bluuebunny/crossref_metadata_2025 huggingface dataset:
Douwe Draaisma. Why Life Speeds Up as You Get Older: How Memory Shapes Our Past. Cambridge, UK: Cambridge University Press, 2004.
Authors: Fortin Claudette
Published: January 2007

Ce livre traite de la mémoire autobiographique, c'est-à-dire de cette capacité d'emmagasiner et de récupérer l'information concernant notre expérience personnelle. Les thèmes abordés sont variés et vont de l'amnésie infantile jusqu'à ce phénomène souvent rapporté de rappel instantané de l'ensemble de la vie lorsque la mort est proche, en passant par différents sujets reliés aux expériences de vie tels que la mémoire des odeurs ou l'effet d'expériences traumatiques sur la mémorisation. On y trouve également de nombreuses références historiques reliées à l'étude de la mémoire. Plusieurs anecdotes et détails historiques sont rapportés dans un style narratif très vivant qui rend la lecture de ce texte particulièrement agréable et accessible à un auditoire non spécialisé. Ce livre captivera toute personne qui s'intéresse à la mémoire et à la recherche dans ce domaine.
Robert B. Hudson (Ed.). The New Politics of Old Age Policy. Baltimore, MD: Johns Hopkins University Pres, 2005.
Authors: Klassen Thomas R.
Published: January 2007

Le vieillissement de la population fait en sorte que les politiques concernant les personnes âgées attirent de plus en plus l'attention des gouvernements. Aux États-Unis, les deux principaux programmes pour les personnes âgées sont le programme d'assurance-vieillesse du volet sécurité sociale et le programme Medicare. The New Politics of Old Age Policy examine les enjeux liées ces programmes aux nouvelles conditions démographiques. Le thème du livre porte sur le degré de responsabilité de l'État plutôt que celles des individus en ce qui a trait au soutien des personnes âgées. En général, le livre est une introduction intéressante à la politique de sécurité du revenu aux États-unis. Toutefois, ses nombreuses répétitions, le traitement superficiel des sujets et son manque de cohérence en limite quelque peu la portée.
Health Status of Older Immigrants to Canada
Authors: Newbold K. Bruce , Filice John K.
Published: January 2007

Using the 2000/2001 Canadian Community Health Survey (CCHS), this paper examines the health status of the older (aged 55+) immigrant population relative to that of non-immigrants in order to identify areas where their health statuses diverge. First, we compare the health status of older immigrants (foreign-born) aged 55 and over in Canada to the Canadian-born in terms of age and gender using multiple measures of health status including self-assessed health. Second, we identify the factors associated with health status using the determinants of health framework. In both cases, the key questions are whether differences in health status exist and whether they are explained primarily by socio-economic, socio-demographic, or lifestyle factors that may point to problems with the Canadian health care system. Findings indicate that there is a relative comparability in the health status of older immigrants, even after controlling for age.
C. Claassen. Whistling Women: A Study of the Lives of Older Lesbians. Binghamton, NY: Haworth Press, 2005.
Authors: Stone Sharon Dale
Published: January 2007

En plus de présenter une fascinante ethnographie d'un sous-groupe de femmes américaines encore relativement peu connu, Whistling Women révise la prémisse selon laquelle toutes les personnes âgées sont d'orientation hétérosexuelle. S'appuyant sur des entrevues menées auprès de 44 lesbiennes, l'ouvrage présente les récits de vie de ces répondantes et examine leur expérience de la vieillesse. Globalement, ce livre présentera de l'intérêt pour les lecteurs intéressés à la question de l'influence du passé sur le présent ou sur les possibilités existantes pour les lesbiennes vieillissantes. Il manque toutefois à l'ouvrage une appréciation plus raffinée de ces questions d'un point de vue gérontologique.
A Literature Review of Randomized Controlled Trials of the Organization of Care at the End of Life
Authors: Thomas Roger E. , Wilson Donna , Sheps Sam
Published: January 2007

We searched nine electronic databases for randomized controlled trials (RCTs) about care at the end of life and found 23 RCTs. We assessed their quality using the criteria of the Cochrane Collaboration. The RCTs researched three themes: (a) the effect of providing palliative care through dedicated community teams on quality of life, on the management of symptoms, on satisfaction with care, on the duration of the palliative period, and on place of death; (b) the effects of specific palliative care interventions—advanced planning of care for the end of life, patient-held records, providing quality-of-life data to patients and physicians, grief education for relatives, palliative care education for nurses, and palliative care for patients with dementia; and (c) the costs of palliative compared to conventional care. We identify difficulties in conducting research on palliative care and solutions and discuss future possible research themes.
Pacific Islands Trade, Labor, and Security in an Era of Globalization
Authors: Firth Stewart
Published: January 2007

