bluuebunny/crossref_metadata_2025 huggingface dataset:
Measuring Situation Awareness in an Attack Helicopter Domain: An Exploratory Investigation
Authors: Entin Eileen B.
Published: January 2012

We contrasted two methods for assessing situation awareness (SA) in a dynamic, fast-paced military domain, a high-level measure based on subjects' responses to global questions about a tactical situation and a detailed measure based on their answers to questions about specific elements of the situation. We hypothesized that the two measures would be correlated, and while they were initially, as a dynamic simulation progressed, the relationship between the two measures decreased. We also hypothesized that level of SA would be correlated over time, but the two approaches to the assessment of SA lead to different conclusions, with the high-level measure showing a significant correlation while the detailed measure was not correlated across the measurement periods. The internal consistency of the detailed measure also decreased over time, suggesting that SA becomes more fragmented as a dynamic situation develops, and calling into question the appropriateness of measuring SA as a unified concept.
The Effect of Overview Displays on Situation Assessment
Authors: Rivera Diego Y. , Chignell Mark H. , Davey Eric
Published: January 2012

The impact of overview displays when operating in a simulated environment (SimCity 2000) was assessed. Subjects in one condition had access to a fixed overview display on a separate CRT (an additional display that was absent in the no overview display condition). The experimenter operated the simulation based on the verbal instructions of the subjects. More trends were detected, and more verbalizations, in the overview display condition. There was also more discussion of the simulation state and more transitions from commenting about states to preparing actions, with the overview display. It is argued that the methodology used in this study, and the results obtained, demonstrate that measures such as situation assessment may be easier to interpret than performance measures, and less variable, because they are less likely to be influenced by extraneous factors. Thus they may be more sensitive indicators of the effect of changes in display design.
Allocation of Function, Adaptive Automation, and Fault Management
Authors: Moray Neville , Inagaki Toshiuki , Itoh Makoto
Published: January 2012

Sheridan's “Levels of Automation” were explored in an experiment on fault management of a continuous process control task which included situation adaptive automation. Levels of automation with more or less automation autonomy, and different levels of advice to the operator were compared, with automatic diagnosis whose reliability varied. The efficiency of process control and of fault management were explored under human control and automation in fault management, and aspects of the task in which human or automation were the more efficient defined. The results are related to earlier work on trust and self confidence in allocation of function by Lee, Moray, and Muir.
An Ecological Approach to Interface Design
Authors: Flach John M. , Tanabe Fumiya , Monta Kazuo , Vicente Kim J. , Rasmussen Jens
Published: January 2012

Four approaches to interface design are considered: technology centered, user centered, control centered, and use centered (ecological). Each perspective provides unique insights into pieces of the interface design problem. However, it is argued that the ecological or use centered approach provides a more comprehensive framework within which the other three perspectives can play important supporting roles. This approach goes beyond issues of information requirements to address meaning as an emergent property of a dynamic work ecology.
Making Usability Data More Usable
Authors: Gillan Douglas J. , Cooke Nancy J.
Published: January 2012

Usability tests often include recording of users' behaviors as they interact with a computer; unfortunately, these data are often underused for design due to their complexity and the difficulty in interpreting them. In recent years, a variety of methods have been proposed for analyzing user behavioral sequences. In this paper we propose five criteria for evaluating the quality and effectiveness of any such method – (1) standardization and repeatability of the method; (2) simplification of the data; (3) validity; (4) interpretable visual representation of the data that suggests design implications; and (5) output that is amenable to additional analyses. We describe how the PRONET method – an analytical method that uses the Pathfinder algorithm to produce network representations of behavioral sequences – successfully addresses these five criteria. Finally, we argue that test design should be conceived of in a framework of usability engineering, thereby leading to the creation of more usable test methods.
Work Models for Interface Design: Techniques and Applications in Complex Domains
Authors: Vicente Kim J.
Published: January 2012

The modeling of human work is ubiquitous in the cognitive engineering community. Modeling can take many diverse forms, but its goal is always the same: to provide designers with a deeper understanding of the needs of human operators. This understanding becomes ever more critical as work domains increase in complexity because the capability of designers to anticipate all of the needs in all possible contexts becomes less tenable without modeling tools. Why, then, is there such a proliferation of work analysis techniques? Even more importantly, which modeling techniques are most useful for what types of design problems? In this symposium, several papers will be presented describing the application of various modeling techniques to the design of complex work environments. An emphasis will be placed on identifying the modeling techniques that are useful, or not useful, for various types of application domains and for different design goals. The strengths of integrated modeling techniques will be examined as compared with their increased costs. The various presenters will provide guidance for the selection of design problems, the application and payoffs from the modeling effort, and the use of results for design.
Toward an Integration of Task- and Work Domain Analysis Techniques for Human-Computer Interface Design
Authors: Miller Christopher A. , Vicente Kim J.
Published: January 2012

