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Recent efforts to characterize the human microbiome and its relation to chronic diseases have led to a surge in statistical development for compositional data. We develop likelihood-based sufficient dimension reduction methods (SDR) to find linear combinations that contain all the information in the compositional data on an outcome variable, i.e., are sufficient for modeling and prediction of the outcome. We consider several models for the inverse regression of the compositional vector or transformations of it, as a function of outcome. They include normal, multinomial, and Poisson graphical models that allow for complex dependencies among observed counts. These methods yield efficient estimators of the reduction and can be applied to continuous or categorical outcomes. We incorporate variable selection into the estimation via penalties and address important invariance issues arising from the compositional nature of the data. We illustrate and compare our methods and some established methods for analyzing microbiome data in simulations and using data from the Human Microbiome Project. Displaying the data in the coordinate system of the SDR linear combinations allows visual inspection and facilitates comparisons across studies. [ABSTRACT FROM AUTHOR]

Objective: EDs have the potential ability to predict patient wait times and to display this to patients and other stakeholders. Little is known about whether consumers and stakeholders would want this information and how wait time predictions might be used. The aim of the present study was to gain perspectives from consumers and health services personnel regarding the concept of emergency wait time visibility. Methods: We conducted a qualitative interview and focus group study in 2019. Participants included emergency medicine patients, families, paramedics, well community members, and hospital/paramedic administrators from multiple EDs and organisations in Victoria, Australia. Transcripts were coded and themes presented. Results: One focus group and 103 semi‐structured interviews were conducted in 2019 including 32 patients, 22 carers/advocates and 21 paramedics in the ED; 20 health service administrators (paramedic and hospital) and 15 community members. Consumers and paramedics face physical and psychological difficulties when wait times are not visible. Consumers believe about a 2‐h wait is tolerable, beyond this most begin to consider alternative strategies for seeking care. Consumers want to see triage to doctor times; paramedics want door‐to‐off stretcher times (for all possible transport destinations); with 47 of 50 consumers and 30 of 31 paramedics potentially using this information. About 28 of 50 consumers would use times to inform facility or provider choice, another 19 of 50 want information once in the waiting room. During prolonged waits, 51 of 52 consumers would continue to seek care. Conclusions: Consumers and paramedics want wait time information visibility. They would use the information in a variety of ways, both pre‐hospital and while waiting for care. [ABSTRACT FROM AUTHOR]

Objective: The aim is to provide a high-level synthesis of human factors research that contributed to the development of detect-and-avoid display requirements for unmanned aircraft systems (UAS).Background: The integration of UAS into the U.S. National Airspace System is a priority under the Federal Aviation Administration's Modernization and Reform Act. For UAS to have routine access to the National Airspace System, UAS must have detect-and-avoid capabilities. One human factors challenge is to determine how to display information effectively to remote pilots for performing detect-and-avoid tasks.Method: A high-level review of research informing the display requirements for UAS detect-and-avoid is provided. In addition, description of the contributions of human factors researchers in the writing of the requirements is highlighted.Results: Findings from human-in-the-loop simulations are used to illustrate how evidence-based guidelines and requirements were established for the display of information to assist pilots in performing detect-and-avoid. Implications for human factors are discussed.Conclusion: Human factors researchers and engineers made many contributions to generate the data used to justify the detect-and-avoid display requirements. Human factors researchers must continue to be involved in the development of standards to ensure that requirements are evidence-based and take into account human operator performance and human factors principles and guidelines.Application: The research presented in this paper is relevant to the design of UAS, the writing of standards and requirements, and the work in human-systems integration. [ABSTRACT FROM AUTHOR]

Objective: To develop a multicenter, multistakeholder, prospective clinical registry of children and adolescents with migraine to support the collection of real‐world data of sufficient quality to support regulatory submissions and provide site‐based infrastructure support for future clinical trials. Background: As new migraine treatments come to market, pediatric efficacy and safety trials of these agents are needed. A clinical registry is an ideal regulatory strategy to provide both real‐world data and site infrastructure to execute these trials. Design: Multicenter, multistakeholder, prospective real‐world data clinical registry of children and adolescents, 4‐17 years of age, diagnosed with migraine with or without aura. Participants will be followed for up to 12 months at 3‐month intervals, with interval recording of clinical data at study sites and self‐reported data via mobile health application, as well as biobanking. We developed electronic case report forms that incorporated routinely collected clinical data with National Institute of Neurological Disorders and Stroke Headache Common Data Elements (Version 2.0). All data are captured in a 21 CFR Part 11 – compliant electronic data capture system – augmented by a real‐time, web‐based, and customizable data visualization platform. We engaged vendors to provide ancillary biobanking, patient data entry, and data visualization services. Results: We used an iterative and highly collaborative multistakeholder approach to design and implement a streamlined registry protocol with input from all participating US sites. At each design and implementation step, we received input from therapeutic area experts, the US Food and Drug Administration (FDA), the National Institutes of Health, patient and parent advocates, health technology partners, drug developers, and site‐based clinical investigators. The registry is governed by a multistakeholder steering committee with representation from sites, industry partners, patient advocates, and a member from the FDA (non‐voting with respect to steering committee matters). The multistakeholder and site‐driven approach to registry design and execution was highly efficient and resulted in the first patient enrolled within 6 months of concept development. Conclusions: By ensuring regulatory compliant implementation of the registry, we created both a source of real‐world data and a multisite platform for the conduct of future clinical trials that can be submitted to regulatory authorities to support inclusion of pediatric data in approved drug labeling. A highly collaborative approach with broad stakeholder engagement at all stages of the registry development was a key to our operational success. [ABSTRACT FROM AUTHOR]

