bluuebunny/crossref_metadata_2025 huggingface dataset:
Validation of User Models for Interactive Editing
Authors: Folley Lisa J. , Williges Robert C.
Published: January 2012

Although interactive computer editors are an integral part of today's growing computer systems, their design is often determined by tradition or designer intuition, rather than empirical evidence of what is best for the user. In a previous study, Folley and Williges derived naive and expert user models by use of a clustering algorithm. This study tested these models in an actual interactive editing environment. Analysis of variance results showed that subjects did not perform significantly better on the appropriate model editor. A cluster analysis showed low agreement between subjects and with the original models. Differences in command frequency counts between the paper-pencil and interactive editing environments suggest that deeper aspects of interactive editing, such as mode change and current line location, must be included in the user models. It is suggested that interactive editors will more closely conform to user models as they more closely simulate the paper-pencil editing environment.
Operator Corrections during Text Entry with Word Processing Systems
Authors: Neal Alan S. , Emmons William H.
Published: January 2012

In order to answer questions related to keying errors and operator corrections, performance data were collected on typists as they keyed text into a simulated word processing system. Data are presented on the frequency of error detection, the amount of time spent correcting errors, the number of characters erased per error correction, and the types of errors corrected. Comparisons are also made between operator corrected and uncorrected errors.
An Experimental Evaluation of Input Field and Cursor Combinations
Authors: Savage Ricky E. , Habinek James K. , Blackstad Nancy J.
Published: January 2012

Combinations of cursors and display input field indicators were evaluated using three simulated operator tasks. Input fields were indicated by column separators, reverse image, underscoring, or brackets; cursors by blinking or nonblinking underscore or block cursors. Results showed column separators, broken line underscoring, and block cursors to be generally superior to the alternatives.
Keying Logics for Alphanumeric Keyboards and Human Performance
Authors: Butterbaugh Larry C.
Published: January 2012

Four keying logics for the entry of alphanumeric characters were evaluated for keying speed and accuracy. The logics were selected based on their compatibility with current keyboard designs being used for the pilot-aircraft interface with communication, navigation, and other aircraft subsystems. A logic utilizing individual keys (36) for alphanumeric character keying was significantly faster than three other logics which used push-button matrix (telephone) keyboards. All logics were equally accurate, with an error rate of approximately .5 percent. Significant performance differences among the three matrix keyboard logics were inconsistent.
Task Analysis of Nuclear Power Plant Control Room Crews Data Collection Approach and Methodology
Authors: Burgy Donald C. , Newell William J. , van Cott Harold P.
Published: January 2012

This paper describes the data collection approach and methodology used to conduct a task analysis of nuclear power plant control room crews. The objective of the research project, funded by the NRC Office of Nuclear Regulatory Research, is to provide task data for evaluating six areas: (1) Human engineering designs of new control rooms and retrofitting of current control rooms, (2) The numbers and types of control room operators required with requisite skills and knowledges, (3) Operator qualification and training requirements, (4) Normal, off-normal, and emergency operating procedures, (5) Job performance aids, and (6) Communications. The task analysis methodology used in this project is discussed and compared to traditional task analysis and job analysis methods. A data collection approach is described which focusses on a generic structural framework for assembling the multitude of task data that will be observed. Control room crew task data is observed and recorded within the context of an “operating sequence.” The data collection will be conducted at eight power plant sites by teams comprised of human factors and operations personnel. Plants were sampled according to NSSS vendor, vintage, simulator availability, architect-engineer, and control room configuration. The results of the data collection effort will be compiled in a computerized task data base. Preliminary discussion of illustrative examples to demonstrate suitability for data analysis will be presented.
Critical Human Factors Issues in Nuclear Power Generation and a Recommended Comprehensive Long Range Plan
Authors: Hopkins Charles O. , Snyder Harry L.
Published: January 2012

A comprehensive long range human factors plan for nuclear reactor regulation was developed for the U.S. Nuclear Regulatory Commission by a Study Team of the Human Factors Society. This Study Team was selected by the Society to provide a balanced, experienced human factors perspective to the application of human factors scientific and engineering knowledge to nuclear power generation.