Work analysis techniques are critical, longstanding methods for designers to obtain the knowledge required for good interface design. The majority of current techniques fall into two types: task-centered and system- or work domain-centered. These approaches have different and largely complimentary strengths and weaknesses, but they focus on different aspects of the design problem and a unification is required for completeness. We discuss and compare the characteristics of both approaches. Then we present results and lessons learned from an attempt to integrate two characteristic analysis techniques in analyzing interface requirements for a simple feedwater system: Rasmussen's (1985) Abstraction Decomposition Space (also known as the Abstraction Hierarchy) and Sewell and Geddes (1994) Plan-Goal Graph.
Cognitive Performance for Multiple Operators in Complex Dynamic Airspace Systems: Computational Representation and Empirical Analyses
Authors: Corker Kevin M.
Published: January 2012

This paper presents a set of studies in full mission simulation and the development of a predictive computational model of human performance in control of complex airspace operations. NASA and the FAA have initiated programs of research and development to provide flight crew, airline operations and air traffic managers with automation aids to increase capacity in enroute and terminal area to support the goals of safe, flexible, predictable and efficient operations. In support of these developments, we present a computational model to aid design that includes representation of multiple cognitive agents (both human operators and intelligent aiding systems). The demands of air traffic management require representation of many intelligent agents sharing world-models, coordinating action/intention, and scheduling goals and actions in a potentially unpredictable world of operations. The operator-model structure includes attention functions, action priority, and situation assessment. The cognitive model has been expanded to include working memory operations including retrieval from long-term store, and interference. The operator's activity structures have been developed to provide for anticipation through knowledge of the intention and action of remote operators. System stability and operator actions can be predicted by using the model. The model's predictive accuracy was verified using the full-mission simulation data of commercial flight deck operations with advanced air traffic management techniques.
You can't Teach what you can't Describe: One Experience in Developing CTA Instruction
Authors: Militello Laura G. , Hutton Robert J.B. , Chrenka Jason E.
Published: January 2012

Although over the last several years researchers have demonstrated considerable success in applying CTA methods to design systems, few researchers have been able to articulate what it is they do when they conduct a CTA. If CTA is to continue to have an impact in design projects and CTA methods are to continue to be refined and improved, then we must develop a language that allows us to train others to conduct CTA and to compare and contrast different methods. This presentation will describe a project in which multimedia software was developed to train Navy Instructional Systems Specialists to conduct a streamlined CTA. Issues that arose in our struggle to describe CTA techniques and to instruct others in conducting CTA, as well as feedback we have received from those who have used the software, will be presented.
CRT text VS. VHF voice: Effects of Communication Modality in Single-Pilot Cockpits
Authors: Stokes Alan F. , Downs Joshua
Published: January 2012

Communications datalink, the transmission of messages as screen-displayed text between cockpits and ground stations, appears to offer both advantages and disadvantages compared to conventional VHF voice communications. The study reported here examines both the communication and performance of integrated communications datalink in single pilot instrument flight operations. Sixteen pilots flew two cross-country instrument flights in an AST complex-aircraft flight simulator with a moving map, traffic, and datalinked message display. In the conventional voice condition experimenters played the role of ATC controllers speaking over the radio. In the datalinked condition, controllers operated a computerized ‘ground station’, sending and receiving text messages on screen. Pilot communications, control and performance data were monitored for each phase of flight, as well as the interaction of pilot expertise and workload. The results suggest that communications datalink may widen the performance gap between experienced and inexperienced aviators, and that delayed responses are such that operational difficulties could occur, not least in busy airspace.
Interactive Voice Response (IVR) Systems as Automatic Speech Recognition (ASR) Comes of Age
Authors: Gardner-Bonneau Daryle , Delogu Cristina , Green Chuck , Volaitis Lydia , Lindeman Martha , Laux Lila
Published: January 2012

While interactive voice response (IVR) systems were rapidly making their way into the workplace, speech scientists were working hard to improve the performance of automatic speech recognition (ASR) systems to foster their acceptance among potential customers. In the last five years, great strides have been made in this regard, and the commercial use ASR is on the rise. The purpose of this panel is to explore the impact that ASR is (or is not) having on the design of IVR systems that were envisioned originally to operate solely via touch-tone input.
Banner Blindness: The Irony of Attention Grabbing on the World Wide Web
Authors: Benway Jan Panero
Published: January 2012