Globalization is having its most transformative effects in the Paciï¬c in three areas of economic and political life: trade, labor, and security. The global move from protection to free trade has reached the Paciï¬c and will have its greatest Â­initial impact on Fiji's sugar and garment industries, both of which face major restructuring and possibly extinction. Within ten years, the Paciï¬c Plan might also create economic integration within the entire Paciï¬c Islands Forum area, though the free movement of labor from the Islands into Australia and New ZeaÂ­land seems unlikely. Thanks in large part to the war in Iraq, Fiji has now joined Sämoa and Tonga as a remittance economy, but Papua New Guinea, Solomon Islands, and Vanuatu have little access to remittance income. Globalization in Solomon Islands has taken the form of unregulated investment in tropical logging, which has contributed to corrupting the political system. The consequence is regional intervention led by Australia, which is also attempting to shore up Papua New Guinea, where the government's priorities are inï¬uenced by its heavy dependence on foreign investors in resource projects. Globalization will probably widen inequalities throughout the Paciï¬c, and some countries will beneï¬t more than others. Cultural, historical, and demographic circumstances at the receiving end of globalization in the Island states of the Paciï¬c play determining roles in whether the process has positive or negative consequences.
Nemesis, Speaking, and Tauhi Vaha'a: Interdisciplinarity and the Truth of "Mental Illness" in Vava'u, Tonga
Authors: Poltorak Michael
Published: January 2007

The people of Vava'u, Tonga, manage to deal with most incidences of "mental illness" without resorting to institutionalization or overt stigmatization. The terms used to describe unusual behavior, though pejorative in the eyes of psychiatrist Dr Mapa Puloka, are contestable and negotiable. Through the creative use of a multiplicity of explanations, people have inï¬uence over the potential stigma to suffering relatives. People's sensitivity to attributions of "mental illness" is born of Vavauan use of language to tauhi vaha'a (evoke and intensify relatedness). This socially constitutive use of language contrasts with the referential language in much of the social science and medical literature that informs mental health policy. Revealing its origin in the experience of vä (relatedness) is key to creating an interdisciplinary space to discuss the late presentation of Tongans to mental health services in Tonga and New Zealand. This paper answers the widely recognized need for more qualitative, epistemologically sensitive, and interdisciplinary work on Tongan experience of mental illness through focusing on the particular case of an eccentric in Vava'u known as 'Ahiohio. As this man shares remarkable similarities with Manu (Epeli Hau'ofa's subversive mouthpiece of anti-absolutism), the responses to and theories of 'Ahiohio's behavior enable discussion on the contrast and effects of Vavauan and, more broadly, medical and positivist ideas of truth.
Beeckman, Descartes and the Force of Motion
Authors: Arthur Richard
Published: January 2007

In this reassessment of Descartes' debt to his mentor Isaac Beeckman, I argue that they share the same basic conception of motion: the force of a body's motion—understood as the force of persisting in that motion, shorn of any connotations of internal cause—is conserved through God's direct action, is proportional to the speed and magnitude of the body, and is gained or lost only through collisions. I contend that this constitutes a fully coherent ontology of motion, original with Beeckman and consistent with his atomism, which, notwithstanding Descartes' own profoundly original contributions to the theory of motion, is basic to all Descartes' further work in natural philosophy.
Concurrence or Divergence? Reconciling Descartes's Physics with his Metaphysics
Authors: Hattab Helen
Published: January 2007

This paper interprets Descartes's use of the Scholastic doctrine of divine concurrence in light of contemporaneous sources, and argues against two prevailing occasionalist interpretations. On the first occasionalist reading God's concurrence or cooperation with natural causes is always mediate (i.e., concurrence reduces to God's continual recreation of substances). The second reading restricts God's immediate concurrence to his co-action with minds. This paper shows that Descartes's metaphysical commitments do not necessitate either form of occasionalism, and that he is more plausibly and charitably read as appropriating elements of Scholastic views on concurrence to bridge the gap between his metaphysics and physics.
Newton and the Reality of Force
Authors: Janiak Andrew
Published: January 2007

Newton's critics argued that his treatment of gravity in the Principia saddles him with a substantial dilemma. If he insists that gravity is a real force, he must invoke action at a distance because of his explicit failure to characterize the mechanism underlying gravity. To avoid distant action, however, he must admit that gravity is not a real force, and that he has therefore failed to discover the actual cause of the phenomena associated with it. A reinterpretation of Newton's distinction between the "mathematical" and the "physical" treatment of force indicates how he can reject each horn of this dilemma.
The Eleatic Descartes
Authors: Lennon Thomas M
Published: January 2007

