bluuebunny/crossref_metadata_2025 huggingface dataset:
Verbalizable Knowledge of Skilled Task Performance
Authors: Sanderson Penelope M. , Vicente Kim J.
Published: January 2012

It has recently been shown that variables which affect skilled performance of a task can have no effect on subjects' ability to answer questions about the task and that variables which affect question answering can have no effect on skilled performance. When seen in the same task, this is termed a ‘dissociation’. However, for those concerned with the elicitation of knowledge for engineering purposes, these results are disturbing. The present paper argues that judgments of dissociation may be premature if important parts of an expert's knowledge are not being probed. A series of experiments using a simulated city transport task shows that overall performance on more detailed questionnaires generally does not improve with practice on the transport task. However, there is noticeable improvement on some individual auestions. The reasons for this are discussed.
Measurement of Pressure Distributions as a Function of Seating Parameters
Authors: Treaster Delia
Published: January 2012

This study examines the effect of seat pan and backrest angles on the distribution of seating pressures. Experimental equipment and data analysis which allow continuous measurement, quantification and analysis of seating pressures on the seat pan and backrest are described. It was found that the seat and backrest angles affected the distribution of pressure on both the seat pan and backrest. The results indicate that increasing the backrest angle was more effective in relieving areas of high pressure than increasing the seat pan angle.
An Electromyographic Investigation of Neck Angles for Microscopists
Authors: Lee K.S. , Waikar A.M. , Aghazadeh F. , Tandon S.
Published: January 2012

This study investigated the musculoskeletal stress experienced by microscopists for different neck angles. Electromyography was employed for objective evaluation of the musculoskeletal stress which was compared with the subjective assessmnent obtained through questionnaire. Subjects viewed through the microscopes for two hours at a time in a constrained posture with neck angles of 25, 45 and 65 degrees. Electromyograms (EMG) were recorded for the cervical, trapezius, lattisimus dorsi and erector spinae regions. Subjects also reported the perceived level of stress every fifteen minutes. Both objective and subjective criteria revealed significant increases in the levels of musculoskeletal stress over time of the experiment for all levels of neck angles, in most muscles tested. Higher levels of stress were observed for erector spinae and cervical regions for 65 and 45 degree neck angles. It was concluded that the stress may be reduced by utilizing optimal neck angle in designing the microscope workplace layout.
Selected Technology Thrusts Supporting Emerging Training Systems: Computer-Based Authoring, Artificial Intelligence, and Embedded Training
Authors: Kincaid J. Peter
Published: January 2012

This symposium is a follow-up to a sumposium held at last year's HFS meeting. “Training Technology in the 1990s: Development, Application and Research Issues.” Representatives from the three military services discussed how many facets of training technology would affect current and future design applications and research issues relevant to military training systems. Two topics from that session (artificial intelligence and embedded training) and one other topic (computer-based authoring of technical information) have beer selected for in-depth discussion. Each technology is computer-based and has been exploited to only a limited degree.

The object of this symposium is to provide a focus for describing how the three technologies are important for emerging and future training systems. For example, nearly all technical information (TI) for maintaining and operating weapon systems in the field is currently paper-based but the Department of Defense is committed to transitioning to electronic delivery of TI within the next decade. Many R&D issues must be resolved in the interim. Similarly, the technologies of embedded training and artificial intelligence have considerable potential for future training systems once a number of R&D issues are successfully addressed.

All three services have on-going research and development programs for the technologies covered in this sumposium. Each topic is presented by representatives from at least two military behavioral laboratories: for computer-based authoring, Naval Training Systems Center (NTSC), Naval Personnel Research and Development Center (NPRDC) and Army Research Institute (ARI); for artificial intelligence, Air Force Human Resources Laboratory (AFHRL) and NTSC; and for embedded training, NTSC and ARI. The goals of the symposium are: (1) to make clearer the most pressing R&D issues associated with these technologies, and (2) to discuss how future training systems might incorporate them.
The Effects of Foveal Load on Peripheral Visual Sensitivity
Authors: Rinalducci Edward J. , Rose Paul N.
Published: January 2012

The main objective of the research was to investigate the effects of load on peripheral sensitivity in the visual field. Foveal load was varied by using simple fixation of a vs. a first-order (rate) compensatory tracking task. Peripheral sensitivity was determined simultaneously for light flashes located at different eccentricities along the horizontal meridian. The effects of training on the tracking task were also examined. In general, the results showed no losses in peripheral sensitivity under the experimental conditions employed, contrary to data from previous studies.
Most Similar is Different: Response Bias in Lineups
Authors: Wogalter Michael S. , Jensen Dean G.
Published: January 2012