Web designers attempt to draw attention to important links by making them distinctive. However, when users are asked to find specific items, they often overlook these distinctive banners. The irony of “banner blindness” is that the user who really wants to find the information the designer has highlighted is not likely to do so. In the experiments reported here, banner blindness is reproduced under controlled conditions. Banners located higher on the page and therefore further from the other page links were missed more often than banners located lower on the page and closer to the other links. Banners were missed more often when located on pages containing links to categories than when located on pages with links to specific items. Users saw banners hardly at all when clicking a banner was not required to accomplish a task.
Evaluation of an Electroencephalographic-Based Control Device
Authors: Jones Keith S. , Middendorf Matthew S. , Calhoun Gloria , McMillan Grant
Published: January 2012

Electroencephalographic (EEG)-based control devices are one of several emerging technologies that will provide operators with a variety of new hands-free control options. In general, EEG-based control translates brain electrical activity into a control signal. The system evaluated in this study uses the steady-state visual evoked response for system control. The luminance of selectable items on a computer display was modulated at different frequencies. The operator's choice between these items was identified by detecting which frequency pattern was dominant in the visual evoked brain activity. One objective of this study was to characterize the performance of this human-machine system. In addition, two candidate control frequencies were evaluated. The results are encouraging. Participants were able to use this form of EEG-based control and performance was stable. Participants averaged over 90 percent correct selections. Future development will focus on increasing the speed and accuracy with which this novel hands-free controller can be utilized.
Spatially-Enhanced Auditory Cues and Computer Performance on a Simulated Monitoring Task
Authors: Murray La Tondra A.
Published: January 2012

This research examines the selection of nonspeech sounds for use in a computer-based application and furthermore assesses the performance of users engaged in a simulated manufacturing task. An empirical study was conducted to evaluate the utility of spatially-enhanced (three-dimensional) auditory cues in the computer interface. The seventy-two participants in this experiment interacted with a simulated interface using one of two spatially-enhanced sound groups (pure and hybrid) as selected from previous studies. Participants used the mouse to interact with the interface simulation and received alert information in the form of auditory cues, textual cues, or both. Performance for the simulated interface was measured in terms of: skill acquisition (learning), perceived workload, task omissions, incorrect responses, and task response time. The results show that spatially-enhanced nonspeech auditory cues can reduce perceived workload and shorten response times.
Towards an Empirically Determined Scale of Trust in Computerized Systems: Distinguishing Concepts and Types of Trust
Authors: Jian Jiun-Yin , Bisantz Ann M. , Drury Colin G.
Published: January 2012

One component in the successful use of automated, computerized systems is how much people trust these systems to perform effectively. In order to understand the relationship between trust in computerized systems and the use of those systems, we need to be able to measure that trust. Although questionnaires regarding trust have been used in prior studies, these questionnaires were not based on empirically generated scales and did not differentiate between concepts of trust and distrust, or between three potentially different types of trust: trust as a generic concept, human-human trust, and human-machine trust. A two-phased experimental study of trust concepts was performed, in order to understand similarities and differences in the concepts of trust and distrust, and between the different types of trust. Results indicated that trust and distrust can be considered opposites, rather than being comprised of different concepts. Additionally, concepts of trust were similar across the three types of trust.
Adding Interactivity to Paper Prototypes
Authors: Uceta Fernando A. , Dixon Max A. , Resnick Marc L.
Published: January 2012

This paper describes the design, implementation and evaluation of an interactive sketching technique for usability testing that utilizes only existing technologies and methods. The basic shortcoming of traditional paper based sketching is its lack of interactivity. This inability is overcome by digitizing the sketch and importing the resulting image(s) into PowerPoint™. PowerPoints™ powerful presentation features allow introduction of interactivity to the paper prototype without the need for special software or training. This is accomplished by hyperlinking various areas of the screen to simulate dynamic behaviors.
Frame of Reference and Navigation Through Document Visualizations: Flying Through Information Space
Authors: Vincow Michelle A. , Wickens Christopher D.
Published: January 2012

An experiment was conducted on navigation through three-dimensional visualizations of document databases. Subjects navigated through a 1000-document information space in which documents near each other were likely to be about a similar topic and keywords displayed in the space indicated the topic of nearby documents.

The influence of frame of reference and use of a map on document search and spatial judgment tasks was investigated. The frame of reference distinction compared a more egocentric (inside-out, immersed) perspective and a more exocentric (outside-in, bird's eye) perspective.