Clinical trials are often designed to compare treatments on the basis of multiple outcomes. For the analysis of the treatment comparison from such a trial, in 1999, the Finkelstein-Schoenfeld test was proposed, which was a generalization of the Gehan-Wilcoxon test based on pairwise comparison of patients on a primary outcome when possible but otherwise on a secondary outcome. In 2012, Pocock and colleagues suggested an estimate based on this concept, the Win Ratio, which summarized the ratio of the number of patients who fared better versus worse on the experimental arm. However, in 2016, Oakes noted that the Win Ratio could be a function of the distribution of follow-up times of the trial. The aim of this paper is to propose an approach to representing the Win Ratio graphically in such a way that the effect of time on the estimate would be apparent. In addition, the methods are used to display the contribution of each endpoint to the composite. We apply the methods to clinical trials in cancer, cardiology, and neurology. Software is available named winRatioAnalysis in CRAN. [ABSTRACT FROM AUTHOR]

Objective: We evaluated three interface input methods for a simulated manned-unmanned teaming (MUM-T) supervisory control system designed for Air Mission Commanders (AMCs) in Black Hawk helicopters.Background: A key component of the U.S. Army's vision for unmanned aerial vehicles (UAVs) is to integrate UAVs into manned missions, called MUM-T (Department of Defense, 2010). One application of MUM-T is to provide the AMC of a team of Black Hawk helicopters control of multiple UAVs, offering advanced reconnaissance and real-time intelligence of flight routes and landing zones.Method: Participants supervised a (simulated) team of two helicopters and three UAVs while traveling toward a landing zone to deploy ground troops. Participants classified aerial photographs collected by UAVs, monitored instrument warnings, and responded to radio communications. We manipulated interface input modality (touch, voice, multimodal) and task load (number of photographs).Results: Compared with voice, touch and multimodal control resulted in better performance on all tasks and resulted in lower subjective workload and greater subjective situation awareness, ps < .05. Participants with higher spatial ability classified more aerial photographs ( r = .75) and exhibited shorter response times to instrument warnings ( r = -.58) than participants with lower spatial ability.Conclusion: Touchscreen and multimodal control were superior to voice control in a supervisory control task that involved monitoring visual displays and communicating on radio channels.Application: Although voice control is often considered a more natural and less physically demanding input method, caution is needed when designing visual displays for users sharing common communication channels. [ABSTRACT FROM AUTHOR]

Organisms exploit spatiotemporal regularities in the environment to optimize goal attainment. For example, in experimental conditions, repetition of a stimulus at the same position speeds up response time. A recent study reported that this spatial priming occurs even when the eyes move between trials, indicating that the target is encoded in spatiotopic coordinates (Attention, Perception & Psychophysics 78, (2016) 114-132). However, in that study, the relevant position of the repeated stimulus eliciting spatiotopic priming, was always at the screen center. Using a similar paradigm, we find that reaction times for screen-centered targets are markedly shorter than for retinally-equidistant target positions. When this center preference is taken into account, the alleged spatiotopic priming effects are dramatically reduced, though not totally eliminated. In a second experiment, we show that the preferred central stimulus position is encoded in allocentric coordinates (e.g. screen position) rather than in an egocentric frame of reference (e.g. straight ahead). The better performance at the screen center, irrespective of gaze direction or seating position, is likely to reflect an optimal choice for the allocation of spatial attention. [ABSTRACT FROM AUTHOR]

Objective: To compare the diagnostic accuracy of medical-grade and calibrated consumer-grade digital displays for the detection of subtle bone fissures.Methods: Three experienced radiologists assessed 96 digital radiographs, 40 without and 56 with subtle bone fissures, for the presence or absence of fissures in various bones using one consumer-grade and two medical-grade displays calibrated according to the DICOM-Grayscale Standard Display Function. The reference standard was consensus reading. Subjective image quality was also assessed by the three readers. Statistical analysis was performed using receiver operating characteristic analysis and by calculating the sensitivity, specificity, and Youden's J for each combination of reader and display. Cohen's unweighted kappa was calculated to assess inter-rater agreement. Subjective image quality was compared using the Wilcoxon signed-rank test.Results: No significant differences were found for the assessment of subjective image quality. Diagnostic performance was similar across all readers and displays, with Youden's J ranging from 0.443 to 0.661. The differences were influenced more by the reader than by the display used for the assessment.Conclusion: No significant differences were found between medical-grade and calibrated consumer-grade displays with regard to their diagnostic performance in assessing subtle bone fissures. Calibrated consumer-grade displays may be sufficient for most radiological examinations.Key Points: • Diagnostic performance of calibrated consumer-grade displays is comparable to medical-grade displays. • There is no significant difference with regard to subjective image quality. • Use of calibrated consumer-grade displays could cut display costs by 60-80%. [ABSTRACT FROM AUTHOR]

