bluuebunny/crossref_metadata_2025 huggingface dataset:
Improving the Effectiveness of Configural Displays through Mapped Emergent Features and Color-Coded Graphical Elements
Authors: Bennett Kevin B. , Toms Mona L.
Published: January 2012

When completing tasks in complex, dynamic domains individuals must consider both high-level issues (e.g., relationships among several variables) and low-level data (e.g., the values of individual variables). An important issue in display design is to determine those graphic forms that allow the efficient extraction of information at both levels. One display that has the potential to achieve these dual design goals is the configural (object) display. Research on configural displays has indicated that this type of display will facilitate the extraction of information about high-level issues if the emergent features directly correspond to the critical data relationships that exist in a domain. On the other hand, designing configural displays to offset the cost that is usually associated with the extraction of low-level data has proven to be more difficult. One potential design strategy to accomplish this is to increase the perceptual salience of the lower-level display elements and color-coding is one technique to acheive this. Performance for color-coded configural and separate displays was compared in two empirical investigations. For the extraction of information regarding high-level issues the configural display significantly increased accuracy with no cost in latency. For the extraction of low-level data there were no differences between the configural and separate display for accuracy, but there was a significant decrement in latency associated with the configural display. However, the results indicate that this decrement in performance dissipates with experience, and under certain conditions was not significant.
Egocentric and Exocentric Displays for Terminal Area Navigation
Authors: Wickens Christopher D. , Liang Chia-Chin , Prevett Tyler , Olmos Oscar
Published: January 2012

Two experiments are reported that contrast egocentric vs. exocentric features of perspective (3D) or plan view (2D) electronic map displays for supporting local guidance and global awareness. Pilots used these displays for a simulated approach to a landing along a curved approach, through a terrain-filled region. The task was simulated on an IRIS visual graphics workstation. In Experiment 1, a rotating vs. fixed-map display was experimentally crossed with a 2D vs. 3D (perspective map) view as 24 pilots were assessed in their ability to maintain the flight path (local guidance) and demonstrate global awareness of surrounding terrain features. Rotating displays supported better flight path guidance in both the lateral and vertical axes, and did not substantially harm performance on the task of recalling the location of terrain features. Map rotation also supported better performance in locating features from an ego-referenced but not a world-referenced perspective. 3D displays provided a slight advantage for lateral guidance but a substantial cost for vertical control, because of the ambiguity with which perspective viewing depicted precise altitude. In Experiment 2, 10 pilots flew with the rotating 2D display, and with an improved version of the rotating 3D display, using color coding to reduce the ambiguity of altitude information. Vertical control improved as a result of the 3D display design improvement, but lateral control did not. Assessment of terrain awareness on a map reconstruction task revealed marginally better performance with the 2D map. The results are discussed in terms of the costs and benefits of presenting information in 3D, ego-referenced format for both local guidance and global awareness tasks.
A Study of the Effects of Repeated 36-Hour Simulated Missions on B-1B Aircrew Members
Authors: Neville Kelly J. , Bisson Roger U. , French Jonathan , Martinez Johnnie , Storm William F.
Published: January 2012

The military goal of Global Reach - Global Power entails an unprecedented dependence on immediate and sustained long range bombing campaigns. This research effort was initiated to evaluate the feasibility of this type of long range operation by studying the effects of multiple long duration missions on bomber aircrews. Measures of cognitive performance, mood, fatigue, and sleep management suggest that crews learned to adapt to the missions. However, cognitive performance deteriorated during the early morning hours of each mission and expert ratings of flight deck performance suggest that some components of performance may have been negatively impacted by the repeated missions. This research contributes to the base of information that may be used to make operational risk decisions and suggests ways to reduce schedule-related risks. It also explores the effects of sustained operations on complex tasks, as well as on simple tasks, and explores the use of multiple data collection techniques in a non-laboratory setting.
Situation Awareness Information Requirements Analysis for En Route Air Traffic Control
Authors: Endsley Mica R. , Rodgers Mark D.
Published: January 2012

Situation awareness is a fundamental requirement for effective air traffic control forming the basis for controller decision making and performance. To develop a better understanding of the role of situation awareness in air traffic control, an analysis was performed to determine the specific situation awareness requirements for air traffic control. This was conducted as a goal-direct task analysis in which the major goals, subgoals, decisions and associated situation awareness requirements for En Route Air Traffic Control (ATC) were delineated based on elicitation from eight experienced Air Traffic Control Specialists. This effort was supported by available task analyses and video-tapes of simulated air traffic control tasks. A determination of the major situation awareness requirements for En Route ATC was developed from this analysis, providing a foundation for future system development which seeks to enhance controller situation awareness and provides a basis for the development of situation awareness measures for air traffic control.
Introducing a Practical Human Factors Guide into the Aviation Maintenance Environment
Authors: Maddox Michael E.
Published: January 2012