Previous research has shown that distractor faces made up of features of previously seen target faces are more likely to be selected as targets than the targets themselves. The present experiments sought to determine whether there is a tendency to pick a face out of a lineup if the face is more similar to the other lineup members than they are to each other. In Experiment 1, 25 subjects ranked members of lineups on similarity to target faces. The important comparisons were between rankings of the faces similar to the distractors (the critical faces), target faces, and other distractors. When the target faces were present in the lineup, no significant difference between rankings of the targets and the critical faces was found. When no targets were present in the lineup the critical faces were judged to be more like the targets than were the other distractors. This latter finding was replicated in Experiment 2 using visual stimuli other than faces. Implications for choosing police lineups are discussed.
Expert Systems in a Social Environment—Human Factors Concerns
Authors: Ostberg Olov
Published: January 2012

There is an abundance of promises for Expert Systems with user-friendly and intelligent interfaces providing cloned expertise for augmented job performance. A closer look reveals that very few systems are in operation, and that there is a serious gap between claims and reality. Basically, “Knowledge Engineering” is a modern form of “Work Study Engineering”, and yet job and organizational design issues are rarely addressed in the literature on designing Expert Systems. This serious gap is discussed.
Low Vision Aids
Authors: Rosenthal Bruce P.
Published: January 2012

Visual impairment is increasing as a major disability in our aging population. Recent medical and surgical advances in diagnosis and treatment are adding to the increasing numbers of partially sighted persons. Rehabilitation with low vision aids will therefore assume an important role in keeping the “older” individual active, alert, and independent.
Experimental Evaluation of a Mnemonic Command Syntax for Controlling Advanced Telecommunications Services
Authors: Root Robert W. , Koster Christopher R.
Published: January 2012

We conducted an experimental evaluation of a mnemonic keypad interface for controlling telecommunications services. Users of the new interface remembered more services and commands than users of the standard interface. However, users did not change their patterns of service use as a result of the new interface. We conclude that the impact of interface design on service use depends partly on the characteristics of users and partly on the characteristics of services.
The use of and and or in a natural language computer interface
Authors: Ogden William , Kaplan Craig
Published: January 2012

A study of the use of and and or for specifying intersection and union relationships between conjoined qualifiers of varying characteristics was conducted using a simulated natural language query system. Subjects always used or correctly to indicate union but and was used to indicate both union and intersection. Interpretation rules were defined that could be used to clarify the intended meaning for and for some but not all of the cases. The results indicated subjects could implicitly learn to be more precise. These results suggest that natural language interfaces can be built to recognize ambiguous input and should prompt users for clarification. Simple syntactic elements that would distinguish the meaning of and can be defined and taught to users.
Operator/Manager Classification as a Precursor to Function Allocation
Authors: Roberts David P. , Gawron Valerie J.
Published: January 2012

As part of the Cockpit Automation Technology program, a procedure was developed to classify functions into operator or manager roles. The functions were derived from sample air-to-air and air-to-ground tactical missions. Each function in these missions was classified as either operator or manager roles based on the action required by the function. This procedure provided guidelines for subsequent allocation of the function to a crew member or to a machine, depending on if a man or a machine is to be in the cockpit.
Planning for Unanticipated Satellite Servicing Teleoperations
Authors: Rice John R. , Yorchak John P. , Hartley Craig S.
Published: January 2012

The role that man will play in the space-based servicing of satellites will change with standardization and automation of such operations. This change will permit man to dedicate more of his time in space to tasks that require his unique intellectual, manipulative, and perceptual abilities. However, if history is any indication, man cannot be completely removed from servicing duties because unanticipated servicing operations occasionally will require his direct intervention and control through either extra-vehicular activities (EVA) or teleoperations. As a result, certain minimum user-system interface capabilites must be maintained, no matter how sophisticated future technology becomes. This paper discusses research related to some of the basic human factors problems that will probably always have an impact on space-based teleoperated servicing operations. The implicit warning is that future advanced systems must implement solutions to these problems if humans are to provide effective backup support. Furthermore, the authors believe that there are several critical gaps in our present knowledge of teleoperator human factors that must be closed before such backup operations can be effective. There is a danger that system developers may become so enamored of advanced teleoperator technology that they may fail to provide an adequate user/system interface for backup operations. Human factors issues discussed include: vision systems, control devices and communication time delays. Each issues section concludes with a list of suggested research topics that address gaps in our present knowledge about teleoperator human factors.
Capture of Satellites having Rotational Motion
Authors: Hartley Craig S. , Cwynar David J. , Garcia Kathy D. , Schein Robert A.
Published: January 2012