Background: Anaesthetists monitor auditory information about a patient's vital signs in an environment that can be noisy and while performing other cognitively demanding tasks. It can be difficult to identify oxygen saturation (SpO2) values using existing pulse oximeter auditory displays (sonifications).Methods: In a laboratory setting, we compared the ability of non-clinician participants to detect transitions into and out of an SpO2 target range using five different sonifications while they performed a secondary distractor arithmetic task in the presence of background noise. The control sonification was based on the auditory display of current pulse oximeters and comprised a variable pitch with an alarm. The four experimental conditions included an Alarm Only condition, a Variable pitch only condition, and two conditions using sonifications enhanced with additional sound dimensions. Accuracy to detect SpO2 target transitions was the primary outcome.Results: We found that participants using the two sonifications enhanced with the additional sound dimensions of tremolo and brightness were significantly more accurate (83 and 96%, respectively) at detecting transitions to and from a target SpO2 range than participants using a pitch only sonification plus alarms (57%) as implemented in current pulse oximeters.Conclusions: Enhanced sonifications are more informative than conventional sonification. The implication is that they might allow anaesthetists to judge better when desaturation decreases below, or returns to, a target range. [ABSTRACT FROM AUTHOR]

Background: Asymptomatic atrial fibrillation (AF) is increasingly common in the aging population and implicated in many ischemic strokes. Earlier identification of AF with appropriate anticoagulation may decrease stroke morbidity and mortality.Methods: We conducted a randomized controlled trial of AF screening using an AliveCor Kardia monitor attached to a WiFi-enabled iPod to obtain ECGs (iECGs) in ambulatory patients. Patients ≥65 years of age with a CHADS-VASc score ≥2 free from AF were randomized to the iECG arm or routine care (RC). iECG participants acquired iECGs twice weekly over 12 months (plus additional iECGs if symptomatic) onto a secure study server with overread by an automated AF detection algorithm and by a cardiac physiologist and/or consultant cardiologist. Time to diagnosis of AF was the primary outcome measure. The overall cost of the devices, ECG interpretation, and patient management were captured and used to generate the cost per AF diagnosis in iECG patients. Clinical events and patient attitudes/experience were also evaluated.Results: We studied 1001 patients (500 iECG, 501 RC) who were 72.6±5.4 years of age; 534 were female. Mean CHADS-VASc score was 3.0 (heart failure, 1.4%; hypertension, 54%; diabetes mellitus, 30%; prior stroke/transient ischemic attack, 6.5%; arterial disease, 15.9%; all CHADS-VASc risk factors were evenly distributed between groups). Nineteen patients in the iECG group were diagnosed with AF over the 12-month study period versus 5 in the RC arm (hazard ratio, 3.9; 95% confidence interval=1.4-10.4; P=0.007) at a cost per AF diagnosis of $10 780 (£8255). There was a similar number of stroke/transient ischemic attack/systemic embolic events (6 versus 10, iECG versus RC; hazard ratio=0.61; 95% confidence interval=0.22-1.69; P=0.34). The majority of iECG patients were satisfied with the device, finding it easy to use without restricting activities or causing anxiety.Conclusions: Screening with twice-weekly single-lead iECG with remote interpretation in ambulatory patients ≥65 years of age at increased risk of stroke is significantly more likely to identify incident AF than RC over a 12-month period. This approach is also highly acceptable to this group of patients, supporting further evaluation in an appropriately powered, event-driven clinical trial.Clinical Trial Registration: URL: https://www.isrctn.com. Unique identifier: ISRCTN10709813. [ABSTRACT FROM AUTHOR]

Background Five-megapixel (MP) displays are recommended as soft copy devices for digital mammogram. An 8-MP liquid crystal display (LCD) (two 4-MP displays within one display) might offer the advantage of being able to view biplane mammography more easily than the dual planes of 5-MP LCDs. Purpose To compare detectability of Breast Imaging Reporting and Data System (BI-RADS) category 3 or higher lesions and reading time on mammography between 5- MP and 8-MP LCDs. Material and Methods The mammograms of 240 breasts of 120 patients including 60 breasts with BI-RADS category 3 or higher lesions and 180 breasts with normal or category 2 lesions were enrolled. All bilateral mammograms were displayed on bifacial 5-MP LCDs or an 8-MP LCD (two 4-MP displays within one display). Six radiologists assessed 240 breasts on each display. The observations were analyzed using receiver operating characteristic (ROC) analysis. A jack-knife method was used for statistical analysis. We employed a paired t-test to determine whether any significant differences existed in the reading time between two different displays. A P value < 0.05 was considered significant. Results The mean areas under the ROC curve obtained using 5-MP and 8-MP LCDs were 0.925 and 0.915, respectively, and there was no significant difference ( P = 0.46). There was also no significant difference in the reading time between two types of displays (57.8 min. vs. 51.5 min, P = 0.39). Conclusion The detectability of BI-RADS category 3 or higher lesions and reading time using an 8-MP LCD were comparable to those using a 5-MP LCD. [ABSTRACT FROM AUTHOR]