A safe and efficient air travel system depends on three elements; design, operation, and maintenance. The Human Factors profession essentially began and matured in the aviation environment. The aircraft cockpit and the skills involved in piloting have been the subjects of more human factors research than any other single topic. Likewise, the topic of aircraft design has been the beneficiary of many of the tools and procedures developed to embed human capabilities into products. The third component, maintenance, seems to receive attention only when it is shown to be a contributing factor in a mishap. In an effort to embed proper human factors principles in the aircraft maintenance environment, Congress, through the Federal Aviation Administration Office of Aviation Medicine (OAM), has mandated that more emphasis be placed on human factors in maintenance operations. A major product of this initiative is a Human Factors Guide, being developed to provide practical, useful, and usable guidance to supervisors and planners in the aviation maintenance industry. This paper describes the goals, form, and content of the new Human Factors Guide.
Ergonomics on the Hangar Floor: Structuring the Intervention Process
Authors: Drury Colin G.
Published: January 2012

A methodology is demonstrated which systematically interpreted aircraft inspection tasks in human factors terms, performed projects where human/system mismatches were found, and re-integrated the project findings to provide for comprehensive intervention. A generic function description was first used to structure extensive hangar-floor observations and analysis, and potential mismatches determined. Projects were completed for each function, for example redesigned workcards for the Initiate function and lighting studies for the Search function. Integrative techniques developed were a computer-based audit program to evaluate human factors in aircraft inspection tasks, and a systematic implementation technique based on human factors teams in the hangar.
Applying Virtual Environment Technology to the Design of Fighter Aircraft Cockpits: Pilot Performance and Situation Awareness in a Simulated Air Combat Task
Authors: Hettinger Lawrence J. , Nelson W. Todd , Haas Michael W.
Published: January 2012

The use of multi-sensory displays for fighter aircraft cockpits is being investigated at the U.S. Air Force's Armstrong Laboratory as a means of enhancing pilot performance. The current experiment was conducted to evaluate the effect of employing such displays on the performance of a simulated air combat task. Each of four experienced US Air Force F-16 pilots flew 12 simulated missions which required them to locate and destroy four enemy bombers whose flight path was pre-programmed. Simultaneously, two other pilots were assigned to auxiliary cockpits in the laboratory and flew enemy fighter aircraft in an attempt to intercept and shoot down the primary pilot. Therefore there were three active participants in each air combat scenario. Each pilot flew six trials using a cockpit comprised of conventional F-15 flight instruments and six trials using a modified, multi-sensory cockpit. The results indicated that pilot performance and situation awareness were generally superior with the multi-sensory cockpit as opposed to the conventional cockpit, although statistical differences between the two were at best marginally significant. Nevertheless, the results suggest that if pilots were to receive advance training with the multi-sensory cockpit their performance may exceed that in the highly overlearned conventional cockpit by even more substantial amounts.
Development of a Speech Analysis Protocol for Accident Investigation
Authors: Mayer David L. , Brenner Malcolm , Cash James R.
Published: January 2012

This paper describes an initial attempt to develop a protocol for speech analysis techniques that might lead to a better understanding of the cognitive and emotional states that underlie the behavior of people involved in accidents. A tape recording of radio transmissions made by a pilot during both routine and emergency flight conditions was analyzed. Five primary speech measures were made for each statement: mean fundamental frequency (f0), range of fundamental frequencies (Δf0), duration, mean amplitude and syllable count. Speaking rate (syllables per second) and two other derived measures were computed later. During routine flight, the pilot's f0 averaged 123.9 Hz, but this increased to an average of 200.1 Hz during emergency conditions. Range of f0 also increased significantly, while syllable count decreased. These changes may provide a profile of a response to extreme stress that may be useful for gaining insight into situations in which such stress is not otherwise apparent.
Audible Performance of Smoke Alarm Sounds
Authors: Huey Richard W. , Buckley Dawn S. , Lerner Neil D.
Published: January 2012