This paper describes the results of system development simulations conducted to resolve key human factors issues involved in the capture of satellites having rotational motion, using both manned and remotely piloted vehicles. These man-in-the-loop simulations of remotely piloted Orbital Maneuvering Vehicle (OMV) spacecraft, combined with recent on-orbit experience from Manned Maneuvering Unit (MMU) capture and retrieval missions, have provided results related to many of the human factors issues inherent in such piloting tasks. The results discussed relate to control authority, piloting techniques, communications time delays, plume impingement, contact dynamics, controls, and displays. The paper concludes with a summary table of knowledge established through simulations and mission experience that is applicable to capture and retrieval of dynamic satellites.
Subjective Preference and use of Workstation Adjustability Features
Authors: Hozeski Kenneth W.
Published: January 2012

In 18 separate 2-hour sessions, 22 female subjects performed a word processing task while seated on 6 different chairs in front of VDT's that were placed on 3 different worksurfaces. The chair types included posturetilt, swivel-tilt, synchro-tilt, and static with adjustability. The worlsurfaces consisted of a multilevel fixed surface, a fixed surface with adjustable accessories for a keyboard and display, and a fully adjustable worksurface. In addition to the word processing task, the subjects preferentially ranked both chairs and worksurfaces and rated each chair for comfort attributes on various body parts. The data base was subjected to an analysis of variance with the sources being chair, worksurface, and the possible interaction of these products, the results showed significant f-ratios for chairs. A similar finding was also observed for the work-surfaces. An examination of the net words per minute data found that a preferred chair and/or worksurface was identifiable. Analysis of a body-parts comfort scale did not differentiate significantly between the chairs or worksurfaces.
A Method of Developing more Realistic Predictive Models
Authors: Imrhan Sheik N.
Published: January 2012

This study demonstrates a better method of regression analysis than Ordinary Least Squares (OLS) method under certain conditions. Ridge Regression, as it is called is useful in situations where there are strong intercorrelations among regressor variables – a condition called multicollinearity. When OLS regression is used to model the relationship between the response variable and the regressor variables the model may exhibit some undesirable properties. Using ergonomics data exhibiting multicollinearity the use of the Ridge technique is demonstrated. An OLS model for the same data is also presented and compared with the Ridge models. The Ridge model was superior to the latter. It exhibited more realistic properties and predicted more accurately. It is therefore proposed as a valuable tool to the Human Factors/Ergonomics researcher in the development of regression models with highly intercorrelated regressor variables.
Human Strength as a Predictor of Lifting Capacity
Authors: Ayoub M.M. , Selan J.L. , Chen H.C.
Published: January 2012

A sampling of lifting capacity prediction models utilizing human strength measurements as input are presented. The models utilize isometric, isokinetic, and/or isoinertial strength measurements. Comparison of such predictive models appears to indicate that lifting capacity is better predicted using dynamic rather than static strength tests.
Scenario Analysis of Petrochemical Worker Injuries
Authors: Schmidt John K.
Published: January 2012

More traditional approaches to accident reporting and analysis have received much critisism in recent years. The dispute apparently lies in their inability to facilitate intervention development due to a primary non-ergonomic orientation as well as limited suitability as an information management system. Laughery, Petree, Schmidt, Schwartz, Walsh and Imig (1983) in an effort to address these issues adopted the human factors based scenario and analytic technique developed by Drury and Brill (1983) and devised a accident coding and analysis system. In an study of 1,694 operator cases taken over a three year period at a petrochemical facility in the Houston, TX area, five separate accident patterns accounting for 80% of all the reported cases were found. The scenarios are as follows:

1) muscular/skeletal strain in system operation. 2) chemical release due to system breakdown. 3) obstruction in the workspace. 4) unsolicited interface movement during system operation. 5) poor footing in the workspace.

A closer analysis of each scenario revealed apparent design flaws and managerial policy problems, that if corrected would reduce incident numbers significantly.
Performance of Three Visual Approach Landing Light Systems
Authors: Kellogg Robert S. , Hubbard David C.
Published: January 2012

This report documents the methodology and experimental approach taken to evaluate the effectiveness of the three visual approach landing light systems: Visual Approach Slope Indicator (VASI), Precision Approach Path Indicator (PAPI), and Pulse Light Approach Slope Indicator (PLASI). Performance measures were taken inflight in the Air Force T-37 jet trainer, which produced objective determinations of deviations from glideslope on final approach, for each system. The subjects were experienced Air Force Instructor Pilots. Results showed that PAPI and PLASI were statistically equivalent, but that both were superior to VASI. Some subjective pilot evaluations of the three systems are also described.
On the Semiology of Object, Space and Behavior: The Design of Strategic Design Languages
Authors: Rheinfrank John J. , Evenson Shelley K. , Kresge Keith J. , Sanders Elizabeth B.-N.
Published: January 2012