Objectives: To assess (i) understanding, acceptability and preference for two graphical displays of the Mediterranean diet (MD); and (ii) feasibility of a brief MD intervention and cost of adherence to this diet among British older adults.Design: Two studies undertaken at the Human Nutrition Research Centre, Newcastle University are reported. In study-1, preference and understanding of the MD guidelines and two graphical displays, a plate and a pyramid, were evaluated in an educational group session (EGS). In study-2, we evaluated the feasibility of a three-week brief MD intervention with two levels of dietary advice: Group-1 (level 1) attended an EGS on the MD, and Group-2 (level 2) attended an EGS and received additional support. MD adherence using a 9-point score, and the cost of food intake during intervention, were assessed. RESULTS STUDY-1: No differences in preference for a MD plate or pyramid were observed. Both graphic displays were rated as acceptable and conveyed clearly these guidelines. STUDY-2: The intervention was rated as acceptable. No significant differences were observed between groups 1 and 2. Analysis of the combined sample showed significant increases from baseline in fish intake (P=0.01) and MD score (P=0.05). The cost of food intake during intervention was not significantly different from baseline.Conclusion: British older adults rated a MD as an acceptable model of healthy eating, and a plate and a pyramid as comprehensible graphic displays of these guidelines. A brief dietary intervention was also acceptable and revealed that greater adherence to the MD could be achieved without incurring significantly greater costs. [ABSTRACT FROM AUTHOR]

Background: Graphs are often used in medical communication, both in clinical practice and health management. They can help the processing of quantitative information but may also contribute to drawing wrong conclusions. The aim of the survey is to study the graphical perception of the data at the management level and its possible effects, showing how some criteria of appraisal of a phenomenon are influenced by the graphical format. Methods: One hundred and five medical doctors and health direction professionals of hospitals in Naples, Rome, Siena and Turin were interviewed. Four different graphs or table related to the same hypothetical data on average hospital stay in the period January 2000 to September 2003 were shown to participants, and their impressions were recorded. Results: Less than one-fourth of the participants understood that the data set was the same for the different diagrams. The process of understanding is mostly correlated with being a director, having a degree in medicine and working in central–northern cities. The table seems easier for interpretation (98.1%), more suitable (84.8%), more used (92.4%) and more pleasant than other data presentation. On the other hand radar format had worse results in all questions. Conclusions: The choice of a graphical format may influence the understanding of data. Further research is needed in order to sustain the improvement of medical and health professionals’ knowledge in the display data format. [ABSTRACT FROM PUBLISHER]

Objective: We provide a review and analysis of much of the published literature on binocular rivalry that is relevant to the design and use of head-worn displays (HWDs).Background: This review draws heavily from both the basic vision literature and applied HWD literature in order to help provide insight for minimizing the effects of binocular rivalry when HWDs are worn.Method: Included in this review are articles and books found cited in other works as well as articles and books obtained from an Internet search.Results: Issues discussed and summarized are (a) characteristics of binocular rivalry, (b) stimulus factors affecting rivalry, (c) cognitive variables affecting rivalry, and (d) tasks affected by rivalry.Conclusion: This paper offers a set of recommendations for minimizing the effects of binocular rivalry when HWDs are used as well as recommendations for future research.Application: Considerations of the basic vision literature on binocular rivalry will provide insight for future design solutions for HWDs. [ABSTRACT FROM AUTHOR]

Objective: Two experiments examined the detectability of multiple transient changes within a cluttered and dynamic display (a simulated sonar display).Background: Research suggests that there are severe limitations when multiple targets must be detected within close temporal proximity. The present research explored whether these limitations influence performance in a dynamic monitoring task.Method: Participants monitored a cluttered and dynamic display and reported the number of new objects that appeared (one to four objects). The time between onset events was varied. A blinking cue sometimes accompanied each new object, giving observers multiple opportunities to detect it.Results: A large decrease in performance was observed when participants were asked to detect multiple targets within a short period of time. Performance was worse than predicted based on the attention literature. Performance suffered when observers were asked to detect more than two or three targets. The blinking cue greatly attenuated this performance deficit, even for short-duration blinking cues (one blink).Conclusion: Operators can easily become overwhelmed when asked to respond to even a small number of events when these events occur close in time. Extending transient events in time improves performance, but some attentional limitations may be difficult or impossible to overcome.Application: These results have important implications for systems in which important events may occur within close temporal proximity (e.g., when a sonar operator is tasked with detecting threats in the battle space). Situations in which these limitations may or may not influence performance are discussed. [ABSTRACT FROM AUTHOR]

