bluuebunny/crossref_metadata_2025 huggingface dataset:
The Proposed OSHA Standard Related to Ergonomics
Authors: Cochran David J. , Silverstein Barbara A. , Berkowitz Deborah , Worrell Gregory A. , Albin Thomas J. , Marras William R. , Armstrong Thomas J. , Brown Todd R.
Published: January 2012

This roundtable discussion will be devoted to the proposed OSHA Standard related to Ergonomics which is scheduled to be published the first week in October. The discussion will be timely and important. This is a very controversial topic. The participants have been selected from different backgrounds and opinions. Barbara Silverstein is the head of the standard writing team and is on leave at OSHA in Washington, D.C. from her regular employment with the State of Washington Department of Labor and Industries. Deborah Berkowitz is the Director of Safety and Health of a national labor union (United Food and Commercial Workers) and has been actively pushing for better ergonomic accommodation for workers. Gregory Worrell is the Corporate Ergonomics Director of a major meatpacking company (Monfort Inc.) and has extensive experience in establishing and conducting Ergonomics programs. Thomas Albin is a corporate level Ergonomist for 3M and is responsible for a considerable part of that company's Ergonomics effort and has extensive experience in establishing and conducting Ergonomics programs. Todd Brown is a Senior Research Engineer with the Association of American Railroads who has considerable experience in funding and conducting ergonomic research for application in the railroad environment. William Marras is a leading researcher and practitioner in the field of Ergonomics, Biomechanics, and Cumulative Trauma Disorders. Thomas Armstrong is a pioneer in the research and practice in the fields of Ergonomics and Biomechanics as they relate to Cumulative Trauma Disorders. These are talented, well respected people in their areas of expertise and will bring the latest thinking to this roundtable. This roundtable will not be a rehash of old stale ideas. The proposed standard is new and very important to the field of Ergonomics and to industry.
Age and Driver Time Requirements at Intersections
Authors: Lerner Neil
Published: January 2012

Current highway design models for required sight distance at stop-sign controlled intersections assume that the perception-reaction time (PRT) required is 2.0 seconds. That is, a 2.0 second interval to perceive, evaluate, decide, and initiate a response, is adequate to cover the range of time it takes real drivers to do this. This experiment evaluated the adequacy of the 2.0 second PRT assumption, including specific consideration of older drivers, who are known to experience relatively greater difficulty at intersections. Subjects in three age groups (20–40; 65–69; and 70+ years old) drove their own vehicles (fitted with a computer-controlled video-based data collection system) over a route that included 14 stop-controlled intersections. At each stop sign, they were required to make ratings of “road quality;” this broke visual search, and provided an opportunity for the experimenter to precisely define the initiation of search and the initiation of forward movement (thus defining PRT). The 2.0 second PRT assumption was found to work reasonably well for all age groups, and corresponded to roughly the 85th percentile PRT for all subjects. PRTs for older subjects were slightly (but significantly) briefer than for younger drivers. Reasons for not observing a slowing of intersection PRT with advancing age are discussed. The findings are also compared to gap acceptance data from another experiment. Even though the present experiment did not find objective evidence of older drivers requiring longer decision times, older subjects nonetheless demanded longer gaps in traffic in order to judge it safe to enter traffic.
Identifying Clumsy Automation at the Macro Level: Development of a Tool to Estimate Ship Staffing Requirements
Authors: Lee John D. , Morgan Jennifer
Published: January 2012

Automation promises increased operating efficiency and suggests the opportunity to reduce the number of people required to operate commercial ships safely; however, clumsy automation may degrade safety and performance, rather than enhance it. This paper distinguishes between clumsy automation at the macro level and clumsy automation at the micro level and discusses macro level issues. Specifically, macro level clumsy automation refers to the failure to consider the broad implications of automation induced crew reductions. Clumsy automation may reduce workload and facilitate crew reductions during routine sailing, but these crew reductions may leave the vessel more vulnerable to unacceptable workload peaks during unusual and emergency situations (fires, unscheduled maintenance, rough seas, reduced visibility). In these situations, tasks not accommodated by the automation may overwhelm a crew that has been reduced by the introduction of automation. Currently, no systematic procedure exists to estimate the changes that automation implies for staffing levels and skill requirements. Avoiding the effects of clumsy automation depends on identifying techniques to broaden the study of automation to include the effects on the entire crew during all phases of ship operation. This paper describes a computer-based tool to help identify potential overload situations that would be difficult to anticipate through intuitive assessments of how automation and other factors affect crew requirements.
Determining Legibility Distance for Highway Signs: Is the within Subject Variability Being Overlooked?
Authors: Greene Frances A. , Koppa Rodger J. , Zellner Ronald D. , Congleton Jerome J.
Published: January 2012

Laboratory studies of warning symbol signs have been shown to underestimate legibility distances by up to a factor of two when compared with field studies. However, this research suggests it is more than simply experimental setting contributing to disparity in research findings. Using a group of old and young drivers, six symbol signs were investigated in both settings. With six trials per sign, legibility distances, defined as the distance at which the sign is correctly identified from a menu, were collected.