The Study Team identified and analyzed areas of human factors concern in nuclear power generation. It reviewed and evaluated current and planned human factors activities and programs throughout industry and the Nuclear Regulatory Commission. The result was a recommended comprehensive human factors plan for the next ten years.
Legibility Comparison of 7 by 7 and 7 by 9 CRT Character Dot Matrices
Authors: McTyre John H.
Published: January 2012

The System/23 Datamaster CRT was designed to use a 7 by 9 character matrix. German standards indicate that the 7 by 9 matrix is unacceptable for use in the office sector. To accommodate the German standards a smaller (7 by 7) character matrix was developed. The present study was conducted to determine the effect of character matrix size on the legibility of CRT Displays. Two types of etched surface CRTs (nonglare) were also tested. The results indicated that neither size of character set nor type of CRT was found to have a significant effect on legibility.
Organizational Considerations in the Design and Implementation of Computerized Decision Support Systems
Authors: Zakay Dan
Published: January 2012

The implementation of a Decision Support System into an organization triggers a process of organizational change. This process of change is analyzed, and it is concluded that coping with it successfully is a basic requirement for the acceptability of the system by the organization. Guidelines are suggested for dealing with this process of organizational change.
Performance Tests for Repeated Measures: Moran and Computer Batteries
Authors: Bittner Alvah C. , Carter Robert C. , Krause Michele , Kennedy Robert S. , Harbeson Mary M.
Published: January 2012

This investigation was directed at the statistical baseline evaluation of nine tasks from two test batteries for suitability for repeated measures applications to environmental investigations. In the first study, five tasks from the Moran Battery were administered to 18 subjects daily for 13 work days. In the second study, four tasks from the Carter and Sbisa Computer Generated Battery were administered daily to 17 subjects (12 in common with first study) for 15 work days. Examination of the means, variances, interday reliabilities and cross-task correlations led to the recommendation of four tasks for repeated measures applications: Vertical Addition, Perceptual Speed, Grammatical Reasoning, and Flexibility of Closure.
Development of a Generic Operator Aiding and Training System
Authors: Hanson Terrance G.
Published: January 2012

A blend of recent technological innovations has provided the capability for a new generation of operator aiding and training systems. This paper discusses the development of one such system - a multi-purpose, computer-based system that permits real-time user interaction with custom designed training and/or decision aids. The system is built around a laser video-disc player which provides the capability for random access of video imagery which can be combined with computer-generated graphics on a color monitor. The audio signal is stored on an audio disk system that also permits random access to real speech segments. System software is designed with the flexibility to permit the production and integration of video, audio, graphics and text information which can be made available to the user through different accessing schemes, for example, paging, selection from a menu, embedded in operating/maintenance procedures, or through highly interactive decision-making routines. The system under development is being used to explore and demonstrate a wide range of applications in the utility, process control and commercial industries. Video-disc techniques of surrogate travel, interactive instruction, and spatial data management are under investigation as potential aids to the operator/maintainer of large complex systems. This paper discusses the potential system applications and also evaluates the advantages and limitations of the component technologies for the human-machine interface.
Effect of Perceived Threat on Avoidance Maneuvers Selected While Viewing Cockpit Traffic Displays
Authors: Smith J. D. , Ellis Stephen R.
Published: January 2012

Ten airline pilots rated the collision danger of air traffic presented on cockpit displays of traffic information (CDTI) while they monitored simulated departures from Denver. They selected avoidance maneuvers when necessary for separation. Most evasive maneuvers were turns rather than vertical maneuvers. Evasive maneuvers chosen for encounters with low or moderate perceived collision danger were generally toward the intruding aircraft. This tendency lessened as the perceived threat level increased. In the highest threat situations pilots turned toward the intruder only at chance levels. Some of the implications of the pilots' turning-towards tendencies are discussed with respect to automatic collision avoidance systems and coordination of avoidance maneuvers of conflicting aircraft.
Quantitative Evaluation of Human Reliability for Operating Tasks in Nuclear Power Plants
Authors: Metwally A. Mohsen M. , Sabri Zeinab A. , Adams S. Keith , Husseiny Abdo A.
Published: January 2012

Human reliability can be computed quantitatively provided that the operational data are put in the proper format and several information matrices are available.

Both one dimensional and multidimensional trends can be easily determined by counting the number of operational errors that belong to one or more specific categories. Two examples are given for one dimensional trends in the operational tasks in 65 nuclear plants over a period of ten years. In the first example, the classification of events is made according to the cue used in error discovery. The results show that observation of unannunciated displays represents 41% of the total number of discovery cues. The second example shows that by classification of events according to the human failure mode, 50% of the total operation errors are due to omission. Recommendations and restrictions are given in detail.

Assuming a constant failure rate (w.r.t. time) and an exponential human reliability model, failure rates (per hour and per demand of frequency of use) for valve mispositioning in two nuclear systems are computed.