Objective: We evaluated the nauseogenic properties of commercial console video games (i.e., games that are sold to the public) when presented through a head-mounted display.Background: Anecdotal reports suggest that motion sickness may occur among players of contemporary commercial console video games.Methods: Participants played standard console video games using an Xbox game system. We varied the participants' posture (standing vs. sitting) and the game (two Xbox games). Participants played for up to 50 min and were asked to discontinue if they experienced any symptoms of motion sickness.Results: Sickness occurred in all conditions, but it was more common during standing. During seated play there were significant differences in head motion between sick and well participants before the onset of motion sickness.Conclusion: The results indicate that commercial console video game systems can induce motion sickness when presented via a head-mounted display and support the hypothesis that motion sickness is preceded by instability in the control of seated posture.Application: Potential applications of this research include changes in the design of console video games and recommendations for how such systems should be used. [ABSTRACT FROM AUTHOR]

Objective: Performance consequences related to integrating an imperfect alert within a complex task domain were examined in two experiments.Background: Cockpit displays of traffic information (CDTIs) are being designed for use in airplane cockpits as responsibility for safe separation becomes shared between pilots and controllers. Of interest in this work is how characteristics of the alarm system such as threshold, modality, and number of alert levels impact concurrent task (flight control) performance and response to potential conflicts.Methods: Student pilots performed a tracking task analogous to flight control while simultaneously monitoring for air traffic conflicts with the aid of a CDTI alert as the threshold, modality, and level of alert was varied.Results: As the alerting system became more prone to false alerts, pilot compliance decreased and concurrent performance improved. There was some evidence of auditory preemption with auditory alerts as the false alarm rate increased. Finally, there was no benefit to a three-level system over a two-level system.Conclusion: There is justification for increased false alarm rates, as miss-prone systems appear to be costly. The 4:1 false alarm to miss ratio employed here improved accuracy and concurrent task performance. More research needs to address the potential benefits of likelihood alerting.Application: The issues addressed in this research can be applied to any imperfect alerting system such as in aviation, driving, or air traffic control. It is crucial to understand the performance consequences of new technology and the efficacy of potential mitigating design features within the specific context desired. [ABSTRACT FROM AUTHOR]

Objective: Determine the effects of display viewing distance on both the visual and musculoskeletal systems while the text height is held constant across viewing distances.Background: The distance from the eyes to a computer display may affect visual and neck comfort. If the angular size of the characters remains the same, it is recommended that the display be placed at a farther viewing distance (e.g., 70-100 cm). However, in common usage, the character sizes are not adjusted based on viewing distance.Method: Participants under the age of 35 years (N = 24) performed visually demanding tasks using a computer display for 2 hr each at three viewing distances (mean: 52.4, 73.0, and 85.3 cm) while torso and head posture were tracked. At the end of each task, eye accommodation was measured and symptoms were recorded.Results: The near distance was associated with significantly less blurred vision, less dry or irritated eyes, less headache, and improved convergence recovery when compared with the middle and far distances. Participants moved their torsos and heads closer to the monitor at the far distance.Conclusion: If the computer screen character sizes are close to the limits of visual acuity, it is recommended that the computer monitor be positioned between the near (52 cm) and middle (73 cm) distance from the eyes.Application: The location of a computer display should take into account the size of the characters on the screen and the visual acuity of the user. [ABSTRACT FROM AUTHOR]

Objective: The aim of the present study was to determine if a wearable system based on a head-mounted display (HMD) causes users to alter their head position and adopt postures that place greater stress on the musculoskeletal system.Background: HMDs are common output devices used with wearable computers. HMDs provide the wearer with visual information by projecting computer-generated virtual images in front of the eyes. Deviations of neck posture from a neutral upright position increase the stresses on the musculoskeletal system of the head and neck.Method: Seven paramedics simulated the treatment of a patient under a normal condition and when using an HMD wearable computer system. During the simulations a posture analysis was performed using the Rapid Upper Limb Assessment method.Results: The postures adopted when wearing an HMD, as compared with a normal condition, scored significantly higher for the neck (z = 2.463, p < .05) and for overall body posture (left side of the body: z = 2.447, p < .05; right side of the body: z = 2.895, p < .05).Conclusion: Wearing an HMD can force the wearers to modify their neck posture. As such, the musculoskeletal system of the head and neck may be placed under increased levels of stress.Application: Potential users should be made aware that HMDs could dictate modifications in neck posture, which may have detrimental effects and may compound the weight effect of the HMD. [ABSTRACT FROM AUTHOR]

Background: Diagnostic assessment of myocardial perfusion impacts the management of patients with suspected coronary artery disease (CAD). Although various image displays are available for single photon emission computed tomography (SPECT) interpretation, the effects of display differences on SPECT interpretation remain undetermined.Methods and Results: We studied 183 patients undergoing SPECT, including 131 consecutive patients referred for angiography and 52 at low CAD risk. Studies were visually interpreted by use of color and gray images, with readers blinded to the results of the other display. In accordance with established criteria, a summed stress score (SSS) of 4 or greater was considered abnormal. The prevalence of abnormal SPECT findings was higher with gray images than with color images (54% vs 48%, P < .001) based on a uniform criterion (SSS > or =4). However, color images yielded equivalent sensitivity (79% vs 82%, P = .7) and improved specificity for global (50% vs 33%, P = .02) and vessel-specific CAD involving the right coronary artery (P < .01) and left anterior descending artery (P < .05). When the criterion for gray images was adjusted upward (SSS > or =5) to reflect increased mean defect severity (SSS of 5.1 vs 4.4, P = .01), gray and color images provided equivalent sensitivity and specificity for global and vessel-specific CAD.Conclusions: SPECT interpretation can vary according to image display as a result of differences in perfusion defect severity. Adjustment of abnormality criteria for gray images to reflect minor increases in defect severity provides equivalent diagnostic performance of gray and color displays for CAD assessment. [ABSTRACT FROM AUTHOR]