Large within subject variability was discovered in both age groups. This variability led to alternative ways of defining the dependent variable equivalent to designs of past studies examining legibility distances of the same signs. Different results arose out of the subsets created. The consideration is not just should a field-based versus laboratory-based methodology be used. An argument is posed that recommended distances at which signs are placed must be determined from a “worst-case” scenario. This premise requires a reexamination of our research methodologies for determining placement of highway signs.
The Effect of Related and Unrelated Memory Loads on the Prerecognition Visual Processing of Traffic Signs
Authors: Avant Lloyd L. , Thieman Alice A. , O'Boyle Michael W.
Published: January 2012

Prerecognition visual processing of traffic signs was evaluated while subjects maintained one of four different types of memory load: low imageability nouns, traffic sign words, random shapes, or traffic sign shapes. Recall was uniformly high (mean=92%) and did not differ among groups. There was a highly significant interaction among groups (different memory loads), sign messages (Stop, Right, Left, Slow), and sign formats (symbol vs. word). Holding random shapes in memory eliminated prerecognition processing differences among sign messages for symbol format signs. However, for all other memory loads, differences among sign messages were significant. Tests across the memory load conditions for each format of each sign message showed that, for the Stop symbol, the Right symbol, and the Right word signs, the various memory load conditions produced no significant differences. For all other sign messages in both symbol and word format, there were significant differences among memory loads. In summary, these data show that the action message presented in traffic signs is being unconsciously processed within the first few milliseconds of visual processing, and that these operations involve unconscious activation of memory processes that store the meanings of various signs.
Cog-C: A Tool for Estimating Cognitive Complexity and the Need for Cognitive Task Analysis
Authors: DeVries Michael J. , Gordon Sallie E.
Published: January 2012

Task analysis is a methodology used during many different phases of system development. However, because many tasks involve complex cognitive processing, there is an increasing need for designers to perform cognitive task analysis. It is generally agreed that cognitive task analysis tends to be costly in terms of time and effort, and many designers ask how they would know when cognitive task analysis should be performed. This demonstration features a computer-based decision aid, Cog-C, to help designers answer this question. The software tool is based on the assumption that cognitive complexity is a major factor in determining when cognitive task analysis must be performed. The tool therefore helps the user determine the relative level of cognitive complexity for a set of tasks. It does this by (1) guiding the user in developing a task/subtask hierarchy, (2) guiding the subject matter expert in estimating the “amount” of various categories of knowledge required for subtask performance (e.g., concepts, rules, patterns, and strategies), and then (3) providing output including the number of steps required for task completion, standardized subscores showing the relative amounts of each knowledge category, an overall cognitive complexity score, and a general recommendation as to whether the task is a potential candidate for cognitive task analysis.
Distributed and Dangerous Training Challenges
Authors: Moses Franklin L.
Published: January 2012

The conduct of training using actual equipment in field settings can be costly and even dangerous. This particularly is true for military missions such as air-ground (i.e., Close air Support) training. However, it also is true for training to fight fires, respond to disasters, control riots, and so on. This special session provides a demonstration and discussion about using simulation and simulators to supplement field practice. It points-the-way for realistic distributed training of dangerous missions.
Evaluation of Half-Mask Gas Collection for Metabolic Measurement in the Work Place
Authors: Farley Richard S. , Bishop Phillip A. , Ray Paul
Published: January 2012

Metabolic measurement is often important in job design and research. Metabolic measurement via indirect spirometry has traditionally used a mouth-piece nose-clip headgear (MNH) method of collecting expired gases. MNH is often uncomfortable, prohibits oral communication, may fail because of loss of nose-clip, and may interfere with or alter some work tasks because of the awkwardness of the headgear. Gas collection masks (MASK) offer the possibility of partially or totally alleviating the problems of MNH but increase the possibility of erroneous measure due to leakage. This study compared the measurement of performance and subject's subjective ratings of a typical MNH vs. MASK (Hans Rudolph model 8900 series) over a range of work loads from light to maximal in 20 well-trained subjects (M=12, F=8). Ventilation (Ve), oxygen uptake (VO2), and respiratory exchange ratio (RER) were collected with a Sensormedics MMC-1, and heart rate (HR) with a Polar Heartwatch. Comfort was assessed with a Likert questionnaire. Results from the final work rate are shown below:

Variable Ve (L/min) VO2 (ml/kg/min) RER HR (bpm)

MNH 105,217 52.2 1.13 187

MASK 115,281 56.6 1.09 187

Results show this MASK produced values as high as the MNH with greater subject comfort at both peak and sub-maximal work. The observed Ve in the MASK condition suggests that leakage was not problematic and there could be a tendency for the MNH to actually impede the measurement. Based on previous preliminary studies and these data, careful use of the MASK is recommended over MNH for work place metabolic or other ventilatory measurements.
Information Categorization for BMD Command and Control
Authors: Knapp Beverly G. , Ensing Annette R. , Coury Bruce G. , Godfrey Scott L.
Published: January 2012

Information requirements were investigated for operators in two BMD C2 (Ballistic Missile Defense Command and Control) Centers—command level and operations level. The objective was to elicit their underlying perceptions and cognitive structure of incoming data items, to address information display and decision support design requirements. Experts judged information items using an unconstrained sorting task, and data were analyzed using multivariate scaling methods. Findings revealed differences between the two groups in clustering of and associations between information items; e.g., more complex associations were found for the command level center. Also, the utility of the scaling algorithms for the large data sets used was assessed.
Ecological Validity in Laboratory Based Usability Evaluations
Authors: Jordan Patrick W. , Thomas D. Bruce
Published: January 2012

An interview based survey, looking at the suitability of a laboratory facility for usability testing, raised the issue of ‘ecological validity’. Ecological validity refers to the extent to which the test environment mirrors the environment in which a product would be used in ‘real life’.

Ten ergonomists, nine of whom used the laboratory, were interviewed. Opinions of the laboratory were generally positive; indeed there was a consensus as to the high value of the facility in the ergonomists' work. However, only one of those asked felt that the laboratory provided an ecologically valid testing environment. Initially, this result seems surprising; if the conditions don't provide ecological validity, this would appear to be a limitation on the laboratory's value.

This paper considers the concept of ecological validity; discussing the contexts in which it is important and those in which it is not a priority. The extent to which it can be achieved in the laboratory and how it could be achieved are also considered. Generally, the ergonomists were fairly pessimistic about the prospects for this.

All, bar one, of the ergonomists interviewed also conducted studies outside of the laboratory. The part played by ecological validity in deciding to evaluate in the field is discussed; at what point does the issue become important enough to force evaluations outside of the laboratory?

Five non-ergonomists from the same organisation were also interviewed. Interestingly, they seemed to give ecological validity a higher priority than ergonomists, in terms of influencing the overall value of an evaluation. They were also more inclined to expect ecological validity to be achievable in the laboratory — by using furniture to create an appropriate range of scenarios. This suggests that, even if scenario creation has no real effect on ecological validity (this was the opinion of many of the ergonomists), it may bring ‘propaganda’ benefits in terms of influencing commissioners' attitudes towards ergonomists' work.
Behavioral Control Characteristics of Performance under Feedback Delay
Authors: Keran Christopher M. , Smith Thomas J. , Koehler Eric J. , Mathison Peter K.
Published: January 2012

As part of a larger research project dealing with technological change, the U.S. Bureau of Mines has initiated a study of the nature and sources of variability in human performance during teleoperation. One important source of performance degradation during remote work is delay in sensory feedback from the remote site to the operator during task execution, caused by such factors as transmission and signal processing lags or inertia/momentum properties of large equipment. To investigate the properties of the behavioral control system under delayed feedback conditions, the Bureau has implemented a pursuit tracking task during which delay is imposed as a continuously varying sinusoidal forcing function. Using 11 subjects, the dynamic characteristics of tracking performance were assessed across a range of variable delay frequencies. Specifically, sinusoidal variations in visual feedback delay between 0 and 400 msec were imposed during a tracking task at frequencies between .05 and 2 Hz. The results show that RMS error, gain (fundamental FFT peak for the cursor signal/fundamental FFT peak for the target signal), and phase (phase angle difference between the target signal and the cursor signal) of the tracking control system are independent of variable feedback delay imposed across a forty-fold range of frequencies. One important implication of these findings is that operators may have limited ability to adapt to feedback delay conditions that may be present during teleoperation of large mobile mining equipment.
Training Perceptual-Rule Based Skills
Authors: Walker Neff , Fisk Arthur D. , Phipps Donita , Kirlik Alex
Published: January 2012