Comparison of the results obtained with other estimates of human error probabilities is made. Also, the results show that the unavailability of valves in those systems where human errors involved mispositioning is not significantly greater than that due to mechanical causes.
Individual Differences and Stimulus Discriminability in Visual Comparison Reaction Time
Authors: Dupree David A. , Wickens Christopher D.
Published: January 2012

Individual subjects' reaction time functions in a simple visual comparison task were found to be substantially correlated with measures of spatial ability. In an additional task requiring responses to target stimuli flanked by stimuli associated with competing responses, a sample of high spatial subjects showed little deficit in performance, while a sample of low spatial subjects showed large deficits in performance compared to reaction time to a target stimulus presented alone. These results were interpreted in terms of the interaction between human aptitude and task requirements. The experiments reported are part of an ongoing investigation of spatial ability and visual information processing.
The Effects of Noise on Performance of a Visual Discrimination Task
Authors: Gawron Valerie J.
Published: January 2012

The effects of noise on visual discrimination performance was investigated. Eight subjects performed a line-judgment task at three levels of noise (55, 70, 85 dBA) and two levels of task complexity (single and dual task). Although there was no reliable effect of noise on visual discrimination performance (i.e., speed and accuracy), there was, however, a reliable task complexity effect: single-task (task performed alone) average response time was reliably shorter than dual-task (task paired with itself) average response time.
Development of Sensitive Performance Measures for Selection of Crews for Flight Training
Authors: Connelly Edward M. , Shipley Brian D.
Published: January 2012

Performance of operator controlled systems is limited by our ability to measure system and component subsystem performance in a reliable and sensitive manner. Without adequate performance measures, there is no way to produce and test system designs, plan and execute training systems, or evaluate operational systems. Methods of developing these performance measures can be characterized by the way in which performance criteria are obtained.

One approach which can be used when all factors that limit performance are known and quantified is an analytical method. For example, if a problem requires that an aircraft climb to a specified altitude while conserving fuel during the climb, the criterion, i.e., minimization of fuel, could be precisely defined analytically. Frequently, however, problems cannot be solved analytically, but demonstrations of superior as well as less than superior performances are available. In these cases an empirical approach can be used. This paper describes an empirical method for analyzing simulator flight data to develop weightings that permit performance discrimination between two groups of student pilots (one group of students successfully passed the initial Army rotary wing training program at Ft. Rucker, Alabama. The other group of students did not pass that training course.).

The paper provides a description of the job sample (flight training) tests used to collect the data, the method for synthesizing the performance measures, and the results from using the measures to score student pilots.
Human Factors Concerns in Industrial Robot Applications
Authors: Deivanayagam S.
Published: January 2012

Industrial robot population has been growing at a fast pace during the last decade. With the impending technological breakthroughs, the number of industrial robots is expected to grow at a much higher rate. This paper addresses certain human factors issues that must be considered before and during the installation and operation of a robot work system.
Task Analysis of Spent Nuclear Fuel Operations Technicians
Authors: Hottman Stephen B. , Bateman Robert P.
Published: January 2012

This paper presents the results of a task analysis of operations technicians at an independent spent fuel storage installation (ISFSI). Supervisors at the ISFSI were interviewed and a preliminary job analysis was used to determine required operator skills. Training, safety, operating documents and checklists were reviewed and task inventory forms were developed with the help of ISFSI supervisors. Operations technicians were then interviewed and the task inventory forms filled out with information on task frequency, difficulty, hazard, time to complete, and error potential. These data were analyzed to determine required operator skills and proficiency levels necessary for safe ISFSI operation. The training and testing for certification necessary to verify the skills and proficiency levels were inferred from the data base and the Morris operation records.
Impacts of Technology upon Organizational Design and Management
Authors: Brown Ogden
Published: January 2012

The technical and social systems which make up any organization are interrelated. The dictates of technology can make working relationships and work environments in any one organization significantly different from those of any other organization, and especially so when technological change occurs. Success of the organization thus depends upon the “goodness of fit” between the technical and social systems of the organization, and upon its ability to adapt when changes in technology impact upon the organization. This symposium addresses some consequences and effects of changing technology upon the design and structure of the organization and the ways in which it is managed. Time will be available for audience interaction and questions.
Visual Simulation Requirements for Aircraft Aspect Recognition at Real World Distances
Authors: Kennedy Robert S. , Collyer Stanley C. , May James G. , Dunlap William P.
Published: January 2012

A research program is underway whose goal is to provide engineering guidelines on target image sufficiency for training tactics and maneuvering skills in ground based flight simulators. A preliminary experiment was carried out in the Naval Training Equipment Center's Visual Technology Research Simulator (VTRS), using computer-generated aircraft images displayed on a dome via a variable-resolution target projector. The experiment examined aspect recognition sensitivity, or the distance at which subjects could determine the orientation of another aircraft.