This paper addresses an approach now being used to develop solutions to complex architectural, product, graphic and information design problems. Central to the approach is the integration of projected objectives and strategic design principles. One finding is that teams can achieve this integration most directly and powerfully by generating design languages. The paper further addresses the conceptual framework from which we developed the idea of design languages and an expanding set of problem-solving tools which we uncovered in the process of evolving the work.
Toward a Theory of Information Design
Authors: Sanders Elizabeth B.-N.
Published: January 2012

This paper offers an exploration of a theory of information design in which information design and graphic (visual) design are viewed as related and parallel processes within the larger process of communication design. Information design is seen as the means for designing within the temporal domain, a domain in which ideas are expressed over time, rather than holistically. This domain includes, but is not limited to, the written word. Information design is, therefore, seen as essential in the design of complex systems involving complex information. An explanation of information design, the assumptions inherent in it, its role within communication design and its uses are explored.
Human Factors Guidelines and Methodology in the Design of a User Computer Interface: A Case Study
Authors: Richards Robert E. , Gilmore Walter E. , Haney Lon N.
Published: January 2012

In this case study, human factors personnel were requested to participate in a project team of programmers and operations specialists to design a cathode ray tube (CRT) display system for a complex process control application. This presentation describes the process and benefits obtained by incorporating human factors guidelines and methods in system design. Standard human engineering guidelines and techniques were utilized by the project team. In addition, previously published documents and research findings sponsored by the United States Nuclear Regulatory Commission (USNRC) were used. Preliminary tasks involved a review of the draft plant procedures. Then, interviews with operators were conducted to establish the initial information for the displays. These initial requirements were evaluated against existing guidelines and criteria to determine the optimal presentation formats. Detailed steps of the approaches used, design decisions made, and tradeoffs that resulted in the final user acceptable design are discussed.
Evaluating Employee Participation Programs Addressing Health, Safety, and Ergonomic Issues in the United States
Authors: Robertson Michelle M. , Bowman Joseph D. , Rosenberg Steve M.
Published: January 2012

With the increase of system complexity, organizations are having to respond to these new demands by utilizing employee involvement methods. This paper attempts to review and examine representative studies of employee participation with particular focus on health, safety and ergonomic issues. Four topics are presented in this paper (1) the different organizational forms of participatory approaches (2) goals of the employee participation programs (3) evaluations criteria of the program and (4) conclusions. It appears that worker participatory programs are successful in addressing health, safety and ergonomie issues. However, in order to insure the success implementing a participatory decision-making program, a macroergonomics perspective should be taken.
Progress in Mental Workload Measurement
Authors: Moray Neville , Turksen Burhan , Aidie Paul , Drascic David , Eisen Paul , Kruschelnicky Eugene , Money Laura , Schonert Harry , Thornton Craig
Published: January 2012

Two new techniques are described, one using subjective, the other physiological data for the measurement of workload in complex tasks. The subjective approach uses fuzzy measurement to analyse and predict the difficulty of combinations of skill based and rule based behaviour from the difficulty of skill based behaviour and rule based behaviour measured separately. The physiological technique offers an on-line real-time filter for measuring the Mulder signal at 0.1 Hz in the heart rate variability spectrum.
The Effects of Graphics and Cognitive Style on Managerial Decision Making
Authors: Robless Robert , Bottoms Glen , Lister Mark , Barfield Woodrow
Published: January 2012

This article describes an experiment that examined the effects of two versus three-dimensional graphs for two modes of information presentation, paper or computer, for a managerial decision-making problem. The effects of these variables on the problem solving strategies and cognitive styles of experienced and non-experienced decision makers were also examined. The experimental results indicated that solution times were faster for computer than for paper presentations of information, no significant effects for dimensionality were found, and there was no significant correlation between solution time and cognitive styles (visual acuity, Myers-Briggs test) across modes of information presentation.
Human Factors Issues in Military System Design
Authors: Poters Joseph I.
Published: January 2012

A definition of the elements of human factors is provided to facilitate an understanding of the human factors issues across the military services. Issues for symposium discussion are raised in three broad categories: policy, management, and technology.
Research on Speech Processing for Military Avionics
Authors: Moore Thomas J. , McKinley Richard L.
Published: January 2012

The Biological Acoustics Branch of the Armstrong Aerospace Medical Research Laboratory (AAMRL) is engaged in research in a number of speech related areas. This paper will describe the approach used to conduct research in the development and evaluation of military speech communication systems, mention the types of studies done using this approach and give examples of the types of data generated by these studies. Representative data will also be provided describing acoustic-phonetic changes that occur when speech is produced under acceleration.
Computers and Productivity: A Human Factors Viewpoint
Authors: Carpenter Raymond , Riley Michael W.
Published: January 2012