This paper concerns a study aimed at selection of alarm sounds with improved audible performance characteristics for older listeners over current conventional residential smoke detectors. Many current residential smoke detectors possess alarms that have their primary frequency peak in the 4000 Hz region of the audible spectrum. Additionally, many of these alarms are constant instead of providing temporal modulation of the signal. This study analyzed a variety of alternative sounds for selection as a better choice for an “age sensitive” smoke alarm signal. The study presented a battery of candidate sounds to pairs of subjects aged 65 and older with varying levels of hearing impairment (0 to 45 dB) in their own homes to see which sounds performed best in terms of detection, localization, and perceived attention-getting value. Subjects were placed in various location- and masking-based conditions within their homes during listening periods and subjected to sounds played at a constant level. A computerized system collected response data as the battery of stimuli was presented. The data showed a fairly predictable positive trend in detection and localization performance level as the frequency of the stimuli decreased from 4000 Hz to 500 Hz. The data also showed that pulsed signals were more detectable than steady alarms.
Memory Skill Acquisition for Young and Old Adults: Does Training Order Affect Learning?
Authors: Clark Jennifer L. , Rogers Wendy A.
Published: January 2012

The purpose of the present experiment was to identify the effects of altering the order of training for a memory search task in old and young adults. We provided subjects with extensive practice on consistently mapped (CM) and variably mapped (VM) versions of a memory search task. Half of the subjects in each age group received CM training followed by VM training and the other half received VM first followed by CM. Based on previous findings (Fisk, Rogers, and Giambra, 1990), in which older adults did not switch to a more efficient search strategy (i. e., from serial exhaustive to serial self-terminating) we predicted that older subjects who received VM training first would not adopt the most efficient strategy on subsequent CM training compared to old adults who received the CM training first. The results supported our prediction: namely, the comparison slopes were shallower (i. e., more efficient) for the older adults who received CM training first, relative to those who received VM training prior to the CM training. Order of practice did not significantly affect the performance of the young adults. These data have important implications for the development of training programs in which subjects will be required to learn several task components.
Cooperative Human-Computer Decision Making: An Experiment and Some Design Implications
Authors: Sundström Gunilla A. , Salvador Anthony C.
Published: January 2012

Creating useful dialogues between human and automated decision makers (i.e., intelligent agents) is a critical design aspect of any effective decision support environment. However, surprisingly few studies have examined the various factors influencing the way a human decision maker interacts with various types of intelligent agents. In the present work, one such factor was examined, namely the confidence expressed by the agent about its own conclusions. Subjects were trained in a network management fault diagnosis task. They were then asked to accept or reject a fault diagnosis generated by the automated decision making agent. The automated decision maker presented its fault diagnosis with an associated confidence indication expressed as a probability. Subjects were required to decide whether to accept or reject the automated decision maker's diagnosis. To conceive an informed response, subjects were able to examine various types of information related to network performance. The results indicated that the higher the confidence level presented by the automated decision maker, the more likely it was that the human decision maker would accept the automatically generated diagnosis. Thus, the higher the confidence level of the automated decision maker, the more likely subjects were to accept a wrong decision. Moreover, subjects examined fewer pieces of information in situations when the automated decision maker expressed a high level of confidence.
Navigating on the Information Highway
Authors: Lund Arnold M.
Published: January 2012

The “information highway” is being created now, and the design task is monumental. Some of the most critical problems in designing a navigation environment have never been addressed before, and developers are demanding that either we (as human interface designers) supply answers now or they will make up their own answers. There is too little time and there are too few resources to fully explore interesting theoretical issues, and yet the results of such exploration (if on the right topics) could be critically important. This paper will review some of the practical design issues that Ameritech has identified as being important in defining a navigation environment, and approaches we have taken to those design issues. These approaches have been shaped by a lack of design guidance in some areas, and a finite set of resources (especially time). The paper will also identify directions where research would be useful, and time frames during which the results will still be valuable.
Virtual Reality as a Human Factors Design Analysis Tool for Architectural Spaces - Control Rooms to Space Stations II: Subjective Measures
Authors: Dittmar Mary Lynne , Hale Joseph P.
Published: January 2012

The Architectural Space Questionnaire (ASQ) was developed and employed in order to assess subjects' impressions of four different environments (two real and two virtual rooms) at the NASA Marshall Space Flight Center. The ASQ consists of 18 adjectivepairs, arrayed in a 7-point, Likert scale format. Subjects first participated in avariety of distance estimation tasks in the Spacelab Payload Control Room and the Simulation Control Room and in their virtual reality (VR) analogs. After their experience in each room, subjects responded to the ASQ, selecting one value on each adjective pair continuum which best described their impression of the room they were in. The results indicated that the ASQ is sensitive to structural differences between real rooms. Differences between virtual rooms were minimal., possibly due to the absence of visual cues such as lighting and texture in that environment. Implications for the use of VR as a design tool are explored.
A Componential Model of Human Interaction with Graphs. III. Spatial Orientation
Authors: Gillan Douglas J. , LaSalle S. Mark
Published: January 2012