For our initial effort, the aspect (orientation) recognition task was simplified in the following ways: a) on each trial one of only 16 stationary target orientations of a TA4J aircraft was presented, b) targets had the same length/width ratio; c) subjects made binary up/down judgments; d) a staircase method provided thresholds for aspect recognition range. Four different target luminances, and three background luminances were combined with four different levels of projector resolution in a partial parametric study to assess the relative effects of contrast, resolution and brightness.

All main effects were found to be significant. Over the ranges studied, contrast accounted for the most variance and brightness the least. In the best condition studied, aspect recognition was performed successfully at >4 miles (a 5.5 arc minute target), whereas the most degraded condition showed thresholds at 1.5 miles (a 14 arc minute target). These are comparable to distances known to be required in outdoor training ranges and in combat. An additional finding is that reliable subject differences were substantial (>20% of the total accounted for variance). The four subjects who were tested in this study had normal or better vision by static and dynamic tests of contrast sensitivity. Individual differences in these subjects' contrast sensitivity scores were predictive of their visual performance on this target aspect recognition task. These data are discussed from the standpoint of the utility of this paradigm for providing guidelines for training equipment design.
Effects of Maintained Blood Alcohol Concentration and Task Complexity on the Operation of a Punch Press Simulator
Authors: Barbre William E. , Price Dennis L.
Published: January 2012

Eight mildly intoxicated and sober male participants (0.0, 0.05, 0.07, and 0.09 percent blood alcohol concentrations) operated a punch press simulator after being at a given blood alcohol concentration for either 27 or 97 minutes. Performance under the longer duration was significantly more productive (yielding a higher percentage of correctly completed parts) than under the shorter duration. Additional analysis indicated significant effects of task complexity and blood alcohol concentration.
The Survival Shelter Environment: Implications for Human Factors
Authors: Rohles Frederick H. , Konz Stephan A. , Bettge Donald
Published: January 2012

A renewed effort is being directed towards the study of behavior in the survival shelter environment. These efforts are a particular concern for the specialist in human factors because they encompass the stressors of temperature, crowding, air quality, food and water restriction, reduced illumination, and power and sleep disturbances - all while the occupants are under severe emotional stress. Human factors problems involve leadership and the selection and training of shelter leaders, work schedules and procedures, the allocation of resources, the monitoring of conditions outside the environment, safety and health, equipment maintenance and problems of communication, shelter management and decision making.

In this forum, the scenario within the survival shelter will be described as a systems oriented problem requiring multidisciplinary solution. Then the environmental stressors will be identified and the behavioral factors will be specified. The discussion resulting from these stimuli should identify voids in the human factors aspects of the survival shelter, in addition to providing FEMA the necessary human factors input they needed for adequately providing for the survival shelter and its effective management.
Pseudo-Quickening: A New Display Technique for the Control of Higher Order Systems
Authors: Gill Richard , Wickens Christopher D. , Donchin Emanuel , Reid Robert E.
Published: January 2012

The concept of the pseudo-quickened display is introduced as a technique for aiding the control of higher order systems. In this display the intensity of the cursor is employed as a cue for optimal switching of manual control input. Performance on this display is compared with performance on an unaided, a quickened, and a phase plane display. Some advantages over the conventional display in performance are demonstrated by all three aided displays. When all aided groups transferred to an unaided conventional display, only those trained with the pseudo-quickened display showed benefits of prior training. This group also performed better than those who trained only with the conventional display.
F-18 Human Engineering Program — a Retrospective View
Authors: Hitchcock Lloyd , Merriman Stephen C. , Moore Julian P. , Field Peter
Published: January 2012

Presentation begins with a review of the F-18 Program - progression from a single place fighter with a crew station the size of the A-4's to a full multi-mission aircraft. Describes Human Engineering design “ground rules” and illustrates the degree to which the actual design conforms. Describes the role of anthropometry in both the crew station and design considerations affecting the maintainer - both airborne WRA's and GSE. New techniques in applied anthropometry are described.

Presents a short review of the simulator and mock-up work accomplished during design and development. A summary of the role and contributions of the U.S. Navy and Marine Corps pilots who participated in the “Aircrew Systems Advisory Panel” (ASAP) is presented. Unique relationships between Human Factors and ASAP are described.

The results of the implementation of a rigorous Human Factors program are shown during flight and ground testing. A summary of contractor, Naval Air Test Center and early operational tests is presented.