Given Descartes's conception of extension, space and body, there are deep problems about how there can be any real motion. The argument here is that in fact Descartes takes motion to be only phenomenal. The paper sets out the problems generated by taking motion to be real, the solution to them found in the Cartesian texts, and an explanation of those texts in which Descartes appears on the contrary to regard motion as real.
A Dialogue with Descartes: Newton's Ontology of True and Immutable Natures
Authors: McGuire J. E
Published: January 2007

This article is concerned with Newton's appropriation of Descartes' ontology of true and immutable natures in developing his theory of infinitely extended space. It contends that unless the part played by the Platonic distinction between "being a nature" and "having a nature" in Newton's thinking is properly appreciated the foundation of his doctrine of space in relation to God will not be fully understood. It also contends that Newton's Platonism is consistent with his empiricism once the mediating role is made clear that the geometry of moving loci play in grounding his intuitions concerning infinite natures.
The Evolution of Henry More's Theory of Divine Absolute Space
Authors: Reid Jasper William
Published: January 2007

This paper charts the gradual development of a theory of real space, underlying the created world and constituted by the extension of God Himself, in the writings of the Cambridge Platonist, Henry More. It identifies two impediments to More's embracing such a theory in the earlier part of his career, namely his initial commitment to the principles that (a) space was not real and (b) God was not extended, and it shows how he finally came to renounce these principles in order to devise the theory so closely associated with him.
General Hawkins's War: The Future of the Horse in the U.S. Cavalry
Authors: Bielakowski Alexander M
Published: January 2007

During the interwar period, while some officers supported mechanization, others, who could accurately be termed "traditionalists", supported the horse. One of the most prominent of these "traditionalists" was Brigadier General Hamilton S. Hawkins. Hawkins contended that mechanized vehicles would never be capable or numerous enough to completely eliminate the use of horse cavalry. Even as mechanized forces dominated the battlefield during World War II, Hawkins continued to write about the need for horse cavalry. Faced with overwhelming evidence in favor of mechanized vehicles, Hawkins ultimately demonstrated that his advocacy of the horse was a matter of faith and not of empirical evidence.
A History of Effects-Based Air Operations
Authors: Meilinger Phillip S.
Published: January 2007

Effects-Based Operations focus on results achieved from using military operations—the output. Too often, military commanders and their staffs concentrate on the means—the inputs—sterile metrics like body counts, bomb tonnage, or the number of sorties flown. U.S. airmen have always recognized the inherent logic and desirability of concentrating on effects, and their doctrine going into World War II emphasized this focus. Unfortunately, the intelligence apparatus necessary to analyze a complex enemy economic system did not then exist. Since then, new technologies and new analytical tools—which came into their own during the Persian Gulf War of 1991—have made this decades-old concept a reality.
"Our equivalent of guerrilla warfare": Walt Rostow and the Bombing of North Vietnam, 1961-1968
Authors: Milne David
Published: January 2007

This article examines the contribution that Walt Rostow made to the shaping of U.S. military strategy during the second Indochina War. It links Rostow's work as an economic historian with the advice that he dispensed in the field of strategic bombing. In 1964, Rostow explained to Secretary of State Dean Rusk that "Ho [Chi Minh] has an industrial complex to protect: he is no longer a guerrilla fighter with nothing to lose." Rostow's economic determinism led him to advocate the bombing of North Vietnam more forcefully than any of his civilian colleagues.
Scapegoat Arm: Twentieth-Century Cavalry in Anglophone Historiography
Authors: Phillips Gervase
Published: January 2007

The cavalry has not been treated kindly by military historians. Portrayed as an anachronism on the twentieth-century battlefield, the arm became a convenient scapegoat for failures in war and the slow pace of modernisation in peacetime. This article traces the debate over cavalry over the course of the last hundred years, drawing both on contemporary sources and later historical analysis. It is suggested that a reassessment of the capabilities of early twentieth-century soldiers and an interest in the military history of eastern Europe has led, in turn, to a more positive interpretation of the cavalry's role in modern warfare.
The What and Who of Information Literacy and Critical Thinking in Higher Education
Authors: Albitz Rebecca S
Published: January 2007

This review, in examining both the library and education literatures, explores two challenges currently facing many higher education faculty, librarians, and administrators: how one defines both information literacy and critical thinking skills, and who should be responsible for teaching either or both of these concepts.
Assessing Library Skills: A First Step to Information Literacy
Authors: Burkhardt Joanna M
Published: January 2007

As part of the University of Rhode Island Libraries' "Comprehensive Plan for Information Literacy," a three-credit class in the skills and concepts of information literacy was first offered in the fall of 1999. More than 1,000 undergraduate students have taken the class since that time. A pre-test was given at the beginning of each semester, followed up by a post-test at the end. The pre- and post-test results were analyzed to determine: (1) whether students improved their test scores over the course of the semester, (2) which concepts and skills students mastered, and (3) where the course might need revision and/or improvement. Analysis showed that skills were acquired and/or improved overall.
Library Faculty Publishing and Intellectual Property Issues: A Survey of Attitudes and Awareness
Authors: Carter Howard , Snyder Carolyn A , Imre Andrea
Published: January 2007