The Mixed Arithmetic-Perceptual (MA-P) model of graph comprehension proposes that graph users apply combinations of component processes — including Searching for indicators, Encoding the value of indicators, performing Arithmetic Operations on the values, making Spatial Comparisons among the indicators, and Responding — when they answer questions from a graph. The model further suggests that the combination and order of the components that the user applies depends on a user's task and the type of graph. The present research investigated the use of another component process — mental rotation — in interacting with star graphs. Subjects used two star graphs to answer comparison and difference questions in which the differences in orientation of the indicators in question varied from 0 to 288°. The results showed a nonmonotonic change in response time with the difference in orientation. The discussion addresses the effects of mental rotation in reading displays and the role that rotation may play in the hierarchy of graph effectiveness proposed by Cleveland and McGill.
The Development and Evaluation of the Keybowl: A Study on an Ergonomically Designed Alphanumeric Input Device
Authors: McAlindon Peter Joseph
Published: January 2012

This paper provides a description and discloses preliminary findings of a newly designed alphanumeric keyboard called the Keybowl. The Keybowl was designed and developed to provide a solution to the multi-million dollar a year problem of Carpal Tunnel Syndrome (CTS) as it relates to typing. The Keybowl totally eliminates finger movement, minimizes wrist movement, and uses the concept of concurrent independent inputs (a.k.a. chording) in which two domes are moved laterally to type. Initial results indicate that users of the Keybowl typed an average of 52% of their regular keyboard speed in as little as five hours. In regard to ergonomic advantage, flexion/extension wrist movements have been reduced by an average of 81.5% while movements in the ulnar/radial plane were reduced by an average of 48%.
Measuring Perceived Task Difficulty Using Magnitude Estimation: A Demonstration and Replication
Authors: Alteras-Webb Sabina , Dekker Debra K.
Published: January 2012

The proliferation of sedentary, more cognitively demanding computer-mediated work, calls attention to the need for methods to measure mental work load. The present research describes two experiments in which participants performed a machine paced task of entering five and/or nine digit zip codes into a computer. The zip code data was presented on a computer screen for twelve four minute trials where the rate of zip code presentation varied from trial to trial. Using the psychophysical scaling method of magnitude estimation, participants made a judgment of task difficulty after each trial period. In Experiment 1, four females participated in a repeated measures within-subjects design performing each digit task condition for five consecutive days. In Experiment 2, a between-subjects design was adopted where 42 females performed either the five or the nine digit data-entry for only one testing session. Regression analyses using the independent variable of stimulus presentation rate and the dependent variable of judgments of perceived difficulty resulted in R2s of .90 or better for both digit conditions in both experiments. T-tests were conducted to see if different task parameters would affect difficulty judgments; these were statistically significant to the .001 level in both experiments. The results support the notion that magnitude estimation is a reliable method for scaling subjective perceptions of difficulty, which may be an important component of mental workload.
Electronic Resources for Human Factors and Ergonomics Education: Lessons from Human-Computer Interaction
Authors: Perlman Gary
Published: January 2012

I describe four electronic educational resources available via computer networks and electronic mail: (1) a curriculum module on user interface development; (2) a bibliography on human-computer interaction; (3) a description of courses and curricula in human-computer interaction, and (4) a survey of educational opportunities in human-computer interaction. For each of these, I discuss: (1) why the resource was created, (2) how the information was gathered, (3) what information has been gathered, (4) how to access the information, (5) how it has been used in HCI education, and (6) how the information (or information like it) can be applied to Human Factors and Ergonomics (HF/E) education. I conclude with recommendations for the modernization of HF/E information infrastructure.
Participatory Ergonomics as a Means of Preventing Wmsds
Authors: Brown Ogden
Published: January 2012

Participatory ergonomics is a flexible means for the achievement of many diverse goals in turbulent technological environments. It is a macroergonomic approach to the implementation of technology in organizational systems which requires that end-users be highly involved in developing and implementing the technology. The notion of participation offers the promise of tremendous potential gains for the organization, the worker, and even the economic well-being of the greater society.

Such pervasive and important technological innovations as the use of computers and their concomitant video display terminals can, in spite of their usefulness, lead to many occupational health and safety problems. Cumulative trauma disorders appear to be an associated dysfunction in modern industry, and effective health and safety solutions to many of these problems are highly important, both to the organization and especially to the people in it. It is proposed that the use of participation and worker involvement in the solution of such problems is a powerful and promising tool.

There is no one best way to employ worker participation. It is contingent upon the nature of the problem itself, the work system, the job design presently in place, the environment in which the work is done, the training of the worker, and a myriad of other variables.