The use of computers as a productivity improvement tool for “knowledgeworkers” is examined. Limitations of the human factors engineering analysis of work station design for the knowledgeworker are developed. Suggestions for future research directions are made.
Human Factors Design Criteria for Spaceflight Intravehicular Crew Restraints
Authors: Lewis Ruthan
Published: January 2012

Proper design of devices to restrain and position astronauts in microgravity is essential for working and living in space. This paper traces the development of crew restraints throughout the history of the U.S. space program. The paper also examines the functioning of various restraints in their conditions of use. Finally, design issues and recommended design guidelines for intravehicular crew restraints are identified.
Over-the-Ear Industrial Hearing Protectors: An Assessment of Comfort Issues
Authors: Casali John G. , Lam Siu T.
Published: January 2012

A self-report methodology was developed for evaluating perceived comfort and related wearability issues among non-earplug hearing protection devices. Rating scale and ranking procedures were completed by fifty subjects after wearing four different noise-attenuating earmuffs and two ear canal caps. The methodology reliably distinguished among different earmuff types and earcaps on a variety of comfort-related measures, as determined by non-parametric statistical analyses. In general, over-the-pinna muffs were found to be more comfortable than over-the-ear canal earcaps, and some muff designs were preferable to others. The earmuffs were also ranked as easier to don than earcaps. It is critical that comfort be a prime consideration in hearing protection device design because it greatly influences the amount of time the device will be worn in the workplace.
Are we Boxing Ourselves in with the UIMS Box?
Authors: Lovgren John E.
Published: January 2012

A User Interface Management System generally separates the design space for the interface and the application. This separation may have been useful as a means for improving our understanding of interfaces, but does it really support the design of good application interfaces and more importantly good application interface styles?
Designing Airline Passenger Safety Cards
Authors: Schmidt John K. , Kysor Kragg P.
Published: January 2012

The field of human factors endeavors to optimize and standardize interfaces in an attempt to achieve the best fit possible, to include the design of instructional material. The authors have observed that airline passenger safety cards vary greatly in layout, construction, etc. and could benefit from quidelines presented in the pertinent literature. The present effort examined both user preference as well as card effectiveness. It was found that cards which implement recommended techniques are more preferred and effective than those that do not.
The Evolution and Maturation of Operational Teams in a Training Environment
Authors: Salas Eduardo , Morgan Ben B. , Glickman Albert S.
Published: January 2012

Several models of team development were synthesized from the team performance/team training literature as the basis for a working model of Team Evolution And Maturation (TEAM). The TEAM methodology is designed to investigate the development of teamwork during training of operational teams. The TEAM model suggests that the life cycle of a team consists of as many as seven developmental stages. The theoretical foundations and description of the model are discussed as well as its relevance to team training.
Classification of Multidimensional Data under Time Constraints: Evaluating Digital and Configural Display Representations
Authors: Boulette Margery D. , Coury Bruce G. , Bezar Nadeem A.
Published: January 2012

The purpose of this research was to evaluate differences in processing ability between integral and separable representations of process control data under conditions of time constraints. Subjects were trained as “operators” to identify system states and subsequently participated in time constrained (100%, 50% and 25% paced) sessions. Findings revealed that operators in both display conditions were able to respond significantly faster (while maintaining fairly high degrees of accuracy) under 100% and 50% time constrained conditions than in self-paced conditions. Classification accuracy suffered more for the separable than the integral display during the 25% paced condition.
Failure to Identify “Identifiable” Sounds
Authors: Ballas James A. , Dick Kristin N. , Groshek Mary R.
Published: January 2012

The identifiability of sounds used in the Meaningful Sounds Identification test was measured. Identifiability was quantified with a measure of identification uncertainty. Calculation of this measure involves sorting the identification responses into categories of similar causes. Two exemplar sets of the sounds were used and the response data were analyzed separately by two sorters. All of the sounds were not highly identifiable, as was expected given the use of the test. The results were comparable for the two set of exemplars, and for the two sorters. The results demonstrate the importance of quantifying sound identifiability.
The Development of a Response Sequence: A New Description of Human Sampling Behaviour with Multiple Independent Sources of Information
Authors: van Delft Jan H.
Published: January 2012

In almost every process control situation the human supervisor has to attend many sources of information. With large numbers of information sources the supervisor is forced to divide his attention and to acquire information through sampling. In the 60′s and 70′s several models of sampling with different criteria for optimal behaviour, have been proposed. Behavioural data indicate, however, that human monitoring behaviour can show large deviations from optimality. To account for these deviations a new model based on sequential sampling, is proposed. Experimental testing of this model reveals the development of fixed sampling sequences and the choice of a time base for execution as important performance shaping factors.
Ergonomic Considerations in Robot Selection and Safety
Authors: Wygant Robert M. , Donaghey Charles E.
Published: January 2012

This paper will review the major physical features of humans versus robots that are important in the evaluation, selection, and safe operation of robots for industrial tasks. A model for robot performance is presented and the methods for predicting the time a robot takes to complete a task will be discussed.
Special Session: Intelligent Tutoring and Help Systems
Authors: Smith Philip J. , Soloway Elliot , Carroll John
Published: January 2012

In recent years, considerable effort has been focused on the development of computational models of expert human performance. One class of expertise that has been studied is that of human tutors. The resultant intelligent tutoring systems are intended to provide the user with the “instructional advantage that a sophisticated human tutor can provide,” (Anderson, Boyle and Reiser, 1985).