Finally, the authors' individual views as to the cost effectiveness of a thorough Human Factors program on a major acquisition such as the F-18 are provided. Recommendations for future programs are also delineated.
Attribute Requirements for a Simulated Flight Scenario Microcomputer Test
Authors: Shannon R. H. , Krause M. , Irons R. C.
Published: January 2012

Eighteen subjects practiced a video game of bombing and air combat maneuvering, Phantoms Five®, on an APPLE® microcomputer for 10 minutes a day for 15 days. The dependent variable was the combined score for number of hits and number of targets. Performance stabilized from Days 8–15 with a pooled reliability of .904. Eight reference tests which theoretically measure cognitive, perceptual, quantitative, and motor skills were selected and used as independent variables. Stabilized performance on these tests was observed after a period of practice which was predetermined from previous experimentation. Attributes of the Phantoms Five® were isolated using a structured job analytic tool (Position Analysis Questionnaire, PAQ). A principal components analysis of the measures that correlated with the dependent variable resulted in a one factor solution explaining 66 percent of the variance. It was concluded that construct validity was established since there was a strong similarity between the attribute requirements attained by correlating the stabilized scores of independent and dependent variables and by the PAQ analysis of task functions.
Human Operator Simulation in the Cognitive Domain
Authors: Glenn F. A. , Zaklad A. L. , Wherry R. J.
Published: January 2012

This paper outlines and briefly discusses some major results of the Human Operator Simulator (HOS) development program. HOS is described as it is currently configured, and some thoughts are presented on the further development of HOS in the cognitive domain.
An Empirical Evaluation of Language-Tailored PDLS
Authors: Boehm-Davis Deborah A. , Sheppard Sylvia B. , Bailey John W.
Published: January 2012

Recent research in the area of program documentation has suggested that using a detailed design written in a Program Design Language (PDL) will lead to superior performance over other formats due to the small amount of translation that is required in mapping from the design to the code. This hypothesis was tested by designing PDLs which reflected the syntax and features of particular programming languages and by examining the performance of programmers coding from these various PDLs in one of two coding languages. The data showed that programmers produced code most quickly from the form of documentation that was closest to the code.
Use of Appropriate Looping Structures: Expert vs. Novice
Authors: Swigger Kathleen , Wallace Layne
Published: January 2012

Studies are currently being initiated to examine the use of techniques based in cognitive psychology to make the knowledge employed by experts easier to obtain and quicker to put into practical application (Ledgard, 1980). Attempts have also been made to establish formal theories about the composition of an expert's knowledge network (Friedman, 1974; Dijkstra, 1976; Wirth, 1977; Soloway, Bonar, Woolf, Barth, Rubin and Ehrlich, 1981), but most of these attempts were based on conjecture with little experimental validation.

The present study attempted to examine these questions with respect to appropriate looping constructs. By employing the same procedures introduced by Soloway, et al. (1981), novice and expert programmers were tested using PL/I. The results of this endeavor provide information to be used in evaluating the actual knowledge possessed by experts and the relationship of this knowledge to the net advocated by Soloway, et al. (1981).
Human Cognition in Man-Machine Systems
Authors: Hale Chris R.
Published: January 2012

The study of the relationship between man and machine has recently witnessed a shift in emphasis from the study of man as a manual controller to the more cognitive aspects of man as a supervisor/monitor. This shift has brought about the need for a rigorous examination of the processes involved in problem solving, decision making, skill acquisition and the control of attention; for each of these cognitive components has profound influence in such diverse areas as command and control, maintenance, crew station design considerations, training, and workload. In order to profit from an examination of these areas, two goals must be accomplished. The first is an understanding of the fundamental processes that are responsible for the behavior of interest. This understanding must exist on both a theoretical and empirical level for genuine insight to be gained. The second accomplishment is that methods must be developed that allow quantitative modeling of these processes. Only in this way can theoretical knowledge of these processes be applied profitably to the man-machine environment.
An Approach for Training Aircraft Night Attitude Recognition Using Microcomputer CAI
Authors: Hottman Stephen B. , Urban Kenneth E.
Published: January 2012

Ten subjects participated in a one-group pretest-posttest experiment designed to define the feasibility of using microcomputer-based computer aided instruction (CAI) to train night aircraft attitude recognition. Statistical analysis shows that significant improvement in scores occurred over the course of the study, but enhancements are still desirable in both the CAI methodology and presentation.
Evaluations of Digital Imagery Processed by Enhancement/Restoration Techniques
Authors: Chao Betty P.
Published: January 2012

This paper investigated the efficacy of digital image enhancement/restoration processes as measured by human performance. The human performance measures consisted of an information extraction task and a subjective scaling task. Various enhancement/restoration processes which addressed image degradations of poor contrast, blur, and noise were selected and evaluated.