From the available empirical evidence, a participation typology is postulated. The successful implementation of participatory ergonomics and other participatory arrangements requires the empowerment and enablement of people to make decisions concerning their work and to implement and evaluate them.

Several participatory approaches to worker involvement are presented which address work system and job design factors, design of the work environment, and training of VDT operators. These approaches are discussed in the context of a systems approach to the prevention of WMSDs.

The reduction and/or prevention of cumulative trauma disorders such as work-related musculoskeletal disorders is a matter of great concern in modern organizational life, both from the point of view of productivity concerns and also from that of the humanization of work. The solution of occupational health and safety problems will not only lead to increased organizational effectiveness, but should help provide for a far better realization of human potential.
The Understandability of Legal Documents: Are they Adequate?
Authors: Howe Julie E. , Wogalter Michael S.
Published: January 2012

Citizens are frequently asked to make commitments by signing contracts and legal documents that frequently contain phraseology and jargon (sometimes called legalese) that highly-educated citizens often do not understand. In recent years, human factors professionals have become intimately concerned with the design of product-related documentation and safety communications (e.g., warnings), and through research have offered ways to improve these materials. However, there is apparently no human factors research on the design and evaluation of legal contracts and other similar documents. The purpose of the present research was to begin to assess some of the factors related to people's reading and understanding of legal documents. Study 1 examined the types of legal documents that people sign, how often they sign them, how carefully they read them, and whether they understand them. Ninety-two individuals were asked to complete a survey addressing these issues. While it was reported that the contracts were read moderately carefully and were understood moderately well, the levels were not as high as one would expect given the importance of the documents and the education level of the participants in this study (who had, on average, approximately two years of college). Also, 96% of the sample believed that legal documents could be improved and provided specific suggestions on how this might be accomplished. In Study 2, 32 participants rated the set of potential improvements to legal documents that had been suggested by Study 1's participants. The results confirmed the first study's pattern of findings. Implications for average citizens' lack of comprehension of contracts and other legal documents are discussed with a specific focus on the role research might have on their improvement.
Human Factors Studies to Investigate Driver Behavior under In-Vehicle Information Systems: An Interactive Microcomputer Simulation Approach
Authors: Adler Jeffrey L. , Kalsher Michael J.
Published: January 2012

In-vehicle traveler information systems are being designed to provide drivers with real-time route guidance and/or traffic advisory information. It is expected that these Advanced Traveler Information Systems (ATIS) technologies will have a major impact on travel efficiency by assisting drivers to make better real-time route choices in response to changing network conditions. There is not yet full knowledge as to the impacts that route guidance and traffic advisory systems will have on driver behavior. This paper presents preliminary results from a human factors experiment to investigate the effects of traffic advisory and route guidance information on enroute behavior and travel performance. An interactive microcomputer simulation was used for data collection. The study suggests that both drivers' route choice efficiency and understanding of network conditions can be improved with access to real-time traffic advisory and route guidance information.
A Direct Perception Interface for Nuclear Power Plants
Authors: Moray Neville , Lee John , Vicente Kim J. , Jones Barclay G. , Rasmussen Jens
Published: January 2012

Following the suggestions of Beltracchi (1987) a direct perception interface for the thermal hydraulic systems of a pressurized water nuclear power reactor (PWR) was developed. It presents operators with an animated graphic of the Rankine heat cycle describing the functional relations of steam generation in a PWR. The ability of students of thermal and nuclear systems to recall system states, and detect and diagnose nine transients was compared to that of experienced nuclear power plant operators. The results were compared to a display representing traditional analog meters. The direct perception interface supported better diagnostic performance, but did not improve memory for quantitative information. Problems in evaluating such displays are discussed, in particular concerning choice of scenarios, and investigation of failure modes of advanced displays.
A Double Edge Sword: Compensatory Behavior in Coping with System Malfunctions
Authors: Gopher Daniel , Weil Maya , Erev Ido
Published: January 2012