Researchers from Southern Illinois University Carbondale (SIUC) surveyed faculty members from 10 academic research libraries to learn about scholarly publishing activities, attitudes, and policies. Areas of special interest included the effect of publishers' intellectual property policies and institutional promotion and tenure processes on library faculty publishing decisions. The library faculty members were also asked about their experience in negotiating for additional rights from publishers and their experience in self-archiving their research. The researchers wanted to determine if there were any correlation between a library faculty member's rank and tenure status and the number of peer-reviewed articles published in refereed journals.
User Preferences in Reference Services: Virtual Reference and Academic Libraries
Authors: Cummings Joel , Cummings Lara , Frederiksen Linda
Published: January 2007

This study examines the use of chat in an academic library's user population and where virtual reference services might fit within the spectrum of public services offered by academic libraries. Using questionnaires, this research demonstrates that many within the academic community are open to the idea of chat-based reference or using chat for some loosely defined "research purposes," but this openness does not necessarily result in high levels of use. The primary purpose of this study was to determine whether the lack of virtual reference use could, in part, be explained by students' preference for competing methods and technologies for obtaining reference assistance. This study demonstrates a pattern that suggests chat-based reference does not compete well with other methods of providing reference service.
Information Literacy and Technology: An Examination of Some Issues
Authors: Grafstein Ann
Published: January 2007

The literature on information literacy often assumes that there is an inherent link between the need for information literacy and what is commonly referred to as the information explosion. This assumed link is reflected in programs of information literacy instruction offered by academic libraries. This article argues that the basic concepts of information literacy predate and are largely independent of the new information environment. It contends further that an emphasis in information literacy instruction on the specific challenges posed by the Internet and related information technologies may lead to an insufficient emphasis on other more basic and enduring components of information literacy.
Salary Compression: A Time-Series Ratio Analysis of ARL Position Classifications
Authors: Seaman Scott
Published: January 2007

Although salary compression has previously been identified in such professional schools as engineering, business, and computer science, there is now evidence of salary compression among Association of Research Libraries members. Using salary data from the ARL Annual Salary Survey, this study analyzes average annual salaries from 1994â1995 through 2004â2005. It compares changes in salary ratios between entry-, mid-, and senior-level librarians for evidence of salary compression during this 10-year period for 16 of the 20 formally defined ARL position classifications. Evidence is found for salary compression among the position classifications, but, with certain exceptions, the phenomenon of compression has become less severe among ARL librarians over the 10 years surveyed.
Measures to Shorten Publication Lags for Journals in China
Authors: Wang Fengnian
Published: January 2007

Because of the lengthy time taken for authors to revise and experts to evaluate, most periodicals in China suffer from publication lag. In the intense competition of the periodical publishing industry, publication lag has become one of the key factors in evaluating the quality of periodicals, as well as the academic value of articles. This article discusses ways to shorten the time from submission to publication, such as using electronic technologies and improving communication between authors and editors.
Active Trunk Stiffness During Voluntary Isometric Flexion and Extension Exertions
Authors: Lee Patrick J. , Granata Kevin P. , Moorhouse Kevin M.
Published: January 2007

Objective: Compare muscle activity and trunk stiffness during isometric trunk flexion and extension exertions. Background: Elastic stiffness of the torso musculature is considered the primary stabilizing mechanism of the spine. Therefore, stiffness of the trunk during voluntary exertions provides insight into the stabilizing control of pushing and pulling tasks. Methods: Twelve participants maintained an upright posture against external flexion and extension loads applied to the trunk. Trunk stiffness, damping, and mass were determined from the dynamic relation between pseudorandom force disturbances and subsequent small-amplitude trunk movements recorded during the voluntary exertions. Muscle activity was recorded from rectus abdominus, external oblique, lumbar paraspinal, and internal oblique muscle groups. Results: Normalized electromyographic activity indicated greater antagonistic muscle recruitment during flexion exertions than during extension. Trunk stiffness was significantly greater during flexion exertions than during extension exertions despite similar levels of applied force. Trunk stiffness increased with exertion effort. Conclusion: Theoretical and empirical analyses reveal that greater antagonistic cocontraction is required to maintain spinal stability during trunk flexion exertions than during extension exertions. Measured differences in active trunk stiffness were attributed to antagonistic activity during flexion exertions with possible contributions from spinal kinematics and muscle lines of action. Application: When compared with trunk extension exertions, trunk flexion exertions such as pushing tasks require unique neuromuscular control that is not simply explained by differences in exertion direction. Biomechanical analyses of flexion tasks must consider the stabilizing muscle recruitment patterns when evaluating spinal compression and shear loads.
Adaptability of Training in Simulated Process Control: Knowledge- Versus Rule-Based Guidance Under Task Changes and Environmental Stress
Authors: Hockey G. Robert J. , Sauer Jürgen , Wastell David G.
Published: January 2007