The results of an experiment are discussed that address how best to train perceptual-rule based skills within a domain where rules correlate to perceptual aspects of a dynamic evolving environment. Participants performed the role of football quarterback where the object of the task was to learn to identify the correct pass receiver in a simulated football system. The correct receiver could always be specified by a set of rules or subtle perceptual cues. Subjects were assigned to one of four training groups which were constructed by complete crossing of rule versus no rule learning and visual enhancement training versus no visual enhancement training. After training trials all subjects transferred to new plays in which new rules or perceptual cues were required. Transfer performance was superior for the participants who received the visually enhanced training. These results are discussed in light of theories of part-task training.
Toward Optimizing the Impact of Developmental Feedback in Team Training Simulations
Authors: Smith Kimberly A.
Published: January 2012

This paper reports evaluation data from an effort to train assertive communication in aircrews. The impact of preliminary conceptual training and simulator instructions which focused trainees on the target skill was examined on the reported usefulness of post-simulation feedback. Results indicated that trainees who received conceptual training one week prior to a simulation exercise reported the feedback they received on their performance more useful than those who had not received preliminary training. Further, trainees who were informed ahead of time which skill dimension was the focus of the simulation rated the feedback they received on their performance less useful than those who were not given this information. Implications for the use of simulation to enhance teamwork skills and attitudes are discussed.
Trade-Offs in a Team Tracking Task as a Function of Performance Feedback
Authors: Jentsch Florian G. , Navarro Guillermo , Bowers Clint A.
Published: January 2012

Team members often have to make decisions about which aspects of their tasks they should emphasize. One of the factors that may determine these decisions is the type of feedback. In this study, the influence of the type of concurrent performance feedback on team performance in a pursuit tracking task was investigated. Eighteen dyads performed a reciprocally interdependent team tracking task. Subjects' goal was to optimize team performance under three different conditions: One team member never received feedback, while the other received either team, individual, or no feedback. The tracking error was measured. The results from this study largely confirmed the findings from previous research which had indicated a feedback by team member interaction: When provided with individual feedback, team members seemed to emphasize the perceived individual aspects of their task at the expense of the team effort. Under team feedback, the reverse occurred. In support of these findings, the current study found a significant gap in performance between the two team members under individual feedback conditions. The team member receiving individual feedback performed significantly better than their interdependent cohort. Yet, when subjects received either team or no feedback, their performance was worse than that of their team member, even if the difference failed to reach statistical significance. The results suggest that feedback can adequately focus subjects' attention towards specific aspects of their task.
The Effects of Back Angle on Target Detection
Authors: Edwards R J , Streets D F , Bond G
Published: January 2012

It is suggested that crew members of future armoured vehicles will be reclined. However, information relating to task performance when reclined for prolonged (i.e. >30 minutes) periods is limited. This study has investigated the effects of prolonged reclining on a simple target detection task.

Twelve subjects undertook four separate seventy minute studies in the upright (control) seated posture or reclined, with head support, at 25°, 45°, and 65° from the vertical. Subjects viewed a model scrubland scene, with light emitting diodes hidden behind the scrub, through seven vision blocks which covered a 300° field of view. During the first 10 minutes subjects responded to a sequence of 32 randomly distributed signals of 4 seconds length, with 15 seconds between each signal. They rested for 50 minutes before repeating the 10 minute test epoch. Measurements taken were number of responses, body part discomfort, sleepiness and Stress and Arousal Checklist, and were analysed using Analysis of Variance.

Percentage targets detected significantly reduced with back angle, with the greatest reduction being in the subjects' frontal arc. General body and neck discomfort and sleepiness significantly increased with back angle. Reported stress significantly increased and arousal decreased, but only between 0° and 65°. There was no significant time effect.

Possible explanations for the results are that the chair and posture inhibited freedom and ease of movement, or that increased discomfort at the more acute angles may have resulted in an altered searching behaviour. Whatever the mechanism this study has shown that reclined postures may significantly impair the performance of an all-round surveillance task, particularly at the more acute back angles.
The Basis for the Perception and Control of Altitude: Splay & Depression Angle Components of Optical Flow
Authors: Garness Sheila A. , Flach John M. , Stanard Terry , Warren Rik
Published: January 2012

This study evaluated subjects ability to track a constant altitude as a function of the structure in the optical flow field. Optic flow was manipulated by using four different types of ground texture (splay angle, depression angle, random dot, and block textures) crossed with two global optical flow (GOF) rates (0 and 3 eyeheights/s). The subjects were asked to maintain a constant altitude while wind disturbances randomly perturbed them on vertical, lateral, and fore-aft axes. The critical independent variables were texture type and GOF rate. Texture type was a within-subjects variable while GOF rate was a between-subjects variable. The main dependent variables included RMS height error and the correlation between subjects stick activity and the three wind disturbances. For both dependent variables, an interaction was found in that the depression angle texture provided superior performance in a hover or 0 GOF rate condition. The splay angle texture provided a constant level of performance for both GOF rates, being superior to depression angle in the higher GOF rate. These results are consistent with Flach et al.'s (1992) hypothesis that the ability to pick-up altitude information from the optic flow field depends upon the amount of optical activity that is specific to changes in altitude (signal) rather than specific to changes in lateral or fore-aft position (noise). This hypothesis provides a higher order explanation for previous results on the control of altitude which had been thought to be inconsistent.
Navigation Display Integration in the General Aviation Environment: Performance using the Horizontal Situation Indicator
Authors: Beringer Dennis B. , Harris Howard C.
Published: January 2012