The digital images consisted of military and civilian scenes, each of which were degraded by different levels of blur and noise. Ten Air Force photointerpreters participated in the investigation. The photointerpreters viewed the images on CRTs and performed both tasks.

The results indicated that image degradations deterred the quality of digital imagery for interpretation. However, the addition of enhancement/restoration processing improved information extraction performance by 12%. On the other hand, subjective scaling results revealed that processing did not improve nor worsen perceived interpretability of the images.
Future Directions in HF and Computer Systems: A Meeting Report
Authors: Green Paul
Published: January 2012

This panel session will describe what happened at the meeting held in Vail, Colorado, April 11–14, 1983. The purpose of the Vail Workshop was to help decide what the HFS Computer Systems Technical Group and its members should be doing now and in the near future to satisfy the needs of a computer designer in 1995.
A Noise Hazard Evaluation of a Furniture Manufacturing Operation
Authors: DeGusseme Larry M. , Smith Thomas J. , Fadl Samia
Published: January 2012

A noise hazard evaluation was conducted at a wood furniture manufacturing company in the lower mainland of British Columbia, Canadas' most western province. The firm studied was an 8 room plant with a 13 stage manufacturing process. Noise level measurements indicated that the existing 90 dBA (TWA) standard set by the Workers' Compensation Board of British Columbia, was exceeded in 3 main work areas: (1) the wood storage room, (2) the cutting room, and (3) the shaping/lathe room. Audiogram results, for 13 of the 23 workers studied, showed that 10 (77%) had some degree of hearing impairment, and 3 (23%) had normal hearing. Of workers in the former group, 7 (54%) had early warning hearing impairment and 3 (23%) had abnormal hearing loss. A systems analysis of noise sources was carried out to develop noise control techniques at the noise source, path, and receiver.
Voice Feedback Protocols
Authors: Steiner Bruce A. , Burkhart Brenda J. , Berson Barry L.
Published: January 2012

This study was designed to evaluate the relative effectiveness of three different types of feedback (visual, auditory, or both visual and auditory) provided to an operator during a simulated voice controlled weapon launch scenario. The results showed a significant difference between type of feedback used, and indicated how feedback should be provided to an operator.
Opening Jars: An Anthropometric Study of the Wrist-Twisting Strength of the Elderly
Authors: Rohles Frederick H. , Moldrup Kelli L. , Laviana Joseph E.
Published: January 2012

The purpose of this study was to measure the wrist-twisting strength among the elderly. The subjects were 100 men and 100 women whose ages ranged from 62 to 92 years. To measure their wrist-twisting strength a device was developed that consisted of a modified torque-wrench which would accept 8 different container lids whose diameters ranged from 27 mm to 123 mm. Each subject performed the wrist-twisting task on each lid 4 times – twice clockwise and twice counter-clockwise. The results showed that men were stronger than the women, that there was no difference in the torque from a clockwise or a counter-clockwise twist, and that a greater amount of torque could be applied to large diameter lids than to smaller diameter lids. When age, body weight, height, grasp, lateral prehension, and hand length, breadth, and spread were correlated with the wrist-twisting strength it was found that for the men, age, grasp and hand length contributed to torque and for the women, body weight, grasp, and lateral prehension were the main determinants of torque. In addition the torque required to open various commercial products was measured so that by comparing these torque values with those of the wrist-twisting strength it was able to estimate the percentage of men and women who could open a jar of a given diameter and torque.
Individual Differences and Age-Related Changes in Time-Sharing Ability of Aviators
Authors: Braune Rolf , Wickens Christopher D.
Published: January 2012

Performance in single task and dual task configurations was examined across four different age groups to determine the presence of an attention deficit hypothesis with increasing chronological age. Although a general slowing of performance could be shown no interaction between age and dual task loadings could be observed which is interpreted as negative evidence for the attention deficit hypothesis. A separate analysis revealed individual differences in time-sharing ability within age groups to be a significant factor in dual task performance.
Examination of Workload Measures with Subjective Task Clusters
Authors: Derrick William L.
Published: January 2012

Multiple measures of operator workload may fail to agree or dissociate for a given task. This study proposes a new method to examine this dissociation for two categories of workload measures: Subjective ratings and performance-based secondary tasks. Eighteen tasks of differential processing resource demand were performed by subjects and rated according to workload similarity. Additive clustering analysis of the workload ratings produced overlapping task clusters. Three properties–performance, effort, and input complexity-explained the cluster solution. Dissociation was found when tasks perceived as similar in workload did not possess the same properties.
The Effect of Delayed Report on Subjective Ratings of Mental Workload
Authors: Eggemeier F. Thomas , Crabtree Mark S. , LaPointe Patricia A.
Published: January 2012