Objectives: To increase the chance for a cure, cancer must be detected as early as possible. This can be achieved with cytopathological diagnostic methods. For a further increase of the diagnostic accuracy of these methods we introduced the multimodal cell analysis, viz, cells on the slide have to be relocalized to enable successive analysis of identical cells in different stains. For practical reasons the relocalization step must be automated.Methods: For a fully automatic acquisition of successive cell images we use a passive autofocus that is adaptive to the material, i.e., to the cells, followed by a comparison of the scenes, i.e., the cell constellation, of two such obtained images from different stains. In case that no sub-scene match can be found the search is extended to the surrounding area. A set of 1556 scenes from seven specimens have been subject to our algorithm. The automatically relocalized and acquired images from a second stain have been manually compared to the images from a first stain.Results: An overall relocalization rate of 85.4% is achieved. 14.3% of the images could not be relocalized and are lost for the following diagnostic process, while the critical case of erroneously matched images was observed in only 0.3% of cases.Conclusions: We could show that it is possible to automatically acquire images of successive stains of identical cells on cytopathological specimens. The method presented achieves acceptable relocalization rates. Wrong image acquisitions are very rare and can mostly be ascribed to images with single cells, i.e., without scene information. [ABSTRACT FROM AUTHOR]

Objective: This experiment attempted to identify the features of air traffic geometry that would influence the difficulty and biases of pilots' conflict detection using a cockpit display of traffic information (CDTI).Background: There was previously no systematic study on effects of such features on conflict detection using the CDTI.Method: Twenty-four pilots viewed dynamic encounters between their own aircraft and an intruder aircraft on a simulated CDTI; difficulty was varied by the intruder aircraft's distance and time to closest point of approach (CPA), relative speed, miss distance at CPA, approach side, and conflict angle. Participants estimated the intruder's location at, and its time to, CPA. Effects on three estimation error measures were explored: intruder's miss distance at CPA, orientation at CPA, and time to CPA.Results: (a) Estimation errors increased with slower speeds, longer times to CPA, and longer distances to CPA and with longer miss distances at CPA; (b) the best performance occurred at a conflict angle of 90 degrees; (c) there was a bias to judge conflicts to be more risky than was actually the case; and (d) there was a "distance-over-speed" bias, such that two aircraft farther apart and converging rapidly were perceived as less risky than when they were closer to each other and converging at a slower rate, despite identical time to CPA.Conclusion: Pilots' conflict detection with CDTI was subject to various errors and biases, which has important safety implications.Application: The design of procedures, displays, and decision support tools for the free flight environment needs to take these human performance limitations into account. [ABSTRACT FROM AUTHOR]

Objective: An evaluation study was conducted to answer the question of which system properties of night vision enhancement systems (NVESs) provide a benefit for drivers without increasing their workload.Background: Different infrared sensor, image processing, and display technologies can be integrated into an NVES to support nighttime driving. Because each of these components has its specific strengths and weaknesses, careful testing is required to determine their best combination.Method: Six prototypical systems were assessed in two steps. First, a heuristic evaluation with experts from ergonomics, perception, and traffic psychology was conducted. It produced a broad overview of possible effects of system properties on driving. Based on these results, an experimental field study with 15 experienced drivers was performed. Criteria used to evaluate the development potential of the six prototypes were the usability dimensions of effectiveness, efficiency, and user satisfaction (International Organization for Standardization, 1998).Results: Results showed that the intelligibility of information, the easiness with which obstacles could be located in the environment, and the position of the display presenting the output of the system were of crucial importance for the usability of the NVES and its acceptance.Conclusion: All relevant requirements are met best by NVESs that are positioned at an unobtrusive location and are equipped with functions for the automatic identification of objects and for event-based warnings.Application: These design recommendations and the presented approach to evaluate the systems can be directly incorporated into the development process of future NVESs. [ABSTRACT FROM AUTHOR]

Objective: To evaluate which of three color coding methods (monochrome, maximally discriminable, and visual layering) used to code four types of control room display format (bars, tables, trend, mimic) was superior in two classes of task (search, compare). Background: It has recently been shown that color coding of visual layers, as used in cartography, may be used to color code any type of information display, but this has yet to be fully evaluated. Method: Twenty-four people took part in a 2 (task) x 3 (coding method) x 4 (format) wholly repeated measures design. The dependent variables assessed were target location reaction time, error rates, workload, and subjective feedback. Results: Overall, the visual layers coding method produced significantly faster reaction times than did the maximally discriminable and the monochrome methods for both the search and compare tasks. No significant difference in errors was observed between conditions for either task type. Significantly less perceived workload was experienced with the visual layers coding method, which was also rated more highly than the other coding methods on a 14-item visual display quality questionnaire. Conclusion: The visual layers coding method is superior to other color coding methods for control room displays when the method supports the user's task. Application: The visual layers color coding method has wide applicability to the design of all complex information displays utilizing color coding, from the most maplike (e.g., air traffic control) to the most abstract (e.g., abstracted ecological display). [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