Performance was best with the exocentric display, with the egocentric display a close second. Use of a map hindered rather than supported performance. Results revealed tool/strategy choice as an important mediator of the influence of frame of reference, with non-optimal tool choices observed. Spatial ability correlated with performance. Results are accounted for in terms of mediating influences.
Warning Labels and Accident Data
Authors: Arndt S. R. , Ayres T. J. , McCarthy R. L. , Schmidt R. A. , Wood C. T. , Young D. E.
Published: January 2012

Accident data can be examined to assess the effectiveness of warning labels. In three separate analyses - involving vehicle handling, safety belt usage, and young children in bunk beds - we did not find any evidence that targeted accident or injury rates decreased with the introduction of new warning labels. Together with previous studies, these results show that it is difficult to demonstrate actual safety benefits for on-product warning labels.
Evaluation of time Delays in Firework Fuses: User Expectations of Product Feedback and Performance
Authors: Aurelio David N. , Mastoras Ellen A.
Published: January 2012

Injuries can occur with fireworks if they explode before users are a safe distance away, or when users approach a firework that they incorrectly assume is a dud. In this study, we investigated the amount of elapsed time before users start to approach an unexploded firework. We had 30 test participants light four fireworks. After lighting each one, the participants indicated: 1) when they thought the firework would explode, and 2) when they first thought the firework was a dud. Participants were asked to walk toward the firework when they assumed it was a dud and pick it up.

Our data showed that 95% of users would start to walk toward a firework after 9 seconds had elapsed. Based on the test results, the Consumer Product Safety Commission published a final rule in the Federal Register amending the U.S. fuse burn time regulation to allow fuses to burn for 3 to 9 seconds before exploding, as opposed to the 3 to 6 seconds required in the original regulations.
Consumer Product Warnings: Effects of Injury Statistics on Recall and Subjective Evaluations
Authors: Conzola Vincent C. , Wogalter Michael S.
Published: January 2012

Research has shown that explicitly worded warnings are judged to be more effective than similar warnings lacking explicitness. One possible way of increasing warning explicitness is to include injury outcome statistics in the warning statement. The heuristic processing model of persuasion would postulate that the impact of persuasive messages, like warnings, is influenced by heuristic cues such as the number and length of arguments and the presence of statistics. This research investigated the effect of embedding injury outcome statistics in the safety instructions for electric power tools. Warning statement recall and various rating judgments were measured. Results showed that the presence of statistics led to greater recall and higher ratings of warning importance, vividness, and explicitness. Implications for the design of consumer product warnings are discussed.
Optimal Sequence in Product Design
Authors: Helander Martin G. , Lin Li
Published: January 2012

This paper introduces Axiomatic Design (AD) for top-down design of ergonomics systems. The Independence Axiom was used to demonstrate how design activity can be structured to simplify the design process. Functional Requirements (FR) are first specified at a high level of abstraction and corresponding high level Design Parameters (DP) are generated. Then lower level Functional requirements are generated, and corresponding lower level Design Parameters. To avoid iterative improvements of design, one should strive for a decoupled design. This means that for each Functional Requirement there should ideally be only one Design Parameter - and this design parameter should satisfy only one functional requirement. Two case studies were used to illustrate the AD procedure.
Product Manual Safety Warnings: The Effects of Ordering
Authors: Vigilante William J. , Wogalter Michael S.
Published: January 2012

This study examined whether the ordering or sequencing of hazard warnings in product manuals affects users' acquisition of safety information. Participants were given one of five manuals that differed only in the warning sequencing. Warnings were ordered according to importance, obviousness, nonobviousness, the manufacturer's (original) ordering, or no warnings were present. Participants examined the manual for three minutes or had unlimited time. Later, participants were tested on their knowledge of warning-related material. Analysis showed that males and females produced different patterns of results. For males, the manual with the least obvious hazards first was best; for females, the manual with the most obvious hazards first was best. It is suggested that these results may be at partially due to product familiarity. The results indicate that the ordering of warnings can influence the amount of warning information that people acquire and that the best ordering might depend on such factors as the demographics or familiarity of the users.
Learning, or Not Learning, Through Multimedia
Authors: Eberts Ray , Cheng Kai-Chun
Published: January 2012

With the increasing availability of multimedia software and advanced computers at moderate prices, multimedia lessons are now entering the classroom. Many of the research ideas from human factors and cognitive psychology from the past two decades can now be implemented for teaching mainstream classes. This paper discusses experiences in developing a multimedia statistics course for engineering students that was taught totally on-line through the Internet with no live lectures. Lessons were devised so that students were shown computer-generated animation and could use interactive computer graphics to develop accurate mental models of the material, spatial representations of abstract concepts, and the ability to run mental simulations of the statistical processes. Student performance was assessed with homework assignments and paper-and-pencil tests similar to that done in past semesters. Students had a difficult time adjusting from a passive education role to a more active role. When assessing student performance in these traditional ways, improvements in performance were not found. When the Internet class was changed, however, to integrate the animated lessons with the assessment, performance improvements were found. Ideas are discussed for ways to transition students to take a more active role in learning and to re-examine classroom assessment techniques to more accurately determine the long-term effects of multimedia learning.
Evidence for Applying Ergonomic Principles to the Design of new Facilities
Authors: James Tamara , Ward Deborah A. , Farmer Sarah R.
Published: January 2012