Objective: The study examined the adaptability of different types of process control training across changes in task and environmental stress. Background: The literature on training leads us to expect greater flexibility for system-based training, as opposed to procedure-based training. However, the stress literature suggests that knowledge-based strategies (making use of executive control) may be more vulnerable under stress conditions. Method: Two groups were given 6 hr of training on the Cabin Air Management System (CAMS), a complex, multilevel, PC-based process control task, emphasizing either system knowledge or use of procedures. They were then required to carry out the task for 3 hr (with noise during the middle 1 hr) across a range of both familiar and unfamiliar fault scenarios. Results: For the primary control task, the system-trained group performed better, especially for less familiar and complex faults. However, for lower priority tasks requiring executive control, procedure-trained operators performed better and were less impaired by noise. Conclusion: System training was more effective for managing unexpected task events, whereas procedural training was better under noise. The results are interpreted in terms of the rationale for instructing operators in the range of strategies required for effective process skills in complex work environments. Application: Training methodologies for safety critical applications should aim to develop skill in the use of both procedural and system knowledge strategies. Operators should be trained in the most effective deployment of these strategies during unfamiliar task events and environmental stress and given stress exposure training.
Seeing Size and Feeling Weight: The Size-Weight Illusion in Natural and Virtual Reality
Authors: Heineken Edgar , Schulte Frank P.
Published: January 2007

Objective: We experimentally tested the degree that the size-weight illusion depends on perceptual conditions allowing the observer to assume that both the visual and the kinesthetic stimuli of a weight seen and lifted emanate from the same object. We expected that the degree of the illusion depended on the “realism” provided by different kinds of virtual reality (VR) used when the weights are seen in virtual reality and at the same time lifted in natural reality. Background: Welch and Warren (1980) reported that an intermodal influence can be expected only if perceptual information of different modalities is compellingly related to only one object. Method: Objects of different sizes and weights were presented to 50 participants in natural reality or in four virtual realities: two immersive head-mounted display VRs (with or without head tracking) and two nonimmersive desktop VRs (with or without screening from input of the natural environment using a visor). The objects' heaviness was scaled using the magnitude estimation method. Results: Data show that the degree of the illusion is largest in immersive and lowest in nonimmersive virtual realities. Conclusion: The higher the degree of the illusion is, the more compelling the situation is perceived and the more the observed data are in correspondence with the data predicted for the illusion in natural reality. This shows that the kind of mediating technology used strongly influences the presence experienced. Application: The size-weight illusion's sensitivity to conditions that affect the sense of presence makes it a promising objective presence measure.
Designing for Flexible Interaction Between Humans and Automation: Delegation Interfaces for Supervisory Control
Authors: Miller Christopher A. , Parasuraman Raja
Published: January 2007

Objective: To develop a method enabling human-like, flexible supervisory control via delegation to automation. Background: Real-time supervisory relationships with automation are rarely as flexible as human task delegation to other humans. Flexibility in human-adaptable automation can provide important benefits, including improved situation awareness, more accurate automation usage, more balanced mental workload, increased user acceptance, and improved overall performance. Method: We review problems with static and adaptive (as opposed to “adaptable”) automation; contrast these approaches with human-human task delegation, which can mitigate many of the problems; and revise the concept of a “level of automation” as a pattern of task-based roles and authorizations. We argue that delegation requires a shared hierarchical task model between supervisor and subordinates, used to delegate tasks at various levels, and offer instruction on performing them. A prototype implementation called Playbook® is described. Results: On the basis of these analyses, we propose methods for supporting human-machine delegation interactions that parallel human-human delegation in important respects. We develop an architecture for machine-based delegation systems based on the metaphor of a sports team's “playbook.” Finally, we describe a prototype implementation of this architecture, with an accompanying user interface and usage scenario, for mission planning for uninhabited air vehicles. Conclusion: Delegation offers a viable method for flexible, multilevel human-automation interaction to enhance system performance while maintaining user workload at a manageable level. Application: Most applications of adaptive automation (aviation, air traffic control, robotics, process control, etc.) are potential avenues for the adaptable, delegation approach we advocate. We present an extended example for uninhabited air vehicle mission planning.
Age Differences in Identifying Words in Synthetic Speech
Authors: Roring Roy W. , Hines Franklin G. , Charness Neil
Published: January 2007