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 work-load, 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. [ABSTRACT FROM AUTHOR]

Objectives: An experiment was conducted to assess the effects of distraction mitigation strategies on drivers' performance and productivity while engaged in an in-vehicle information system task.Background: Previous studies show that in-vehicle tasks undermine driver safety and there is a need to mitigate driver distraction.Method: An advising strategy that alerts drivers to potential dangers and a locking strategy that prevents the driver from continuing the distracting task were presented to 16 middle-aged and 12 older drivers in a driving simulator in two modes (auditory, visual) and two road conditions (curves, braking events).Results: Distraction was a problem for both age groups. Visual distractions were more detrimental than auditory ones for curve negotiation, as depicted by more erratic steering, F (6, 155) = 26.76, p < .05. Drivers did brake more abruptly under auditory distractions, but this effect was mitigated by both the advising, t (155) = 8.37, p < .05, and locking strategies, t (155) = 8.49, p < .05. The locking strategy also resulted in longer minimum time to collision for middle-aged drivers engaged in visual distractions, F (6, 138) = 2.43, p < .05.Conclusions: Adaptive interfaces can reduce abrupt braking on curve entries resulting from auditory distractions and can also improve the braking response for distracted drivers.Application: These strategies can be incorporated into existing in-vehicle systems, thus mitigating the effects of distraction and improving driver performance. [ABSTRACT FROM AUTHOR]

Objective: Two experiments examined the detectability of transient changes in cluttered and dynamic displays and optimal scan strategies for performance.Background: Research has demonstrated that onset changes are prioritized by the attention system and onsets are often used to signal important display changes. However, research has mostly used uncluttered, static displays and has largely ignored the role of scan strategy.Method: We had participants monitor a cluttered and dynamic display and respond when an object changed color or onset abruptly. Scan strategies were also evaluated. In another experiment participants were instructed to use particular strategies to detect changes.Results: Consistent with previous results, onset events were detected better than were color change events. Scan strategy accounted for a large proportion of variance in detection performance. Participants who made few eye movements performed best. Participants who actively scanned the display performed worst. When poor performers were instructed to make few eye movements, their performance matched that of the best performers.Conclusion: Onset alerts can be an effective means of signaling important events in complex displays. Additionally, scan strategy plays an important role in the detection of transient events.Application: These results have important implications for training operators to search for transient changes within dynamic and cluttered displays. [ABSTRACT FROM AUTHOR]

Rationale and Objectives: To compare two display technologies, cathode ray tube (CRT) and liquid crystal display (LCD), in terms of diagnostic accuracy for several common clinical tasks in digital mammography. Materials and Methods: Simulated masses and microcalcifications were inserted into normal digital mammograms to produce an image set of 400 images. Images were viewed on one CRT and one LCD medical-quality display device by five experienced breast-imaging radiologists who rated the images using a categorical rating paradigm. The observer data were analyzed to determine overall classification accuracy, overall lesion detection accuracy, and accuracy for four specific diagnostic tasks: detection of benign masses, malignant masses, and microcalcifications, and discrimination of benign and malignant masses. Results: Radiologists had similar overall classification accuracy (LCD: 0.83 +/- 0.01, CRT: 0.82 +/- 0.01) and lesion detection accuracy (LCD: 0.87 +/- 0.01, CRT: 0.85 +/- 0.01) on both displays. The difference in accuracy between LCD and CRT for the detection of benign masses, malignant masses, and microcalcifications, and discrimination of benign and malignant masses was -0.019 +/- 0.009, 0.020 +/- 0.008, 0.012 +/- 0.013, and 0.0094 +/- 0.011, respectively. Overall, the two displays did not exhibit any statistically significant difference (P > .05). Conclusion: This study explored the suitability of two different soft-copy displays for the viewing of mammographic images. It found that LCD and CRT displays offer similar clinical utility for mammographic tasks. [ABSTRACT FROM AUTHOR]

Objective: We provide a review and analysis of much of the published literature on visual perception issues that impact the design and use of head-mounted displays (HMDs).Background: Unlike the previous literature on HMDs, this review draws heavily from the basic vision literature in order to help provide insight for future design solutions for HMDs.Method: Included in this review are articles and books found cited in other works as well as articles and books obtained from an Internet search.Results: Issues discussed include the effect of brightness and contrast on depth of field, dark focus, dark vergence, and perceptual constancy; the effect of accommodation-vergence synergy on perceptual constancy, eyestrain, and discomfort; the relationship of field of view to the functioning of different visual pathways and the types of visual-motor tasks mediated by them; the relationship of binocular input to visual suppression; and the importance of head movements, head tracking, and display update lag.Conclusion: This paper offers a set of recommendations for the design and use of HMDs.Application: Consideration of the basic vision literature will provide insight for future design solutions for HMDs. [ABSTRACT FROM AUTHOR]