This application involves the design of two new facilities at a major medical center. Both facilities were built at approximately the same time and both house people performing similar functions. The design group for one facility (A) enlisted the help of an ergonomist and the design group for the other facility (B) chose not to involve the ergonomist. After one year of occupancy, numerous employees in Facility B have requested ergonomic evaluations to help rid them of neck, back, shoulder, and wrist discomfort or pain. Only one employee in Facility A has asked for an evaluation or complained of musculoskeletal pain. These observations indicate the importance of involving an ergonomist in the design of new facilities.
How Do People Attribute Blame for Burns Sustained from Hot Coffee? The Role of Causal Attributions
Authors: Kalsher Michael J. , Phoenix Gregory M. , Wogalter Michael S. , Braun Curt C.
Published: January 2012

Safety researchers have begun to systematically examine how people assign blame for injuries sustained during the use of or exposure to consumer products. In this study we examine people's attributions in the context of product-use scenarios loosely based on the now famous incident in which a woman was scalded by hot coffee from McDonald's. Each scenario described a situation in which a person (driver or passenger) was burned when they spilled hot coffee on themselves while going to work. Supplementary information intended to be either positive or detrimental to McDonald's was either present or absent from the scenario. In general, participants allocated more responsibility to the consumer than to McDonald's. Depicting the consumer as the driver or passenger had no effect on participants' allocations. As expected, adding information that is detrimental to McDonald's shifted blame away from the consumer and toward McDonald's. Adding positive information had no corresponding effect. The implications of these results for consumers, legal professionals, and researchers are discussed.
The Effects of Perceived Morality and Facial Attractiveness on Allocations of Responsibility for Consumer Product Safety
Authors: McQuilkin Meredith L.
Published: January 2012

This study investigated the effects of perceived morality and facial attractiveness on allocations of responsibility in a civil litigation context. Confronted with uncertainty, jurors may focus less on the factual evidence presented and more on peripheral cues. It is hypothesized that jurors will attribute more responsibility to a bad individual compared to a good person, and unattractive consumers will be allocated more responsibility for an accident than their attractive counterparts. Results indicate perceived morality significantly influenced responsibility allocations. Bad people were given more responsibility than good people. Although unattractive consumers were given more responsibility than attractive consumers, the difference was not statistically significant. Finally, allocations to the consumer and manufacturer differed depending upon the product involved in the scenario, indicating that responsibility allocations to consumers is related to the type of product. Implications for civil litigation include the awareness that jurors' decisions are influenced by the type of product as well as subjective information about the consumer.
Effects of Warning Quality and Expert Testimony on Allocation of Responsibility for Consumer Product Accidents
Authors: Wogalter Michael S. , Brantley Kimberly A. , Laughery Kenneth R. , Lovvoll David R.
Published: January 2012

The purpose of this experiment was to examine the effects of warning quality and human factors expert testimony on decision making in consumer product injury cases. Participants read summaries of consumer product accidents, where a no, poor or good warning was present. In two conditions, human factors (HF) expert testimony was included, giving an opinion on the quality of the product warnings. Participants allocated percentages of responsibility to the manufacturer, retailer, and consumer, as if they were jury members assigned to the cases. Results showed differences in allocations of responsibility among conditions. Manufacturers were allocated more responsibility when there was no warning on the product or when a poor warning was present and a HF expert testified that a better warning could have been used. Allocations did not differ between poor and good warning conditions, possibly because participants viewing poor warnings lacked knowledge of the way a good warning would look. The results have implications for warning design, the use of HF expert witnesses, and jury decision making.
On the Description and Definition of Human Factors/Ergonomics
Authors: Wogalter Michael S. , Hancock Peter A. , Dempsey Patrick G.
Published: January 2012

This work examines the terms most frequently used to describe our field, which has variously been named Ergonomics, Human Factors, Human Factors Engineering, and Engineering Psychology. A large number of definitions were collected, including those assembled in an earlier technical report by Licht, Polzella, and Boff (1990). First, the definitions were stripped of connector words. Second, the prefix root terms that had the same meaning were combined and third, the words were tabulated and sorted to reveal the content terms most frequently employed. These data may be used to develop core, concise definitions or longer more expository descriptions of the field. The list of terms could also be used as a starting point for the development of definitions oriented for different target audiences (e.g., lay persons vs. other engineering/science experts) as a method of disseminating information concerning what we do.
Multivariate Methods in Engineering Anthropometry
Authors: Robinette Kathleen M.
Published: January 2012