Much effort has been invested in examining integrated instrumentation for advanced aircraft cockpits, but little comparable effort has been directed toward the greatest number of aircraft presently flying - those in the general aviation environment. This study examined the benefits of a simple and widely available integrated instrument, the horizontal situation indicator (HSI), in the performance of simple navigation and orientation tasks by private pilots. Tested in the context of the multiple-processor Basic General Aviation Research Simulator (BGARS), pilots exhibited significantly fewer navigational reversals and orientational errors when using the HSI (in comparison with their performances when using the traditional VOR and Directional Gyro combination). These results were consistent with but even more definitive than an earlier sample of instructor pilots. Similar benefits in procedural error reduction were also found when instrument index markers, or “bugs,” were used as short-term memory aids.
Releasing the Hook on the Copilot's Catch 22
Authors: Besco Robert O.
Published: January 2012

The P.A.C.E. operational methodology presented here is designed to assist subordinate crew members in resolving the basic question of the junior airman: “To Intervene or Not to Intervene?.” The P.A.C.E. system has unraveled “The Copilot's Catch 22: You are damned if you ignore the Captain's mistakes; you are damned if you do something about them.”

The four operational procedure steps of P.A.C.E. establish a systematic intervention progression of inquiries to reduce risks at each level of the sequence. The P.A.C.E. skills enable subordinate flight crew members to use proven operationally based procedures to effectively intervene when a Captain is not performing up to reasonable professional standards.

P.A.C.E. procedures have been developed from case studies of voice recorder transcripts of National Transportation Safety Board aircraft accident reports. The P.A.C.E. methodology provides the skill and knowledge to implement new, operationally relevant components into Crew Resource Management training for each individual organization.
General Aviation Airplane Accidents Involving Spatial Disorientation
Authors: Mortimer Rudolf G.
Published: January 2012

National Transportation Safety Board accident data for 1983-1991 were used to compare those general aviation accident cases that involved spatial disorientation (SD) with all others. About 2.1% of general aviation airplane accidents involved SD. Those accidents were associated with low ceilings, restricted visibility, precipitation, darkness and instrument flight conditions. Pilots in certain professions, particularly those in business, were more involved in SD accidents. Pilots in SD accidents were more often under pressure, fatigue, anxiety, physical impairment and alcohol or drugs. The pilots' total and night flying experience were inversely related to involvement in SD accidents. Spatial disorientation accidents accounted for a small number of crashes, but they were very severe-fatalities occurred in 92%, they accounted for 9.9% of the fatal accidents, 11% of the fatalities and in 95% the aircraft were destroyed. The results suggest that the pilots in SD accidents lacked the flight experience necessary to recognize or cope with the stimuli that induce SD, which was compounded by fatigue, alcohol/drugs or pressure and other psychological and physical impairments. Specific exposure to conditions leading to SD in training of general aviation and all pilots should be evaluated to help them to recognize it, and the techniques used by experienced pilots to combat its onset and effects should be studied and used in training. Improved human factors engineering of the cockpit instrumentation is also needed.
Human Factors in Aviation Maintenance and Inspection: Research Responding to Safety Demands of Industry
Authors: Shepherd William T. , Johnson William B.
Published: January 2012

For over five years the Federal Aviation Administration has conducted extensive research and development to enhance human performance and safety in aircraft maintenance and inspection. Directed by the Office of Aviation Medicine(AAM) the program has engaged in pragmatic research capitalizing on basic scientific principles and a thorough working relationship with all levels of aviation maintenance practitioners. This paper describes a few of the example research products that are currently promoting safety and efficiency in maintenance applications worldwide.
Electronic Human Factors Guide for Aviation Maintenance
Authors: Jones Julie A. , Widjaja T. Kiki
Published: January 2012

Technological advances in the area of computer software, hardware and peripherals have made digital information technology feasible. The Federal Aviation Administration Office of Aviation Medicine has been investigating the application of such technology. The overall goal is to increase accessibility and to improve distribution of Human Factors research reports and information to the aviation maintenance industry. The latest digital documentation project is the Electronic Human Factors Guide for Aviation Maintenance (E-Guide). The E-Guide is a hypermedia version of the Human Factors Guide for Aviation Maintenance (the Guide) which is described elsewhere in this symposium. This paper describes the design goals, key features, and future plans for the E-Guide.
The Prediction of Pilot Subjective Workload Ratings
Authors: Aretz Anthony J. , Shacklett Scott F. , Acquaro Phil L. , Miller Derek
Published: January 2012