This line of research is of interest to the human factors community for two reasons:

1. Intelligent tutoring systems offer potential tools for use in training and educational programs, a long-standing area of interest to human factors researchers and practitioners; 2. There are many human factors and human performance issues that should be addressed in the design of such tutoring systems.

The speakers in this special session will provide an overview of research issues in the design of intelligent tutoring systems. Relevant conceptual issues and approaches will be highlighted in the context of a variety of application areas. Included will be a discussion of the “use of intelligent system monitors that allow users to integrate the time and effort spent on learning with actual use of a system”, (Carroll and McKendree, 1987).
Using the User's Intelligence to Design Intelligent Interfaces
Authors: Carroll John M.
Published: January 2012

To design intelligent interfaces it can be useful to start from a consideration of what users already know and expect to do. This is not the only way to design intelligent interfaces and in fact not the typical method in practice. Several examples are discussed to urge that current practice be broadened to correct this.
Human Factors Engineering Planning Aid
Authors: Merriman Stephen C.
Published: January 2012

This paper describes the application of affordable program management software to the task of planning human factors programs conducted in support of complex system developments. A model of the military system acquisition process was developed and a model human factors engineering program was overlayed upon it. Interdependencies were created between the models so that changes made in the acquisition schedule would cause the human factors program to be automatically tailored. This approach has potential to reduce planning time and increase the quality of human factors plans.
Factor Structure of the Criterion Task Set
Authors: Schlegel Robert E. , Gilliland Kirby , Schlegel Betina
Published: January 2012

A large-scale experimental study was conducted involving the training and testing of 123 human subjects on the Criterion Task Set (Version 1.0). Testing was performed under baseline and stressor conditions. The performance data and Subjective Workload Assessment Technique ratings for the first baseline trial (Trial 6) were analyzed using the SAS VARCLUS procedure to evaluate the structure of the CTS. Seven clusters of response time variables were identified for the nine tasks. In general, the Memory Search, Linguistic Processing and Mathematical Processing tasks were grouped in one cluster with each of the other clusters representing a single task. Five clusters were identified for the SWAT ratings with clusters differentiated along the dimensions of task difficulty and processing stage.
Exploratory Biomechanical Studies to Determine Worker Fitness for Manual Material Handling Tasks
Authors: Hungerford John C. , Johnson Baron P.
Published: January 2012

This paper presents the results from two biomechanical studies that examined the effects of loading on the L5/S1 area of the lower spine. The objective of these exploratory studies was to determine whether subject, cardiovascular, and isometric and isotonic strength variables could be used to determine a worker's risk potential for back injury. The first study examined trunk velocity and torque developed in movement against a 30 lb. resistive load for two groups of people: (1) normals (no back pathology), and (2) abnormals (people with physician-diagnosed back pathology). Significant differences were found between these two groups for back torque and velocity measures. People with back pathology developed less torque and were slower in their movements. Discriminant analysis provided an 82% correct classification for normals and abnormals using velocity and torque measurements. The second investigation studied only people with back pathology and its objective was to explore the sensitivity of the testing procedure to distinguish between different degrees of back pathology. The purpose of these studies was to develop measures that could be used to screen and place people in jobs so they would not be at risk for back injury. Further work will aim at: (1) improving the discriminant function used in the first study, (2) searching for additional measures predictive of back injury risk potential, (3) reducing the resistive loads used in testing, and (4) studying non-symmetrical loading effects on the spine.
The Effects of Seam Height, Scaling Method, and Bar Weight Distribution on Scaling Effectiveness and Electromyographic Activity
Authors: Lavender Steven A. , Marras William S.
Published: January 2012