Engineers and scientists have known for at least 45 years that univariate descriptive statistics, particularly percentiles, are inappropriate for use in designs that involve more than one dimension. Yet, the non-existent 5th percentile woman, and 95th percentile man are commonly referred to in the literature today. Arguments against using percentiles are numerous and compelling. It has been demonstrated that: 1) they will not ensure the accommodation of the desired population, 2) they are not additive so they will result in strangely proportioned models, and 3) they result in designs that waste materials. The source of the problem is the fact that they are univariate (one-dimensional) statistics applied to multivariate (many dimensional) situations. The primary argument for using percentiles has been that there were no alternatives. In this symposium we seek to remedy that. The speakers in this symposium will describe, compare, contrast and demonstrate some of the multivariate alternatives they have been developing and using. It is hoped that this will lead the way for other engineers and scientists in the field.
Chernobyl- Then, Now, and Where to Go from Here Symposium Abstract
Authors: Parsons Stuart O. , Meshkati Najmedin
Published: January 2012

This Symposium describes the current work being performed on the Shelter (Sarcophagus) and a number of Human Factors/Ergonomic activities which should be conducted at the Chernobyl Nuclear Power Plant #4 in the Ukraine. The initial cause of the accident is discussed as well as the necessity of including Ergonomics and a Safety Culture in the process of designing and operating complex technical facilities.
Time/Motion Considerations Redirect Humanitarian Demining Effort
Authors: Levy David
Published: January 2012

The search for buried landmines is currently a tedious and dangerous process, performed by hand to ensure the high degree of reliability required for reputable land recovery. An experimental class at MIT spent one semester working to develop new tools to increase the rate of manual landmine removal. By redefining the problem statement to address the results of a time/motion analysis, rather than directly addressing the landmine problem itself, the class conceived three new tools that use existing technologies in novel ways to increase the rate of the location and neutralization of hidden anti-personnel mines.
Deminer Decision Making: Criteria and Models
Authors: Sheridan Thomas B.
Published: January 2012

This paper discusses the application of signal detection theory to improving the efficiency and safety of humanitarian demining. Following an introductory description of the current compelling world-wide needs for improved demining technology, an analytical model is proposed. The model, based on conventional ideal observer or signal detection theory, assumes that one or set of detection instruments yield varying degrees of evidence of a mine at a given location. Given relative costs for missed detections and for false alarms, plus some probability estimates, the model specifies that degree of evidence at which the given location should “ideally” be treated as a live mine and efforts made to remove it or destroy it in place. It is suggested that this normative model can be implemented in a computer chip as a decision aid and be attached to any detection device. This would then assist the user in deciding when to treat a signal as indicative of an actual mine (risking that time will be wasted digging up some metal or plastic that is not a mine), and when to assume that the signal is not a mine (risking that it is in fact a mine which may subsequently be set off and cause injury or death).
Workload and Vigilance
Authors: Warm Joel S. , Dember William N. , Hancock Peter A.
Published: January 2012

A series of studies is described using the NASA-TLX to measure the perceived mental workload of vigilance tasks. Contrary to prior belief, these studies indicate that such tasks are not understimulating. Instead, the cost of mental operations in vigilance is substantial, with mental demand and frustration tending to be the primary contributors to workload. These findings support a resource model of vigilance suggested by Davies and Parasuraman (1982) and lead to the suggestion that the mental demand imposed by vigilance tasks should not be underestimated in the design of human-machine systems.
Applications of Individual-Differences: Assessment of Enviromental Influences
Authors: Bittner Alvah C.
Published: January 2012

Enhancing assessments of environmental-effects, particularly through the capturing and use of individual-differences information, has been of continuing interest over the last two decades. Applications of individual-differences information during the phases of environmental research are reviewed with illustrations from recent research studies (re: workplace exposures to Styrene, Perchloroethylene, and Hg0). Utility of individual-differences information is illustrated during: (1) early phases of research when concern is on understanding past research, (2) middle phases when focus is on selecting research methodology, and (3) the final phases when attention is turned to understanding and generalization of findings. It is concluded that: Assessments of environmental influences can be made more powerful, cost-efficient and meaningful by taking advantage of individual-differences information throughout the environmental research process.
Effects of Individual Differences in Propensity for Feedback in the Training of AB Initio Pilots
Authors: Koonce Jefferson M.
Published: January 2012

One hundred and fifty persons answered a questionnaire measuring self-esteem, propensity for feedback, self-efficacy, and certain demographic information. Subsequently, the students completed the Basic Flight Instruction Tutoring System (BFITS), a series of fully-automated criterion-referenced lessons designed to teach a person how to fly an airplane. BFITS provided feedback whenever student performance on monitored variables approached the limits of acceptable performance. After BFITS the students entered the traditional flight training program. Flight time prior to the first solo flight, landings before first solo, and total time to the private pilot certificate were obtained. Individual needs for feedback were significant factors of performance in the BFITS training and its transfer to the aircraft. Because of the interaction between individual propensity for feedback and training performance an individually adaptive feedback methodology is proposed.
Need for Cognition: An Individual Differences Approach to Understanding Warning Effectiveness
Authors: Conzola Vincent C. , Klein Katherine W.
Published: January 2012