Objectives: We investigated whether context or different speech rates could improve older adult performance on identification of synthetically generated words. Background: Synthetic speech systems can potentially improve the daily functioning of older adults. However, research must determine whether older adults can effectively implement current text-to-speech technologies, which few studies have examined. Older adults' sensory and cognitive declines may cause difficulties in identifying words in synthetic speech. Methods: Ninety-six participants (young, middle-aged, and older adults) identified auditory monosyllabic words (half natural, half synthetic) presented in isolation or at the ends of sentences. Participants heard speech at either normal or slower rates. Results: We found an interaction of age, context, and voice type and that slower speech rates worsened performance for all groups. Contrasts revealed that context reduced age differences, though only for natural speech. Hearing acuity was highly correlated with age and fully accounts for the interaction. Conclusions: Context improves performance for everyone in natural speech. However, whereas context improves performance for synthetic speech, it does not differentially reduce the age impairment for older adults. Slower speed generally impairs everyone's performance compared with the normal rate. Applications: Systems using synthetic speech should avoid presenting words in isolation, and rich contextual support should be consistently adopted. Synthetic speech fidelity must be improved significantly before becoming truly useful for older adult populations.
Perception-Action Icons: An Interface Design Strategy for Intermediate Domains
Authors: Talcott Christopher P. , Bennett Kevin B. , Martinez Silas G. , Shattuck Lawrence G. , Stansifer Craig
Published: January 2007

Objective: A prototype interface was developed to support decision making during tactical operations; a laboratory experiment was conducted to evaluate the capability of this interface to support a critical activity (i.e., obtaining the status of friendly combat resources). Background: Effective interface design strategies have been developed for domains that have primarily law-driven (e.g., process control) or intent-driven (e.g., information retrieval) constraints. However, design strategies for intermediate domains in which both types of constraints are equally critical, such as military command and control, have not been explored as extensively. The principles of direct perception, direct manipulation, and perception-action loops were used to develop a hybrid interface design strategy (“perception-action icons”) that was incorporated into the prototype interface. Methods: A qualitative tactical simulation and an alternative interface (an experimental version of an existing U.S. Army interface) were developed. Participants used both interfaces to provide estimates of friendly combat resources for three different categories of information at three different echelon levels. Results: The results were unequivocal, indicating that the interface with perception-action icons produced significantly better performance. Conclusion: The perception-action icon design strategy was very effective in this experimental context. The potential for this design strategy to be useful for other intermediate domains is explored. Application: Actual or potential applications of this research include both specific interface design strategies for military command and control and general interface design principles for intermediate work domains.
Predicting Dual-Task Performance With the Multiple Resources Questionnaire (MRQ)
Authors: Boles David B. , Bursk Jonathan H. , Phillips Jeffrey B. , Perdelwitz Jason R.
Published: January 2007

Objective: The objective was to assess the validity of the Multiple Resources Questionnaire (MRQ) in predicting dual-task interference. Background: Subjective workload measures such as the Subjective Workload Assessment Technique (SWAT) and NASA Task Load Index are sensitive to single-task parameters and dual-task loads but have not attempted to measure workload in particular mental processes. An alternative is the MRQ. Method: In Experiment 1, participants completed simple laboratory tasks and the MRQ after each. Interference between tasks was then correlated to three different task similarity metrics: profile similarity, based on r2 between ratings; overlap similarity, based on summed minima; and overall demand, based on summed ratings. Experiment 2 used similar methods but more complex computer-based games. Results: In Experiment 1 the MRQ moderately predicted interference ( r = +.37), with no significant difference between metrics. In Experiment 2 the metric effect was significant, with overlap similarity excelling in predicting interference ( r = +.83). Mean ratings showed high diagnosticity in identifying specific mental processing bottlenecks. Conclusion: The MRQ shows considerable promise as a cognitive-process-sensitive workload measure. Application: Potential applications of the MRQ include the identification of dual-processing bottlenecks as well as process overloads in single tasks, preparatory to redesign in areas such as air traffic management, advanced flight displays, and medical imaging.
Effects of Imperfect Automation on Decision Making in a Simulated Command and Control Task
Authors: Rovira Ericka , McGarry Kathleen , Parasuraman Raja
Published: January 2007

Objective: Effects of four types of automation support and two levels of automation reliability were examined. The objective was to examine the differential impact of information and decision automation and to investigate the costs of automation unreliability. Background: Research has shown that imperfect automation can lead to differential effects of stages and levels of automation on human performance. Method: Eighteen participants performed a “sensor to shooter” targeting simulation of command and control. Dependent variables included accuracy and response time of target engagement decisions, secondary task performance, and subjective ratings of mental workload, trust, and self-confidence. Results: Compared with manual performance, reliable automation significantly reduced decision times. Unreliable automation led to greater cost in decision-making accuracy under the higher automation reliability condition for three different forms of decision automation relative to information automation. At low automation reliability, however, there was a cost in performance for both information and decision automation. Conclusion: The results are consistent with a model of human-automation interaction that requires evaluation of the different stages of information processing to which automation support can be applied. Application: If fully reliable decision automation cannot be guaranteed, designers should provide users with information automation support or other tools that allow for inspection and analysis of raw data.
Glove and Gender Effects on Muscular Fatigue Evaluated by Endurance and Maximal Voluntary Contraction Measures
Authors: Shih Yuh-Chuan
Published: January 2007