Forty-eight subjects performed a short-term memory task with several difficulty levels and provided either immediate or delayed ratings of workload via the Subjective Workload Assessment Technique (SWAT). Mean SWAT ratings did not vary significantly as a function of delayed report, but a substantial number of subjects gave delayed ratings that were discrepant from their immediate ratings. A counterbalancing effect in delayed ratings appears to have been a factor in the failure of the delay effect to reach significance. A secondary objective of this study was to examine the sensitivity of SWAT in a between-subjects design. SWAT ratings varied significantly as a function of task difficulty manipulations, supporting the sensitivity of SWAT to the workload of the conditions used.
The Effect of Feedback on Subjective and Objective Measures of Workload and Performance
Authors: Hauser Jan R. , Hart Sandra G.
Published: January 2012

Thirty subjects were employed in a mixed experimental design that examined five levels of feedback and two levels of difficulty for two tasks, with repeated measures on the difficulty and task variables. The amount and type of feedback was varied so that it provided information about performance of the task on the objective measures within a block of trials, or provided the same information at the end of the task (simply providing knowledge of results), and was also varied in quality, either as a comparison to the subject's own average performance of the task, or in comparison to an experimentally determined ‘figure of merit’. Two tasks, each with two levels of difficulty, were used: (1) a task that primarily imposed cognitive demands, a version of the Sternberg memory task, and (2) a task that primarily imposed psychomotor demands, a target acquisition task modelled on the Fitts' Law paradigm. Both objective and subjective measures demonstrated reliable and predictable effects for the difficulty levels of the two tasks, however the tasks were differentially affected by the feedback conditions, but differences between and within tasks were generally small. The relationships between objective measures, and subjective ratings of workload and performance rarely reached significant levels.
Response Times and Traffic Sign Design: Application of the Critical Path and OP Methods
Authors: Fisher Donald L. , Papazian Bruce
Published: January 2012

In many situations a rapid, accurate response to a traffic sign is required. The design of traffic signs which keeps response time at a minimum is an important human factors problem. An understanding of the network of cognitive processes that govern response times can be very useful to the human factors engineer, especially when it is possible to determine which processes, if shortened in duration, would lead to an overall decrease in response time. The design activity can then be focused on keeping at a minimum the duration of these critical processes. Two recently developed methods of response time analysis which make possible the determination of the critical processes are discussed: the critical path method (Schweickert, 1978) and the OP method (Fisher and Goldstein, in press).
A Nuclear Safety Basis for Assigning Priorities to Human Engineering Concerns at Nuclear Power Plants
Authors: Sheehy Edward J.
Published: January 2012

At this point in the integration of human factors into the nuclear power industry an important issue is how are the various discrepancies between the post Three Mile Island operator interface guidelines and the actual control room configuration to be assigned priorities for resolution? While it is generally agreed that safety-related discrepancies should receive first priority, it is not at all clear just what “safety-related” means when considered in an operational sense. This paper describes the current state of evolving standard definitions for hardware oriented safety features. It discusses how these definitions could be expanded to include operationally related considerations and explores some benefits which would ensue. These include (1) establishing a nuclear safety basis which can be used in establishing priorities for resolution of human engineering concerns, and (2) obtaining legal recognition of operational concerns in general in the design and licensing arenas.
Keyboard Design: An Investigation of User Preference and Performance
Authors: Monty Robert W. , Snyder Harry L. , Birdwell Gerald G.
Published: January 2012

This study investigated the effects of several alphanumeric keyboard characteristics including: audible feedback; location, size, and shape of the carriage return key; and the shape and style of keycaps. Four of the six keyboards were experimental prototypes, while the remaining two were production models.

Eighteen subjects were used in a mixed factorial design. Subjects performed a text entry task during which they were not allowed to correct any errors. Four types of data were collected: 1) total errors per trial, 2) total time for text entry, 3) individual preference questionnaire data for each keyboard, and 4) comparative questionnaire data across keyboards. Results indicate that time on task was not significantly different among keyboards; however, with audible feedback, a marginally significant result was found. Highly trained typists committed significantly more errors than did the other two less experienced groups. Subjects indicated that the location, size, and shape of the return key were important factors for keyboard design. Across groups, subjects preferred the capability for audible feedback.
Touch-input Devices: Training the Device or the Operator?
Authors: Beringer Dennis B. , Peterson James G.
Published: January 2012