Research has shown that trait individual differences in need for cognition influence the evaluation of persuasive messages. Product warning instructions can be considered a form of persuasive message because a goal of warnings is to change attitudes and alter behavior. This research investigated the relationship between need for cognition scores and rating and recall measures of warning quality and effectiveness. Product warning instructions were presented with and without injury outcome statistics, which may act as a heuristic cue in the persuasion process. Results showed that individuals higher in need for cognition recalled more warnings that contained statistics and judged all types of warnings as more important. The potential for individual differences to help explain warning effectiveness is discussed.
Identification of Stable Asymptotic Performance on Computer-Based Cognitive Tests
Authors: Hwang Byeong-Cheol , Schlegel Robert E. , Shehab Randa L.
Published: January 2012

Examining whether human cognitive performance is affected by environmental conditions requires stable performance measures prior to stressor exposure. This study evaluated the stability and reliability of six computer-based cognitive performance tasks. A Microsoft Excel Visual Basic for Applications (VBA) macro program, the Stability and Reliability Analysis System (SRAS), was developed to evaluate performance of the cognitive tests using three approaches for identifying stability: Graphical Analysis, Learning Curve Fitting, and Statistical Analysis. The results of the comparative evaluation indicated that the SRAS macro program was effective in determining differential stability for the various tasks and measures. Across all tasks, the use of a compound graphical analysis approach was better than a single graph method in terms of providing a more reliable estimation of task stability. Learning curves were fit to each performance measure. For most tasks, the best-fit models were power and logarithmic models. The statistical analysis methods provided conservative estimates of task stability.
Relationships between Clinical Scales on Severity of Symptoms and Electrodiagnostic Measures on Abnormality of Nerve Conduction in Carpal Tunnel Syndrome
Authors: You Heecheon
Published: January 2012

This study examined the severity of carpal tunnel syndrome symptoms in relation to nerve conduction measures of the median nerve. The symptom scales include (1) numbness, (2) tingling, (3) nocturnal symptoms, (4) pain, (5) weakness, and (6) clumsiness; the nerve conduction measures are (1) peak amplitude and (2) peak latency of the sensory action potential, (3) conduction velocity of the sensory nerve fibers, (4) peak amplitude and (5) onset latency of the motor action potential. The symptom severity and nerve conduction impairment were evaluated for 34 affected hands of 24 patients (6 males and 18 females) by using a questionnaire developed by Levine et al. and an electromyographic instrument, respectively. Significant relationships identified among the clinical scales resulted in a dichotomous symptom classification scheme with a criterion of the relatedness to nerve damage: primary and secondary symptoms. Correlation analysis on the symptom and electrodiagnostic measures showed both the severity scales for the primary and all the symptoms had higher correlations with the extent of the nerve injury than that for the secondary symptoms. These results demonstrated a biological significance of the clinical scales, which can be used in evaluating the outcome of treatments and developing a model for exposure-severity relationship.
Evaluation of Glove Liners with Objective, Subjective and Performance Measures
Authors: Chen S. C. , Tarawneh I. , Goodwin B. , Bishu R. R.
Published: January 2012

The objective of this study was to evaluate a number of inner glove liners used to protect the skin from latex proteins and chemical skin sensitizer found in gloves. A battery of performance tests were used for evaluating the inner gloves. Besides these, objective measurements such as skin temperature, skin conductance, and skin moisture content were measured. A series of subjective discomfort/comfort measures were also taken. Seventeen health care providers participated in this experiment where four liner conditions were evaluated at two temperatures. Some of the measures were recorded before and after the tests, while some other measures were recorded every fifteen minutes. Thus each subject participated in eight trials (4 liners X 2 temperatures). The tests were of two hours duration. Sweat, pegboard test, and discomfort measures were the best discriminators of liners, while the other subjective and objective measures were not.
Carpal Tunnel Syndrome Effects on Grip Force Coordination
Authors: Lowe Brian D. , Freivalds Andris
Published: January 2012