Objective: To investigate the effects of gender and gloves on hand fatigue, measured by the reduction in grip strength (ΔMVC), the shift in time needed to reach maximal voluntary contraction (MVC; ΔTMVC), and the maximal endurance time (MET). Background: Information about the effect of gloves on muscle fatigue seems to be less plentiful than that on hand strength, dexterity, sensation, and so on. Method: Ten male and 10 female volunteers served as participants. A task of sustained gripping until exhaustion was used as the designated fatigue protocol. Three gloved conditions were evaluated: bare-handed and single (Cotton 1) and double (Cotton 2) cotton gloves. Results: After completion of the fatigue protocol, a greater reduction in grip strength was found for men than for women in both magnitude and percentage. Male ΔTMVC was significantly greater; that is, there was more delay in time needed to reach the MVC for men than for women when the fatigue protocol was completed. MET was longer for men than for women. During gloved conditions, except for the ΔMVC, glove use did not change any of the other responses. Specifically, the gloved effect on ΔMVC depended upon gender. Conclusion: Men had a greater reduction in grip strength and took longer to reach the MVC than did women after the fatigue protocol. Except for decreasing the ΔMVC, whether or not gloves were worn did not change any of the other responses. Application: These data are useful for glove design, manufacture, and selection.
Developing Operator Capacity Estimates for Supervisory Control of Autonomous Vehicles
Authors: Cummings M.L. , Guerlain Stephanie
Published: January 2007

Objective: This study examined operators' capacity to successfully reallocate highly autonomous in-flight missiles to time-sensitive targets while performing secondary tasks of varying complexity. Background: Regardless of the level of autonomy for unmanned systems, humans will be necessarily involved in the mission planning, higher level operation, and contingency interventions, otherwise known as human supervisory control. As a result, more research is needed that addresses the impact of dynamic decision support systems that support rapid planning and replanning in time-pressured scenarios, particularly on operator workload. Method: A dual screen simulation that allows a single operator the ability to monitor and control 8, 12, or 16 missiles through high level replanning was tested on 42 U.S. Navy personnel. Results: The most significant finding was that when attempting to control 16 missiles, participants' performance on three separate objective performance metrics and their situation awareness were significantly degraded. Conclusion: These results mirror studies of air traffic control that demonstrate a similar decline in performance for controllers managing 17 aircraft as compared with those managing only 10 to 11 aircraft. Moreover, the results suggest that a 70% utilization (percentage busy time) score is a valid threshold for predicting significant performance decay and could be a generalizable metric that can aid in manning predictions. Application: This research is relevant to human supervisory control of networked military and commercial unmanned vehicles in the air, on the ground, and on and under the water.
Factors Affecting Task Management in Aviation
Authors: Iani Cristina , Wickens Christopher D.
Published: January 2007

Objective: We investigated the influence of ongoing task display “compellingness” on attention allocation patterns and assessed its interaction with interrupting task salience and importance. Background: There are some concerns that the compellingness of flight deck tunnel displays renders the task they support more resistant to interruptions, thus preventing the pilot from noticing cues signaling the need to divert attention to other tasks. Methods: Forty pilots flew three curved approaches in a high-fidelity simulation using a synthetic vision system (SVS) display. In addition to the primary task of flying, during the last approach they were required to select the approach path on the basis of environmental information concerning weather. The display layout supporting the primary flight task (tunnel vs. baseline display), the nature of the cue signaling the need to divert attention to the path selection task (visual vs. auditory-visual cue), and the cost of not performing the secondary task were manipulated to investigate their influence on task prioritization. Results: The modality and priority of the cue affected the frequency of the switch to the secondary task. Furthermore, pilots flying with a tunnel display were more likely to detect the change in the weather and were easily interrupted by the secondary task when priority was high. Conclusion: Our results suggest that some of the concerns regarding the negative consequences of the compelling nature of the tunnel display may not be as pronounced as thought. Applications: This study highlights the utility of the tunnel display in improving flight safety.
Guidelines for Wrist Posture Based on Carpal Tunnel Pressure Thresholds
Authors: Keir Peter J. , Bach Joel M. , Hudes Mark , Rempel David M.
Published: January 2007

