparation, Knowledge Elicitation, Data Analysis, Knowledge Representation, and Application. The applications of CTA can take a number of forms, such as training, system design, personnel selection, and market research.
Task Analysis, Cognitive Task Analysis, Cognitive Work Analysis: What's the Difference?
Authors: Vicente Kim J.
Published: January 2012

The term cognitive task analysis (CTA) has been appearing in the human factors literature with increasing frequency. Others have used the term cognitive work analysis (CWA). Is there a difference? Do either of these methods differ from traditional task analysis (TA)? If so, what advantages can CTA/CWA provide human factors engineers? To address these issues, the history of work analysis methods and the evolution of work are reviewed. Work method analyses of the 19th century were suited to manual labor. As job demands progressed beyond the physical, traditional TA was introduced to provide a broader perspective. CTA has since been introduced to increase the emphasis on cognitive task demands. However, CTA, like TA, is incapable of dealing with unanticipated task demands. CWA has been introduced to deal with complex systems whose demands include unanticipated events. The initial evidence available indicates that CWA can be applied to industry-scale problems, leading to innovative designs.
A Mechanical Model of Hand Force in Power Hand Tool Operation
Authors: Radwin Robert G. , Oh Seoungyeon , Fronczak Frank J.
Published: January 2012

A three-dimensional static equilibrium mechanical model of power hand tool operation was developed and used for comparing hand force associated with use of nutrunners having similar operating parameters (i.e. torque and feed force) but different physical parameters (i.e. shape, size, and mass distribution). The model used a Cartesian coordinate system relative to the orientation of the handle grasped in the hand using a power grip. Several important relationships between tool parameters and required hand force were revealed. Resultant hand force associated with different torque and feed force requirements were compared between four pistol grip nutrunners, and between pistol grip and right angle tools used for the same operation. Accessory handles and counterbalancers are also included in the model. Further development and validation of this model will be useful to power hand tool designers and tool engineers.
Analysis of Hand Tool Grips
Authors: Yun Myung Hwan , Freivalds Andris
Published: January 2012

An efficient measurement and evaluation system for hand tool tasks can provide a practical solution to the problem of designing and evaluating manual tool tasks in the workplace. Such a prototype system, termed the data glove, was developed by overlaying twelve Force Sensitive Resistors on an posture-measuring glove (Cyberglove™, Virtual Technologies, 1992) with eighteen joint angle sensors. To validate the data glove, hand posture and grip force was measured on sixteen different cylindrical grip tasks for six subjects. A factor analysis of the grip force distributions on the hand indicated that three major areas of force concentration occurred: 1) an area of high force levels termed the ‘active’ area, 2) an area of intermediate force levels termed the ‘support’ area, and 3) an area of low force levels termed the ‘inactive’ area. The different grips were also classified and ranked for levels of radian/ulnar deviation torques and flexion/extension torques, and then combined with the force information to yield a pattern of grip degradation with increasing levels of grip stress. A validation experiment comparing the data glove force output with the muscle surface EMG measurement yielded a significant, high correlation between the two measures.
The Effect of a Commercially Available Support Belt on Torso Posture, Lift Strength, and Spinal Compression
Authors: Sherman Brian Randall , Woldstad Jeffrey C.
Published: January 2012

The purpose of this research was to measure changes in torso posture when a commercially available abdominal support belt was worn. In addition, this study investigated whether the belt affected static lift strength and predicted spinal compression of the L3/L4 intervertebral disc.

Eight males and eight females were asked to perform maximal static exertions on handles attached to a steel rig. Lifts were performed from symmetric and asymmetric positions at different heights while the support belt was worn and not worn.

It was found that static lift strength and torso posture, with the exception of axial twist, were not significantly affected by belt use. Axial twist for low asymmetric exertions was significantly larger when the belt was worn as compared to when the belt was not worn. Predicted spinal compression was significantly lower when the belt was worn (2738 N) as compared to the nonbelt conditions (3087 N).
Selective Activation of the External Obliques during Twisting
Authors: Kelaher Dan , Mirka Gary , Baker Ann , Harrison Angela , Davis Joe
Published: January 2012

This study investigated selective activation of different regions of the external obliques. Six subjects performed sub-maximal isometric axial twisting exertions (20%, 40%, 60% of MVC) while assuming six different postures defined by three levels of axial rotation (-20°, 0°, 20°) and two levels of sagittal flexion (0° and 20°). As the subjects performed these isometric exertions, the integrated EMG activity was sampled at five different locations on both the right and the left external oblique muscles. The results showed significant differences in the activation of different regions of each of the external obliques. The implications of selective activation of these muscles on spine biomechanics are discussed.
Wrist Posture during Computer Mouse Usage
Authors: Damann Elizabeth A. , Kroemer Karl H.E.
Published: January 2012

In this experiment, we investigated the effects that mouse pad surface height and wrist support had on wrist posture. In a pointing task, 16 subjects moved a mouse-controlled cursor clockwise or counterclockwise around three fixed targets, which varied by size and distance depending on task condition. Wrist extension, flexion, radial deviation, and ulnar deviation data were collected via a wrist monitor attached to the right hand and forearm.