Scaling bars are frequently used in underground mining for removing loose material from the roof and the walls. Previous research has demonstrated the scaling bar to be one of the hand tools more frequently involved in underground mining muscular-skeletal injuries. The present experiment investigated the role of seam height, scaling method and selected parameters of scaling bar design. Fourteen subjects worked in simulated mine environment and participated in all conditions of the experiment. Electromyographic (EMG) data was collected to study the relative involvement of six trunk muscles, and dynamometer output measured subjects' ability to use each bar and method effectively. Results suggest the parameters of weight and weight distribution to be important in scaling bar design. Also EMG data showed differences with tool parameters and the method used. Asymmetric loadings to the spine were found to be more extreme in the low roof conditions. These results suggest recommendations concerning tool design and proper training.
A Method for Correcting Biases in Risk Perception
Authors: Godfrey Sandra S.
Published: January 2012

Research in the area of risk perception has shown that people consistently underestimate common risks and overestimate rare ones. This tendency could have an undesirable effect on behavior in potentially hazardous situations. An imaging method was employed for the purpose of changing the perceived risk of a group of potential hazards. The hazards were coffee maker, lawn mower, pesticide, bicycle, power saw, toaster, asbestos, and swimming pool. Subjects sketched cartoons or scenarios of themselves having an accident involving each of a subgroup of the hazards. Subjects rated the risk of each hazard to themselves and estimated injury frequencies for the general population both before and after they sketched the accident scenario. They also rated the hazards on a variety of dimensions such as severity, plausibility, familiarity, imageability, etc. The results indicate that certain characteristics of the hazard determine how likely the risk perception is to change when accident scenarios are made cognitively available.
Visual Display Factors Contributing to Simulator Sickness
Authors: Hettinger Lawrence J. , Nolan Margaret D. , Kennedy Robert S. , Berbaum Kevin S. , Schnitzius Kevin P. , Edinger Katrina M.
Published: January 2012

The history of research on visually-induced illusory self motion, or vection, has demonstrated that in many instances observers have experienced disturbances similar to those of motion sickness. Visual displays in flight simulators may also produce the experience of vection, and illusions of self motion are likely to become more common with the increased use of wide field-of-view presentations of realistic imagery. Many of the disturbances observed in laboratory studies of vection have also been found in simulators, and are likely to become more common. This paper presents a background to the study of visual-vestibular disturbances associated with illusory self motion in flight simulators, and an overview of current experimental efforts aimed at identifying the causal factors.
Knowledge Aided Display Design (KADD) System: An Evaluation
Authors: Hunt Ruston M. , Frey Paul R.
Published: January 2012

The development and evaluation of the Knowledge Aided Display Design (KADD) system is described. Developed to investigate several designer support concepts in the context of the design of computer-generated displays, KADD's implementation uses technology from several disciplines of computer science including data base design and management, graphics, expert systems, and real-time simulation. This paper discusses KADD's goals and concepts, the implementation of the system, and the results of a two-part evaluation to determine the effectiveness of the KADD concepts.
A Study of Human Performance in a Sewing Task
Authors: Montazer M. Ali , Vyas Suresh K. , Wentworth Ronald N.
Published: January 2012

A study of human performance on sewing machines was undertaken by looking at a simple straight-stitch sewing task. The primary purpose of the study was to investigate whether sewing tasks could be described by a self-paced movement control model. A sewing experiment was conducted with six female subjects. The factors considered were Subjects, Sewing zone tolerance, Fabric type, and Stitch rate. Sewing time per trial and errors were recorded. The results of ANOVA on sewing speeds showed significant effects for all the main factors. The significant sewing zone tolerance is in agreement with the results of previous studies of movement control where the tasks were line drawing, forklift truck driving, and beam walking. The relationship between the sewing speed and the sewing zone tolerance was found to be linear with ρ = 0.963, which proves the applicability of a self-paced movement control model to sewing tasks. The slope of this relationship can be viewed as a measure of task controllability as it quantifies some of the factors involved. The slope can further be used to observe the speed penalty for defining tighter and more accurate sewing tolerances.
Optimizing Visual Search and Cursor Movement in Pull-Down Menus
Authors: Francik Ellen P. , Kane Richard M.
Published: January 2012

A de facto standard is emerging for the design of pull-down menus. A set of menu items is presented to the user, with temporarily unavailable items listed in a lighter, “grayed-out” font. This ensures the consistent location of each item, but requires the user to visually scan over and possibly move the cursor through extra items that cannot be selected. Previous research has shown that both location and number of items affect users' ability to select items in menus. We examined the tradeoff between these factors by evaluating an alternative in which inactive items are deleted instead of grayed out. Deleting inactive items resulted in faster menu item selection than did graying them out.
Stopping Performance in Familiar and Unfamiliar Vehicles
Authors: Ranney Thomas A. , Pulling Nathaniel H.
Published: January 2012