Objective: To develop work guidelines for wrist posture based on carpal tunnel pressure. Background: Wrist posture is considered a risk factor for distal upper extremity musculoskeletal disorders, and sustained wrist deviation from neutral at work may be associated with carpal tunnel syndrome. However, the physiologic basis for wrist posture guidelines at work is limited. Methods: The relationship of wrist posture to carpal tunnel pressure was examined in 37 healthy participants. The participants slowly moved their wrists in extension-flexion and radioulnar deviation while wrist posture and carpal tunnel pressure were recorded. The wrist postures associated with pressures of 25 and 30 mmHg were identified for each motion and used to determine the 25th percentile wrist angles (the angles that protect 75% of the study population from reaching a pressure of 25 or 30 mmHg). Results: Using 30 mmHg, the 25th percentile angles were 32.7° (95% confidence interval [CI] = 27.2°—38.1°) for wrist extension, 48.6° (37.7°—59.4°) for flexion, 21.8° (14.7°—29.0°) for radial deviation, and 14.5° (9.6°—19.4°) for ulnar deviation. For 25 mmHg, the 25th percentile angles were 26.6° and 37.7° for extension and flexion, with radial and ulnar deviation being 17.8° and 12.1°, respectively. Conclusion: Further research can incorporate the independent contributions of pinch force and finger posture into this model. Application: The method presented can provide wrist posture guidelines for the design of tools and hand-intensive tasks.
Alerts for In-Vehicle Information Systems: Annoyance, Urgency, and Appropriateness
Authors: Marshall Dawn C. , Lee John D. , Austria P. Albert
Published: January 2007

Objective: This study assesses the influence of the auditory characteristics of alerts on perceived urgency and annoyance and whether these perceptions depend on the context in which the alert is received. Background: Alert parameters systematically affect perceived urgency, and mapping the urgency of a situation to the perceived urgency of an alert is a useful design consideration. Annoyance associated with environmental noise has been thoroughly studied, but little research has addressed whether alert parameters differentially affect annoyance and urgency. Method: Three 23 × 3 mixed within/between factorial experiments, with a total of 72 participants, investigated nine alert parameters in three driving contexts. These parameters were formant (similar to harmonic series), pulse duration, interpulse interval, alert onset and offset, burst duty cycle, alert duty cycle, interburst period, and sound type. Imagined collision warning, navigation alert, and E-mail notification scenarios defined the driving context. Results: All parameters influenced both perceived urgency and annoyance ( p < .05), with pulse duration, interpulse interval, alert duty cycle, and sound type influencing urgency substantially more than annoyance. There was strong relationship between perceived urgency and rated appropriateness for high-urgency driving scenarios and a strong relationship between annoyance and rated appropriateness for low-urgency driving scenarios. Conclusion: Sound parameters differentially affect annoyance and urgency. Also, urgency and annoyance differentially affect perceived appropriateness of warnings. Application: Annoyance may merit as much attention as urgency in the design of auditory warnings, particularly in systems that alert drivers to relatively low-urgency situations.
Localization of Virtual Objects in the Near Visual Field
Authors: Ellis Stephen R. , Menges Brian M.
Published: January 2007

We examined errors in the localization of nearby virtual objects presented via see-through helmet-mounted displays as a function of viewing conditions and scene content in four experiments using a total of 38 participants. Monocular, biocular, and stereoscopic presentation of the virtual objects, accommodation (required focus), participants′ age, and the position of physical surfaces were examined. Nearby physical surfaces were found to introduce localization errors that differ depending on the other experimental factors. These errors apparently arise from the occlusion of the physical background by the optically superimposed virtual objects, but they are modified by participants′ accommodative competence and specific viewing conditions. The apparent physical size and transparency of the virtual objects and physical surfaces, respectively, are influenced by their relative position when superimposed. The design implications of the findings are discussed in a concluding section. Head-mounted displays of virtual objects are currently being evaluated as aids for mechanical assembly and equipment maintenance. Other applications include telesurgery, surgical planning, telerobotics, and visualization aids for robotic programming.
Effects of Variation in System Responsiveness on User Performance in Virtual Environments
Authors: Watson Benjamin , Walker Neff , Ribarsky William , Spaulding Victoria
Published: January 2007

System responsiveness (SR) is defined as the elapsed time until a system responds to user control. SR fluctuates over time, so it must be described statistically with mean (MSR) and standard deviation (SDSR). In this paper, we examine SR in virtual environments (VEs), outlining its components and methods of experimental measurement and manipulation. Three studies of MSR and SDSR effects on performance of grasp and placement tasks are then presented. The studies used within-subjects designs with 11, 12, and 10 participants, respectively. Results showed that SDSR affected performance only if it was above 82 ms. Placement required more frequent visual feedback and was more sensitive to SR. We infer that VE designers need not tightly control SDSR and may wish to vary SR control based on required visual feedback frequency. These results may be used to improve the human-computer interface in a wide range of interactive graphical applications, including scientific visualization, training, mental health, and entertainment.