This study investigated the effects of carpal tunnel syndrome (CTS) on the coordination between grip force on and the force applied with a hand tool. A simulated tool device was developed to measure pinch grip force exerted on the tool and the force applied with the tool to a workpiece. Two measures of grip force coordination efficiency were calculated for seven subjects with diagnoses of carpal tunnel syndrome and seven controls. The dependent measures reflected subjects' abilities to (1) modulate grip force in parallel with the tool application force and (2) minimize the ratio of grip force to application force when dynamically applying forces with the tool. The parallel modulation of grip force with application force was 12% lower (p < 0.05) and the ratio of grip force to application force was 54% higher (p < 0.05) for the CTS group than for the controls. These results suggest that individuals with carpal tunnel syndrome lose some ability to efficiently coordinate grip force with tool application force.
Reliability Evaluation of the BIFMA Chair Measurement Device
Authors: Beaton Robert J.
Published: January 2012

This paper reports an evaluation of the reliability of the Business and Institutional Furniture Manufacturers Association's (BIFMA) chair measurement device (CMD) for assessing design specifications. Eight participants were trained to use the CMD to measure three typical office chairs. The variations in measurements obtained across participants, across chairs, and across the various chair design specifications were examined statistically. The standard deviations and confidence intervals for the measurements were used to evaluate inter-evaluator reliability (consistency across the different evaluators) and intra-evaluator reliability (consistency within an evaluator). The observed measurement errors were relatively small, indicating that CMD measurements can be made reliable across evaluators, as well as repeatedly by evaluators.
Effects of Computer Keyboard Setup Parameters and User's Anthropometric Characteristics on Wrist Deviation and Typing Efficiency
Authors: Marklin Richard W. , Simoneau Guy G. , Hoffman David
Published: January 2012

Two questions that computer keyboard operators face when using keyboards that can be separated into halves (split keyboards) are at what angle should the keyboard halves be opened and at what distance should the keyboard halves be placed apart. The objective of this study was to investigate the effects of the opening angle and separation distance between halves of a split keyboard on wrist radial/ulnar deviation and typing efficiency. Eleven experienced typists participated in this study and typed on a split keyboard configured in the following four arrangements.

1. The keyboard halves were setup the same way as a conventional keyboard. 2. The keyboard halves were contiguous but angled, based on the user's anthropometry, to maintain a theoretical neutral posture of the user's wrists in the radial/ulnar plane. 3. The keyboard halves were separated at a fixed distance of 20 cm, and the halves were angled to maintain a theoretical neutral posture of the user's wrists in the radial/ulnar plane. 4. The keyboard halves were separated at a distance equal to the user's shoulder width, and the halves were parallel to each other, resulting in a theoretical neutral posture of the user's wrists in the radial/ulnar plane.

The findings from testing these four keyboard configurations are the following:

1. The mean ulnar deviations from the alternative configurations of the split keyboard (configurations 2, 3, and 4 above) ranged from 7.0 to 8.4 for the left wrist and 2.7 to 5 deg. for the right wrist. There were no significant differences in ulnar deviations among the three alternative configurations. 2. The three alternative configurations resulted in ulnar deviation of both wrists that were significantly less than ulnar deviation from typing on the conventional setup (configuration 1 above). The mean ulnar deviations from the conventional setup were 18.9 deg. for the left wrist and 14.2 deg. for the right wrist. 3. There were no significant differences in typing speed and accuracy between the alternative and conventional configurations.
Assessing Low Back Stress in the Construction Industry Using the Continuous Assessment of Back Stress (CABS) Method
Authors: Mirka Gary A. , Kelaher Daniel P. , Nay D. Todd , Lawrence Brad M.
Published: January 2012

The construction industry has long been identified as a high risk industry for low back injuries due to the significant amount of manual materials handling and awkward trunk postures associated with many of its jobs. The variable nature of the tasks performed by construction workers expose these workers to risk factors for both acute and cumulative trauma injuries. The aim of this research project was to develop a modeling system that made use of existing assessment tools and probabilistic representations of low back stress. The results of this analysis are distributions of biomechanical stress that provide an appreciation for both the acute and cumulative trauma risks posed by these jobs.
Back Lift versus Leg Lift: A Dynamic Lifting Strategy Index
Authors: Zhang Xudong , Nussbaum Maury A. , Chaffin Don B.
Published: January 2012

This paper presents an index that quantitatively characterizes different dynamic postural strategies employed during sagittal plane lifting. The dynamic lifting strategy is analyzed in the velocity domain as a strategy of partitioning postural changes between the torso and leg segments. The index consists of two parameters, assigned to two leg segments, which quantify their contributions relative to the torso. Parameter values, ranging from 0.1 to 10, are estimated through a simple enumeration search. The use of this index is illustrated by applying it to 24 lifting movements performed by six subjects using either a back-lift or a leg-lift strategy. Results suggest that a lifting strategy, in terms of whether the leg or the back is the prime mover, can be well characterized by this simple two-parameter index. It not only differentiates the two distinct general postural strategies, but also discerns non-distinct intermediate ones by quantifying the involvement of each segment in a lifting movement.