This paper investigated potential variables that predict pilot subjective workload ratings. A correlational design was used to regress NASA TLX subjective workload ratings onto four independent variables (the number of concurrent tasks, task type, task combination, and flight experience). A pilot selection simulator was used to present five different flight tasks, in different combinations, to 15 cadets at the USAF Academy. The results indicated the number of concurrent tasks had the largest impact on subjective workload ratings, followed by subjects' flight experience. The data also showed that the effort dimension of the NASA TLX contributed the most variance to the overall weighted workload ratings. The implication for theoreticians and designers is that the number of concurrent tasks, experience, and perceived effort seem to be key contributor to subjective workload ratings.
Free Flight: Human Factors Implications
Authors: Garland Daniel J. , Abbott David W. , Hopkin V. David , Wise John A. , Benel Russell A. , Smith Phillip J.
Published: January 2012

There is a real possibility that the air traffic control system in the United States will change radically in the next decade. One vision–“free flight” or “free routing”–is to move most of the responsibility for navigation and separation back to the cockpit and away from ground based air traffic systems. The basic notion of free flight is that each flight would be completely determined by the user, i.e. by some form of airline/pilot combination, and would not need to follow pre-defined airways or altitudes. The airlines would inform the air traffic system of each aircraft's intentions, but would not have to seek any prior air traffic approval. The job of the air traffic system would be to meet the user's requirements, but not to suggest what those requirements should be. However, the air traffic system would be expected to collaborate with the airlines to ensure the safe passage of flights and to intervene when aircraft separation requirements are jeopardized or violated. Such a system would bring with it dramatic changes in the roles of all the human members of the aviation system, and as such, would have significant human factors impacts. The goal of this panel will be to identify and discuss some of those issues.
Visual Search and the Older Adult: Not all is Lost
Authors: Humphrey Darryl G. , Kramer Arthur F. , Schneider Donnelle R.
Published: January 2012

Plude and Doussard-Roosevelt (1989) reported age-related search slope differences in a conjunction search task but not in a feature search task. According to Feature Integration Theory (Treisman & Gelade, 1980), older adults may suffer an impairment in the feature integration mechanism required for conjunction searches. We extend this work by examining age-related differences a series of feature, conjunction, and triple conjunction search tasks. The results of the feature and conjunction search tasks support the previous findings. However, the results of the triple conjunction search task suggest that the conjunction search impairment is not universal. As the triple conjunction search results are difficult to accommodate within Feature Integration Theory, the results are discussed within the framework of the Guided Search model of visual selective attention.
Design Locally: Validate Globally
Authors: Elkins Erich , Quinn John E.
Published: January 2012

A process for developing the user interface and the industrial design for products intended for international markets is presented. The process was derived from lessons learned while developing a business telecommunications device. The device required an interface that was easier to use and a product design that would be attractive to worldwide business users. The design process was based on two iterations of user testing. The first iteration included 51 users from three major U.S. metropolitan areas; while the second had 294 users from four European cities, three U.S., and two Asian. The recommended process requires that multiple competing designs be presented to users for iterative validation and revision before selecting the final design. The competing designs increase the likelihood that cultural differences are met and the best design solution is achieved.
Customers with Disabilities: The Ultimate Usability Challenge
Authors: Tobias Jim , Benoit Marilyn , Francik Ellen , Palmer Susan
Published: January 2012

This panel will discuss both technical and organizational issues regarding guaranteeing that new telecommunications services are as accessible as possible to customers with disabilities. The panelists represent several large telecommunications companies and come from a variety of backgrounds and corporate organizations. Emphasis will be placed on the importance of universal design rather than creating specialized products.
Expert Reviews: How Many Experts is Enough?
Authors: Dumas Joseph , Sorce James , Virzi Robert
Published: January 2012

We asked five usability specialists to review the user interface to a phone-based, interactive voice response system. The experts were instructed to conduct their review independently in three one-hour sessions and to record each usability problem on a Problem Description Sheet along with the elapsed time from the beginning of the hour. Each expert then spent one hour reviewing their problem sheets and making a summary list of problems. Finally, the experts spent two hours together on a conference call discussing their impressions and coming to consensus on a prioritized list of problems and solutions. The results showed that when allocating expert time, it is more effective to have a greater number of experts spend fewer hours than to use fewer experts for more hours. The individual summaries included the majority of the severe problems, but left out many less severe problems and added new problems. The group report did not surface any new problems, but described the problems as being caused by more basic design flaws and proposed solutions that focused on the conceptual model on which the design was based.
Single Line Display Menu
Authors: Han Sung H. , Kwahk Jiyoung
Published: January 2012