Although touch-entry devices offer a number of advantages in low-resolution situations, requirements for high-resolution input must take into account the inherent biases and limitations of the operator. After the determination of operator bias in making high-resolution descriminations, attempts were made to examine the applicability of performance models for reducing the amount of “registered” error. It was found that bias error could be reduced, but that individual models are probably necessary for this to be done effectively.
Monitoring Behavior and Process Control
Authors: Hurts C.M.M.
Published: January 2012

As part of a research project concerned with the function of the human operator in semi-automated man-machine systems, the monitoring behavior of the operator carrying out a process control task was investigated. More specifically, a study was made of the way this monitoring behavior changes as a result of using new instrument types or different presentation modes on the control panel. In the present experiment, two display variables were used, the first one being continuous or intermittent presentation of the controlled variables. The second display variable was controlling with or without a predictor instrument. Other independent variables were type of control task and first or second half of the control task. Results show that subjects monitored the controlled variables with longer eye fixations if the predictor instrument was not available. Also, the controlled variables were monitored more frequently in the second half of the control task. However, both effects interacted significantly with type of task. These results are interpreted and discussed in relation to control performance and control task difficulty.
Pilot Workload Factors in the Total Pilot-Vehicle-Task System
Authors: Heffley Robert K.
Published: January 2012

This paper is based on a current study of pilot workload models for crucial Navy flight tasks such as the carrier landing and high-speed, low-level navigation. The objective is to construct a more rigorous and complete view of the overall pilot-vehicle-task system in order to describe how facets of pilot workload can be associated with elements of the system. The purpose of the paper is to discuss workload features in a system context as a first step to developing a more thorough workload prediction process for the design and operation of aircraft.
Quantification of Crew Workload Imposed by Communications-Related Tasks in Commercial Transport Aircraft
Authors: Acton William H. , Crabtree Mark S. , Simons John C. , Gomer Frank E. , Eckel J. Steven
Published: January 2012

Information theoretic analysis and subjective paired-comparison and task ranking techniques were employed in order to scale the workload of 20 communications-related tasks frequently performed by the captain and first officer of transport category aircraft. Tasks were drawn from taped conversations between aircraft and air traffic controllers (ATC). Twenty crewmembers performed subjective message comparisons and task rankings on the basis of workload. Information theoretic results indicated a broad range of task difficulty levels, and substantial differences between captain and first officer workload levels. Preliminary subjective data tended to corroborate these results. A hybrid scale reflecting the results of both the analytical and the subjective techniques is currently being developed. The findings will be used to select representative sets of communications for use in high fidelity simulation.
Time of Day Variations in Steady-State Accommodation to Square-Wave Gratings
Authors: Amerson Thomas L.
Published: January 2012

Time of day variations were studied both in the dark focus of accommodation and in steady-state accommodation. All subjects (n = 16) were measured in the morning and again 12 hr later. The mean nighttime dark focus was 0.5 diopters (D) greater than the morning value. Overaccommodation to far targets (0 D) and underaccommodation to near targets (3-20 D) occurred for both 4.2 and 8.4 cycle/deg square-wave gratings. A shift in steady-state accommodation was found with the nighttime values being somewhat greater (0.25 D) than the morning values.
Load Characteristics and Manual Carrying Capabilities
Authors: Mital Anil , Ilango M.
Published: January 2012

This paper reports the results of an investigation conducted to determine the influence of certain load characteristics on the carrying capabilities of male workers. The effects of load density, location of load center of gravity, and load orientation were studied. Using the psychophysical methodology, subjects determined the maximum weight they were willing to carry in containers of different configuration, over prescribed distances. Statistical analysis of the data showed that load density and its c.g. location significantly influence carrying capabilities of males. The influence of load orientation on carrying capabilities was not critical. A comparison was also made between the carrying capacity of students, employed in this study, and industrial workers. Compared to the industrial population, students carried significantly lower amounts of weight. Since the isometric strengths of the two populations were comparable, age and experience on the job appear to be the logical factors contributing to this difference. The findings of this study were similar to the previous findings for lifting activities.
Personal Factors Affecting Worker Satisfaction and Job Attitudes in Industrial Organizations
Authors: Das Biman , Santos Michael J.
Published: January 2012

The effect of skill level, age and sex on worker satisfaction and job attitudes of blue-collar employees was determined in unionized and non-unionized Mexican industrial companies. The higher skilled workers showed significantly greater worker satisfaction and job attitudes than lesser skilled employees. The older employees demonstrated significantly better worker satisfaction and job attitudes than their younger counterparts. The female employees were significantly higher in worker satisfaction and job attitudes than male workers. The non-unionized employees exhibited significantly greater worker satisfaction and job attitudes than unionized workers.