Lack of vehicle familiarity is a contributing factor in motor-vehicle accidents. It may also contaminate results in experiments where subjects are required to drive unfamiliar vehicles or driving simulators. An instrumented driving range, including a signalized intersection, was developed to evaluate driving performance in subjects' own vehicles. Fourteen drivers completed approximately fifty laps of the one-half mile closed course in their own vehicles and in an unfamiliar passenger van. Their task was to stop at the stopline following the change of the traffic signal from green to yellow. Brake reaction time, smoothness of deceleration, approach speed, and stopping accuracy were recorded. In the unfamiliar van, brake reaction times were faster and drivers were more likely to stop considerably before the stop line than in their own vehicle. Deceleration was slightly smoother in the unfamiliar van. Individual differences in approach speed were stronger than differences associated with vehicles. Overall performance was influenced more by the position of the vehicle at yellow onset than by vehicle familiarity. Results were interpreted as suggesting heightened driver awareness in the unfamiliar vehicle. Implications for the safety of drivers in unfamiliar vehicles are discussed. The use of unfamiliar vehicles in driving performance research and problems of data analysis resulting from the use of drivers in their own vehicles are also discussed.
Heart Rate Averages as Workload/Fatigue Indicators during OT&E
Authors: Rokicki Stephen M.
Published: January 2012

The purpose of this methodology is to allow a macro-level assessment of workload during long duration test flights without interfering with aircrew duties or imposing non-mission workload by using subjective methods. Using this method allows an initial analysis of heart rate data, mission profile, and mission tasking to indicate areas of concentration for micro-level workload data collection and analysis. Initial results of this method indicate that this use of cardiovascular data does highlight unanticipated workload areas for further evaluation.
Handgrip Strength with the Bare Hand and in the NASA Spacesuit Glove
Authors: Roesch J. Richard
Published: January 2012

This study examined handgrip strength with the bare and spacesuit-gloved hand, in three hand and two elbow positions. Sixteen subjects from the suited-subject pool at NASA/Johnson Space Center gripped a hand dynamometer encased in a vacuum chamber designed to simulate the pressure differential of the spacesuit in space. With the bare hand (at one atmosphere), there was an effect for hand position and a hand-position x elbow-position interaction. With the spacesuit-gloved hand, there was only an effect for hand position. Two different pressure differentials (psid) were used: the glove at 0.5 psid was responsible for a 35% grip decrement (when compared to bare handgrip); the glove at 4.3 psid (normal operating pressure) was responsible for a 42% grip decrement. Bare and gloved-handgrip were positively correlated with hand size, body weight, height, and forearm circumference. Post-hoc, subjects were grouped by hand size; the four subjects in the XL hand-size group lost an average of 17% in grip in the glove at 4.3 psid (when compared to the glove at 0.5 psid); the L group lost 12%; the M group lost 9%; and the S hand-size group lost less than 1%. The larger the hand, the greater was the grip strength decrement due to increased pressure in the glove.
Use of Infrared Telemetry as Part of a Nonintrusive Inflight Data Collection System to Collect Human Factors Data
Authors: Micocci Angelo J.
Published: January 2012

This paper presents the rationale for development and use of an infrared (IR) telemetry device as one portion of a Nonintrusive Inflight Data Collection System (NIDCS). The NIDCS is comprised of three data-collection methods which will be evaluated in concert with each other to present a comprehensive story of Human Factors issues involved in spaceflights and the determination of solutions for these problem areas.
Habitability in Long-Term Space Missions
Authors: Mount Frances E.
Published: January 2012

Given its objective of being permanent and manned, the United States Space Station should be planned, designed and built to maximize the crew's contribution to space station effectiveness.

This paper presents an overview of some of the activities, both in progress and completed, covering the concerns of crew habitability and crew productivity for the proposed United States Space Station.

Various methods and tasks have been incorporated to increase the data base of man/systems information. This information will enhance habitability and crew performance during our Space Missions.

A synopsis of some of the activities, designed to add data for the enhancement of the man/systems component of the proposed space station, is given.

The Man-Systems Division of NASA, Johnson Space Center, Houston, has been the center-point for all the activities listed.
Measuring Pilot Workload in a Motion Base Simulator: III. Synchronous Secondary Task
Authors: Kantowitz Barry H. , Bortolussi Michael R. , Hart Sandra G.
Published: January 2012

This experiment continues earlier research (Kantowitz, Hart, & Bortolussi, 1983) conducted in a GAT-1 motion-base trainer to evaluate choice-reaction secondary tasks as measures of pilot workload. The earlier work used an asynchronous secondary task presented every 22 sec regardless of flying performance. The present experiment uses a synchronous task presented only when a critical event occurred on the flying task. Both 2- and 4-choice visual secondary tasks were investigated. Analysis of primary flying-task results showed no decrement in RMS error for altitude, indicating that the key assumption necessary for using a choice secondary task was satisfied. Reaction times showed significant differences between Easy and Hard flight scenarios as well as being able to discriminate among flight tasks.