Malfunctions and minor technical problems in system operation are not a rare event when humans interact with engineering systems. When a problem is detected, the system should, in principle, be halted and repaired. Often, however, operators decide to continue their work and adopt alternative modes of behavior that bypass or compensate for the malfunctions. We label this type of responses “compensatory behaviors”. They are adopted because the operator judges them to be less costly than the costs involved in stopping and repairing the system. Twenty Subjects, had four sessions of training, with a simulated filling work station in a chemical plant, where 8 simultaneous tanks had to be filled with lethal solutions. Malfunctions in the automatic filling regulator of one of the tanks, occurred intermittently, resulting in two types of risks: a high risk failure could explode the entire system at the cost of 200 points; a low risk failure could lead to a defective container, translated to a loss of 10 points. Subjects could resolve to shut down the station for repair at the cost of 100 points, or switch the failed tank to manual and stop the filling when the liquid reached the required volume. Their ultimate goal was to achieve the highest score possible. Results showed significant preference for compensatory behavior over repair, in all stages of skill acquisition and at all levels of potential risk. When adopting compensatory behavior, subjects' decision, attention and main efforts seem to have been exclusively guided by their ability to avoid the occurrence of explosions. The number of explosions was indeed reduced, although not eliminated, with training. At the same time, and in contrast with their belief, subjects slowed down their production rate, had more errors and more defective containers. Thus the total cost of compensatory behavior was higher than the costs of repairing the system. This is the double edge sword of compensatory behavior. The selective focus on direct costs and the neglect of indirect costs, have important implications to decision behavior research and skill acquisition, as well as practical implications to the development of training programs and work procedures.
Age and Glare Recovery Time for Low-Contrast Stimuli
Authors: Schieber Frank
Published: January 2012

The purpose of this study was to obtain a rigorous experimental estimate of the time required to recover from the deleterious effects of glare. Low contrast test stimuli were employed to increase the potential sensitivity of the procedure. Multiple age groups were sampled since susceptibility to glare effects is known to increase with advancing years. Glare recovery time assessments were collected from 12 young, 12 middle-aged and 16 older adults. Subjects were presented with 10 sec exposures to an intense glare source under highly controlled experimental conditions. Upon the offset of the glare exposure period, the time required to regain sensitivity for low contrast test stimuli was measured. Relative to their younger counterparts, older subjects required 3-times longer to recover from glare exposure. These findings suggest that the dynamic components of glare effects must be considered when designing environments - especially where older observers are involved.
The Effects of a Stretcher-Carry Harness on Soldier Performance: Carrying from a Remote Area
Authors: Rice J. B. , Tharion William J. , Sharp Marilyn A.
Published: January 2012

This study investigated whether the use of a shoulder harness and team size would affect stretcher-carry performance and post-carry rifle marksmanship and fine-motor coordination following a carry from a remote site. Soldiers (12 male and 11 female) carried stretchers in two-and four-person teams, with and without a shoulder harness. Soldiers carried a stretcher at 4.8 km/hr for as long as possible, up to 30 min. Soldiers fired at targets and completed a fine-motor coordination task before and after each carry. Analysis of Variance and post-hoc Newman-Keuls Comparison of Means revealed significant rifle shooting impairments after stretcher-carrying (p < 0.001). Men carried the stretcher longer than women (p < 0.0001). Harness use and carrying in four-person teams prolonged carry time for both men and women, without decreasing shooting accuracy. Completion of a fine-motor coordination task was faster after using a harness vs a hand carry (p = 0.03) and working in four vs two-person teams (p < 0.02). Heart rate was lower during harness carries (p < 0.001). In conclusion, the ability to transport, medically treat, and protect patients is improved by harness use and working in four-person teams. It is suggested the policy of using four-person teams be enforced, and harness systems be included with the supply of stretchers for any situation that requires continuous stretcher-carrying of five minutes for four-person teams or two minutes for two-person teams.
Strength Capabilities While Performing Torquing Tasks in Weightlessness
Authors: Poliner Jeff , Wilmington Robert P. , Klute Glenn K.
Published: January 2012

Knowledge of individuals' strength capabilities in weightlessness is of interest within many areas of NASA, including workplace design, tool development, and mission planning. This study was a generic examination of the loads produced by individuals performing maximal efforts with a torquing tool in zero-gravity. The study also examined the effects of orientation and direction of rotation of the tool on strength effectiveness. An experiment was conducted aboard NASA's reduced gravity aircraft which simulates brief periods of weightlessness. A test stand was developed and instrumented to measure the loads applied to fixed fittings. Eight male volunteers participated in this study in which they used a wrench to apply a maximum torque to fittings oriented along each of three orthogonal axes. It was seen that these subjects could produce approximately 400 to 750 N of force, depending on the orientation of the tool and the direction of effort. The most force could be produced when pushing the tool upwards. A force effectiveness ratio (FER) was defined as an indication of how much of the subject's total effort actually went into performing the desired task. Values of FER ranged from 0.55 to 0.90, with the greatest FER occurring with UP and DOWN efforts, and the lowest with AWAY and LEFT efforts. Designers can use these results to set specifications for craft structures; tools can be developed based on the known strength of the tool users; and tasks can be developed to not exceed the crewmembers' capabilities.
Tactility as a Function of Grasp Force: Effects of Glove, Orientation, Load and Handle
Authors: Bishu Ram R. , Bronkema Lisa A. , Garcia Dishayne , Klute Glenn , Rajulu Sudhakar
Published: January 2012