Many electronic consumer products use a single line display which is capable of presenting a limited number of characters at a time. Although many design guidelines have been proposed, they are applicable only to the menus on ordinary CRT displays. This study examined the effects of four different variables: menu structure, user experience, navigation aid, and number of target items on designing the menu on a single line display. Four dependent measures, speed, accuracy, efficiency, and user preference of a target search task, were collected. The results showed that the 82 structure turned out to be an optimal menu structure for single-line display menus. The navigation aid improved the search performance of the inexperienced. Interestingly, multiple target search tasks recorded a better performance than single target search tasks. Based on the results, design implications were discussed.
Adult Notions of Adults' and Children's Perceptions of Consumer Product Risk
Authors: Hammond Amy J.
Published: January 2012

An experiment was performed to examine adults' perceptions of other adults' and children's perceptions of risk. The differences in how adults assess risk to themselves, to other adults, and to children based on their own perceptions and on the perceptions they believe the “others” will hold for themselves were explored. Results found that adult subjects do judge risk as greater for others than for themselves, particularly for young children. A “superiority bias” was found, such that products were assessed to be more risky for others than others would assess for themselves. Implications of a discrepancy between the perceptions adults assign to children and the perceptions of children themselves is discussed.
Participatory Design Shapes Future of Telephone Handsets
Authors: Dolan William R. , Wiklund Michael E. , Logan Robert J. , Augaitis Sheila
Published: January 2012

Telephone handset design has evolved for decades along with advancements in technology and manufacturing methods. Today, a handset could be reduced to a slim rod incorporating a miniaturized earpiece and microphone. However, most handsets look like the venerable K-type handset, such as those found today on many household and business telephones. Should future handsets continue to follow suit, or are there significant opportunities for improvement? Initially, we conducted five focus groups to answer this question. To begin each session, we photographed consumers holding handsets to assess gripping styles. Then, consumers rank ordered six conventionally designed handsets and six progressively designed handsets according to several ergonomic and emotional attributes. They also critiqued the handset designs according to personal preference and built clay models of their ideal handset. Based on this input, our team of human factors and industrial design specialists designed 6 new concepts, then obtained quantitative and qualitative feedback by conducting thirty focus groups in three metropolitan areas. This follow-on research, that included free association, sample handset assessment and, paired comparison and ranking exercises, identified significant opportunities to improve handset comfort, appearance, and emotional appeal. A Kruskall-Wallace H-test showed few significant differences in consumer preferences among 18 sample handsets. Our results indicate that users prefer a handset that can be shouldered, looks modern, feels good in the hand, and conforms to the face. We found that users are receptive to design innovation, but only if there is an ergonomic payoff. We include a discussion of detailed design recommendations in the last two sections.
Preparing for the Human Factors/Ergonomics Job Market
Authors: Shapiro Ronald G. , Brown Megan L. , Fogleman Maxwell , Goldberg Joseph H. , Granda Richard E. , Hale Joseph P. , Sanders Elizabeth B.-N.
Published: January 2012

The panel is designed to help an individual decide on a specialization in human factors/ergonomics and to prepare to enter the human factors job market. Panelists were selected to represent a cross-section of the field, and are from the following sectors: the electronics industry (Megan Brown), loss prevention research (Max Fogleman), academia (Joe Goldberg), the computer industry (Dick Granda), the government (Joe Hale), and consulting (Liz Sanders).
An Estimation of Lumbar Height and Depth for the Design of Seating
Authors: Dowell William R.
Published: January 2012

The horizontal and vertical position of the apex of the lumbar curve of 773 seated persons were measured. The position of the lumbar landmark is given. Three common seated anthropometric measurements were also taken: popliteal height, buttock-popliteal length, and elbow rest height. The three common measurements are compared with data from an existing anthropometric data base.
Concepts for Designing a Building
Authors: McCrobie Daniel
Published: January 2012

This panel was designed by Marie Robinson of Pacific Bell, the Program Chair for the Environmental Design Technical Group. Marie wanted to put together several speakers who have unique views and different backgrounds on how buildings should be designed for the user. The resulting panel should be an interesting mix of ideas, all with a focus on the user.
Signal Words: Perceived Carefulness by the Developmentally Disabled
Authors: Silver N. Clayton , Tubilleja Kenneth , Ferrante Rozana
Published: January 2012