The presence of a wrist support decreased wrist extension and radial deviation, and increased wrist flexion. Higher pad surface height resulted in increased flexion and ulnar deviation, and decreased extension and radial deviation. A comparison of the conditions which were at the same pad height, but differed due to the presence or absence of wrist support, revealed that wrist extension was reduced by the presence of a wrist support at all but the highest height.
Generation of Isocomfort Working Area Based on Psychophysical Evaluation
Authors: Jung Eui S. , Park Sungjoon , Han Sung H.
Published: January 2012

For efficient operations, vital hand controls must be easily controlled by the operator from his or her normal working position. The primary working area based on operator's working comfort was developed to serve as a design guideline to the workplace design or the control panel layout. Six males and four females participated in the experiment in which working comfort was measured for a lever control with respect to the frontal and sagittal distances from the body center and the slope of a work table. The response surface methodology using a central composite design was employed to develop a prediction model for perceived working comfort. The concept of the proposed working area is a significant extension to the conventional working area such as Farley's or Squires' curves. It is shown that the distance to a control instrument and the slope of a work table have a quadratic effect to working comfort. It is noticeable that comfortable working area also exists outside the conventional working area. The result of the response surface analysis also indicated that a little slope of about 15° for a work table improved working comfort.
Quantitative Measures in the Ergonomic Examination of the Trauma Resuscitation Units Anesthesia Workspace
Authors: Harper Ben D. , Mackenzie Colin F. , Norman Kent L.
Published: January 2012

This study examines the anesthesia care providers' workspace in the trauma resuscitation bay of the shock/trauma unit of a university hospital. Intubation, the placement of a tube into the trachea to facilitate ventilation, is performed in critical cases brought to the trauma resuscitation unit. This analysis focuses on the task of intubation and explores the utility of a measure of equipment location efficiency called Workspace Appropriateness.
Development of Experimental Protocol to Quantitativey Assess the Neuromuscular Control Capability of Low-Back Pain Patients
Authors: Kim Jung-Yong , Parnianpour Mohamad , Marras William S.
Published: January 2012

An experimental protocol was developed in this study in order to quantify the control capability of the trunk movement for LBP patients. Fitts' law (1954) was employed to measure the dynamic performance parameters such as flexion/extension velocity and acceleration with controlled ROM and the information processing capacity (bits/second) of the trunk. A series of statistical analyses were performed to reduce the length of protocol for clinical application; 11 indices of difficulty (ID= log2(2A/W), A: ROM, W: target tolerance) used by Kim et al. (1993, 1994) were shortened into 3 ID conditions. The accuracy of the protocol was validated by comparing those two conditions: 3 IDs and 11 IDs. This clinical protocol was also adjusted to test patients with ROM from 20 degrees to 40 degrees and above. This final short experimental protocol can be used to evaluate the neuromuscular performance of LBP patients with a minimal discomfort.
Psychophysiological Effects of Extended Workshifts
Authors: Duchon James C. , Smith Thomas J. , Keran Christopher M. , Koehler Eric J.
Published: January 2012

Working extended workshifts has been linked to decrements in behavioral performance and physiological function, plus subjective complaints. This report describes findings before and after workers in an underground mine converted from a continuous 8-hour to a 12-hour rotating shift schedule. A psychophysiological approach to work schedule evaluation was employed, involving continuous heart rate (HR) recording accompanied by pre-, mid-, and post-shift measures of cognitive and psychomotor behavioral performance, HR recovery and estimated VO2max levels using submaximal exercise testing, and subjective mood and sleepiness responses. The continuous HR results suggest adaptation of work effort or output on 12-h relative to 8-h shifts. Some measures of performance, namely self-report mood and sleepiness responses plus HR recovery, suggest more fatigue on 12-h shifts. We conclude that working extended workshifts may result in an adaptive response to fatigue, manifest in the form of pacing or modulated work effort by the workforce.
Audibility Problems with Fire Alarms in Apartment Buildings
Authors: Proulx Guylène , Laroche Chantal , Latour John C.
Published: January 2012

A previous study of apartment building evacuation drills showed that as many as 25% of the occupants mentioned not hearing the fire alarm from inside their apartments. A new experiment was developed to observe evacuation drills and to measure the sound level of the fire alarms in three high-rise apartment buildings. These buildings, built during the 1980's, met the local building regulations regarding the provision of fire alarms at the time of construction. Each building contained approximately 200 apartments, with 1 to 4 persons per apartment. For each building, the printed fire safety procedures stated that all occupants should leave the building or move to an area of refuge, upon hearing the building fire alarm.

During each evacuation drill, video cameras, were located in corridors and staircases, to record the movement time and behaviour of occupants. Using a digital audio tape recorder, precise sound samples of the fire alarm and background noise were taken from different locations in the buildings. Analyses of the alarm sound spectrum and levels were performed. Results confirm the subjective assessment of occupants who mentioned not hearing the fire alarm in specific locations of the building. It was also found that, in some other areas, the alarm was overpowering. The impact of alarm audibility on fire safety is discussed.