The objectives of this research were to ensure that a reduction in tactile sensitivity was causing a reduction in gloved performance, and to measure this reduction in tactile sensitivity through grasp force at the hand/handle interface under a variety of performance conditions. The effects of glove type, load lifted, handle size, and handle orientation on the initial grasping force and stable grasping force were determined through a factorial experiment in which 10 subjects participated. The working hypothesis was that grasp force would be a function of all the above mentioned factors. The most consistent findings of this experiment were:

1. Glove effect is marginal at submaximal exertions. 2. The magnitude of force exertions in the advanced glove and bare handed conditions were similar. 3. The magnitude of force exertion was the highest with meat packing gloves. 4. The ratio of peak to stable grasp force increased with increasing loads. 5. The glove effect for maximal exertions as seen in experiment 2 is consistent with published evidence.

In conclusion, it is clear from these experiments that when people perform a grasping action, the maximal exertions are affected differently by gloves than sub-maximal or “just holding type of exertions.”
Dynamics of Power Hand Tools on Operator Hand and Arm Stability
Authors: Oh Seoungyeon , Radwin Robert G.
Published: January 2012

Threaded fastener tightening was studied to determine effects of tool dynamics (torque and build-up time) and workstation configuration (orientation, horizontal distance and height) on operator kinematics and ability to stabilize a right-angle power hand tool. Hand velocity, hand displacement, tool torque, and spindle angle were recorded during tool operation. Four subjects participated. Workstation factors and tool dynamics had significant effects on hand stability. The magnitude of hand velocity and displacement was significantly greater for (1) vertical work surfaces compared to horizontal work surfaces; (2) vertical work surfaces higher than 90 cm above the ground; (3) horizontal work surfaces 90 cm above the ground; (4) increasing torque levels, and (5) long torque build-up times. Subjective ratings of perceived exertion were greater for increasing torque levels, long build-up times, and increasing workstation heights. Perceived exertion was significantly related to hand velocity and displacement ( p<0.05), however, the strength of the correlation was small (R2 ranged between 0.01 and 0.10).
The Effects of Different forms of Space Restriction on Inspection Performance
Authors: Reynolds J. L. , Drury C. G. , Sharit J. , Cerny F.
Published: January 2012

Work in restrictive spaces is characteristic of many tasks, particularly in maintenance and inspection operations. The nature of the spatial restriction as well as its magnitude is likely to affect the worker's response to the space. This research measured the effects of three different spatial restrictions (vertical (V), sagittal (S) and combined (VS)) on an inspection task. The effects of the three restrictions on postural adaptation, physiological response, psychophysical reports and task performance were qualitatively different. Generally, the VS and V restrictions caused increases in operator stress and workload, with these effects being most severe under the VS restriction. Conversely, the S restriction caused no increases in operator stress and tended to improve performance. Thus, while restrictions are generally detrimental, certain mild restrictions may actually facilitate jobs.
Psychophysical Cost Function of Joint Movement for Arm Reach Posture Prediction
Authors: Jung Eui S. , Choe Jaeho , Kim Sung H.
Published: January 2012

A man model can be used as an effective tool to design ergonomically sound products and workplaces, and subsequently evaluate them properly. For a man model to be truly useful, it must be integrated with a posture prediction model which should be capable of representing the human arm reach posture in the context of equipments and workspaces. Since the human movement possesses redundant degrees of freedom, accurate representation or prediction of human movement was known to be a difficult problem. To solve this redundancy problem, a psychophysical cost function was suggested in this study which defines a cost value for each joint movement angle. The psychophysical cost function developed integrates the psychophysical discomfort of joints and the joint range availability concept which has been used for redundant arm manipulation in robotics to predict the arm reach posture. To properly predict an arm reach posture, an arm reach posture prediction model was then developed in which a posture configuration that provides the minimum total cost is chosen. The predictivity of the psychophysical cost function was compared with that of the biomechanical cost function which is based on the minimization of joint torque. Here, the human body is regarded as a two-dimensional multi-link system which consists of four links; trunk, upper arm, lower arm and hand. Real reach postures were photographed from the subjects and were compared to the postures predicted by the model. Results showed that the postures predicted by the psychophysical cost function closely simulated human reach postures and the predictivity was more accurate than that by the biomechanical cost function.
The Economics of Ergonomics
Authors: Alexander David C.
Published: January 2012