The current standards recommend using signal words such as DANGER, WARNING, and CAUTION to connote varying degrees of hazard. Most research concerning the connoted strength of signal words has used college students as participants. One at-risk population that has not been adequately studied, however, includes people with developmental disabilities. The purpose of the present research was to determine whether people with developmental disabilities understand these signal words. Moreover, connotation comparisons would be made concerning other populations sampled from previous research. A sample of 46 people with developmental disabilities rated 43 potential signal words on how careful they would be after seeing each term. In general, the ratings of the developmentally disabled were consistent with populations sampled from previous research. The words that were frequently left blank by the developmentally disabled were used less frequently in the English language and were higher in grade level. The forensic implications and relevance concerning hazard communication are discussed.
State of the Art and Current Activities in Human Modelling Technology
Authors: Nayar Narinder
Published: January 2012

Computer-based human modelling technology has been in existence since the early 1980s. However, most earlier human models were either hard to use or lacked appealing graphics. With rapid developments in 3D computer graphics, it is now possible to interactively manipulate and analyze human models in a virtual environment. This coupled with growing user interest has spurred rapid development and use of human modelling and simulation.
Ergonomic Glove: Design and Evaluation
Authors: Muralidhar A. , Bishu R. R. , Hallbeck M. S
Published: January 2012

A new design for gloves was developed based on the principle of selective protection, where protective material is introduced in varying levels over different parts of the glove, in order to provide protection where it is most needed, and at the same time preserve the desirable dexterity and strength capabilities of the barehand, optimizing the trade-off between protection and performance. The pattern for selective protection was arrived at based on existing research, and two pairs of gloves incorporating different levels of protection have been prototyped and are currently being tested using a battery of performance tests and an Algometer test for pressure sensitivity. A battery of tests was developed to evaluate a new glove design which used the principle of selective levels of protection over different parts of the hand, in order to maximize protection, and minimize loss of dexterity. The test battery comprised of four dexterity tasks and a maximal voluntary grip strength task. The battery assessed the performance of 5 hand conditions, barehand, single glove (one layer), double glove (two layers), and two prototype gloves, one with one layer of protection (contour glove) and the other with four layers of protection over selected parts of the hand (laminar glove). The evaluation compared the performance of the prototype gloves developed with respect to the performance with the double layer glove and the single layer glove. The results indicated that the performance of the prototype gloves was comparable, and that the performance times for the double glove and the two prototype gloves tested were not significantly different. For the test of grip strength, the two prototype gloves tested enabled better performance than the double glove. The assembly task performance for the prototype II (laminar glove) was significantly lower than that of the other glove types tested
Activity of Index Finger Muscles during Typing
Authors: Sommerich Carolyn M. , Marras William S. , Parnianpour Mohamad
Published: January 2012

An electromyographic investigation was conducted of finger and wrist muscle activity during typing. Examination of the data revealed substantial activity of the extrinsic extensor, a muscle which is ignored in many existing biomechanical finger models. This paper describes activity of the extensor muscle during typing, in absolute terms and relative to activity of the extrinsic flexors. Amplitude probability distribution analyses demonstrated that static extensor activity exceeded 5% MVC for all subjects. Two subjects exhibited pronounced patterns of coactivity in the extrinsic extensor and flexor muscles. Biomechanical modeling efforts demonstrated similar force contributions from the extrinsic extensors and flexors. Based on these results, neglect of finger extensor activity would result in underestimation of finger joint loading.
Maximum Acceptable Load for Lifting and Carrying in Two-Person Teams
Authors: Sharp Marilyn A. , Rice Valerie J. , Nindl Bradley C. , Mello Robert P.
Published: January 2012

The purpose of this study was to determine and verify the maximum acceptable load for lifting and carrying (MALL&C) in single- and mixed-gender two-person teams. Participants lifted and carried a box 7.2 meters and placed it on a 132 cm high shelf, at rates of 1 x/min and 4 x/min. All male teams lifted and carried significantly (p<.05) more weight than all female teams or mixed-gender teams, and mixed-gender teams carried more than all female teams (p>.05). Our findings demonstrate that 1) individuals working alone or in teams can accurately estimate their ability to lift and carry loads for an hour, and that 2) when working in pairs, team MAL-L&C are approximately equal to the sum of their individual MAL-L&C. Percentile norms for MAL-L&Cs are provided for male, female, and mixed gender teams.
The Effects of Lifting Frequency on the Dynamics of Lifting
Authors: Mirka Gary A. , Kelaher Daniel P.
Published: January 2012

The goal of this study was to quantify the effects of different lifting frequencies (3, 6 and 9 lifts/minute) at different lifting heights (30 and 60 cm) on the kinematics of the lumbar region. Each of these lifting tasks was performed for twenty minutes. The time dependent traces of the both the mean and standard deviation of sagittal acceleration showed subject dependent trends over time. Averaged across time, the results of this study reveal that there is a non-linear increase in the sagittal acceleration with greater frequency of lifting.