The economics of ergonomics is important from a managerial and technical standpoint. This paper provides an overview of the economics of ergonomics, both from a conceptual standpoint and from a practical standpoint. The economics at the project level as well as economics at the program level are discussed. There are a number of possible techniques to use and the advantages and disadvantages of them are presented. Some techniques work better under some circumstances than under other circumstances. Finally, a short list of ways to control costs within an ergonomics program is provided.
Users as Designers: How People Cope with Poor HCI Design in Computer-Based Medical Devices
Authors: Obradovich Jodi Heintz , Woods David D.
Published: January 2012

In this paper, we examine how users interact with a computer-based infusion device adapted for terbutaline infusion to treat preterm labor in women experiencing high-risk pregnancies. This study examines: (1) the HCI deficiencies in the device as related to this context of use, (2) how the device characteristics increase the potential for error, and (3) the tailoring strategies developed by users to insulate themselves from failure. Interviews with nurses and bench tests of the behavior of the infusion device in different conditions identified several HCI deficiencies: complex and arbitrary sequences of operation, mode errors due to poor differentiation of multiple operating modes intended for different contexts, ambiguous alarms, getting lost in multiple displays, and poor feedback on device state and behavior.
The IEA and Ergonomics Internationally
Authors: Hendrick Hal W.
Published: January 2012

The conception, development and growth of the IEA and ergonomics internationally is reviewed. The current structure and functioning of the IEA is described. Recent activities of the IEA's two largest committees, Education and Training and Science and Technology, are summarized. A brief overview is provided of the IEA federated societies and current international ergonomics. With these data as background, the panelists will discuss current trends and issues within the IEA and ergonomics internationally.
Community Ergonomics: An Emerging Theory and Engineering Practice
Authors: Smith John H. , Smith Michael J.
Published: January 2012

The context and condition specific relationship of certain human populations and their communities to technology, the environment, and numerous interactions which contribute to conditions of economic-social alienation, are contributing negatively to community quality, productivity and work organization of the American city. The need is for systems methods to resolve and prevent the occurrence of negative design factors which contribute to disputes, conflict and social impairment of individuals and institutions. This paper will advance the practice of Community Ergonomics to improve human interactions, evolution, law, and in planning for positive organization of groups for self-regulation and control of community resources and work.
Community Ergonomics: Past Approaches and Future Prospects towards America's Urban Crisis
Authors: Cohen William J. , Smith John H.
Published: January 2012

The purpose of this paper is to examine past and current urban programs and to propose a new human engineering approach to solve entrenched problems. The application of a systematic engineering philosophy is central to a process that is focused around the concepts of work. As such, a new application of industrial engineering and human factors is proposed. The creation of stable, worthwhile jobs is crucial, but only in relation to an entire system which includes (among many others) existing governmental programs, educational systems, law enforcement, financial institutions, and especially, people's desires and needs towards bettering their lives. This approach is neither entirely governmental nor privatized. Private industry will be created and encouraged to utilize a non-traditional workforce. Benefits from governmental programs will be utilized to promote an entrepreneurial spirit that can succeed outside of the “underground economy”. In addition, efforts will be coordinated to help people become increasingly independent from hand-outs. The ultimate goal of community ergonomics is to reinvent the “fit” between people, their cities, and society. The development of people and jobs together is vital to this effort. In order for this approach to succeed, programs must propose both empirical research and practical applications.
Enhancing Comprehension and Retention of Safety-Related Pictorials
Authors: Brelsford John W. , Wogalter Michael S. , Scoggins James A.
Published: January 2012

Because of their relatively universal information transmission potential, pictorials have been suggested as a common means of safety communications across heterogeneous groups of users and uses. The present study used a training paradigm designed to enhance comprehension and retention of pharmaceutical and industrial-safety pictorials. Manipulated were time of testing (prior to training, immediately following training, and after a one-week delay), content of instruction (supplying the associated verbal label vs. the verbal label plus an extra explanatory statement), and difficulty level (“easy” vs. “difficult” to understand pictorials according to comprehension rates in earlier studies). Using an incomplete factorial mixed-model design experiment, the results showed substantial training effects. There was little change in scores between the test immediately after training and the test after a one-week delay (and the final test scores did not differ between participants who took or did not take the immediate post-training test). Easy pictorials were comprehended (both initially and following training) better than difficult pictorials, although the latter showed the most dramatic increase in understandability after training. Additionally, the instruction content manipulation (adding the explanatory statement to the verbal label)—which had been expected to influence the degree of encoding–had no effect on retention. The substantial gains in understanding the more difficult pictorials suggest that brief training, as little as giving the pictorial's verbal meaning once, can have a large impact in facilitating comprehension for pictorials that would otherwise not be understood by many people.