Objective: To conceptualize delivery of anesthesia as a control task, similar to control tasks in nonmedical domains, and to evaluate how presentation of new information and feedback affects task performance.Background: In anesthesia, integrated monitors that show intravenous drug and effect-site concentrations in a patient currently do not exist. However, using real-time displays of intravenous anesthetic concentrations and effects could significantly enhance intraoperative clinical performance. Pharmacological models are available to estimate past, present, and future drug concentrations in the brain and to predict the drug's physiological effects. A display that integrates pharmacological models and visualizes drug concentrations was developed and tested to see if this drug display significantly improved clinical performance.Method: Thirty-three anesthesiologists with different levels of expertise administered anesthesia to simulated patients in a high-fidelity patient simulator. The experimental group used a drug display that visualized drug concentrations in real time, whereas the control group administered drugs without this information.Results: Anesthesiologists using the drug display achieved better hemodynamic control of the simulated patient than did the control group. Similarly, the drug display enabled anesthesiologists to wake up and reanimate the patient faster.Conclusion: Visual feedback of drug concentrations leads to superior performance in the delivery of anesthesia. Drug delivery can be conceptualized within a control theoretical framework. Finally, the drug display has significant clinical potential to increase patient safety.Application: Clinical performance in delivering anesthesia depends on feedback. By providing this feedback, the drug display supports clinicians' ability to more precisely and safely administer anesthesia. [ABSTRACT FROM AUTHOR]

Background: Although telecommunication is increasing in popularity, poor-quality images sent through a narrowband network limit its use in the medical field.Methods: Kyushu University Hospital in Japan and four hospitals in Korea were linked via superfast broadband Internet connection. The digital video transfer system, which can transmit digital videos without loss of image quality, was used, and the bandwidth was 30 Mbps per line.Results: Of the 16 teleconferences conducted, 6 demonstrated real-time endoscopic surgery. In addition to the surgical images, preoperative diagnostic images, images of the operating room, and images of the staff in the conference room were transmitted to facilitate discussion. The network remained stable, and the sound delay was restricted to less than 0.3 s. In the other 10 teleconferences, recorded video images were used for discussion.Conclusions: The authors have established a high-quality, practical teleconference system that is economical and easy to use in clinical practice. This system shows promise for remote education beyond geographic borders. [ABSTRACT FROM AUTHOR]

Effects of font design and electronic display parameters upon text legibility were determined using a threshold size method. Participants' visual acuity (inverse of the minimum detection size, representing the threshold legibility for each condition) was measured using upper- and lowercase letters and lowercase words in combinations of 6 fonts, 3 font-smoothing modes, 4 font sizes, 10 pixel heights, and 4 stroke widths. Individual lowercase letters were 10% to 20% more legible than lowercase words (i.e., lowercase words must be 10%-20% larger to have the same threshold legibility). This letter superiority effect suggests that individual letters play a large role and word shape plays a smaller role, if any, in word identification at threshold. Pixel height, font, stroke width, and font smoothing had significant main effects on threshold legibility. Optimal legibility was attained at 9 pixels (10 points). Verdana and Arial were the most legible fonts; Times New Roman and Franklin were least legible. Subpixel rendering (ClearType) improved threshold legibility for some fonts and, in combination with Verdana, was the most legible condition. Increased stroke width (bold) improved threshold legibility but only at the thinnest width tested. Potential applications of this research include optimization of font design for legibility and readability. [ABSTRACT FROM AUTHOR]

We conducted four studies regarding the representation of probabilistic information. Experiments 1 through 3 compared performance on a simulated stock purchase task, in which information regarding stock profitability was probabilistic. Two variables were manipulated: display format for probabilistic information (blurred and colored icons, linguistic phrases, numeric expressions, and combinations) and specificity level (in which the number and size of discrete steps into which the probabilistic information was mapped differed). Results indicated few performance differences attributable to display format; however, performance did improve with greater specificity. Experiment 4, in which participants generated membership functions corresponding to three display formats, found a high degree of similarity in functions across formats and participants and a strong relationship between the shape of the membership function and the intended meaning of the representation. These results indicate that participants can successfully interpret nonnumeric representations of uncertainty and can use such representations in a manner similar to the way numeric expressions are used in a decision-making task. Actual or potential applications of this research include the use of graphical representations of uncertainty in systems such as command and control and situation displays. [ABSTRACT FROM AUTHOR]

Two experiments conducted in a high-fidelity flight simulator examined the effects of guidance symbology, display size, and geometric field of view (GFOV) within a synthetic vision system (SVS). In Experiment 1, 18 pilots flew highlighted and low-lighted tunnel-in-the-sky displays, as well as a less cluttered follow-me aircraft (FMA), through a series of curved approaches over rugged terrain. The results revealed that both tunnels supported better flight path tracking and lower workload levels than did the FMA because of the availability of more preview information. Increasing tunnel intensity had no benefit on tracking and, in fact, degraded traffic awareness because of clutter and attentional tunneling. In Experiment 2, 24 pilots flew a lowlighted tunnel configured according to different display sizes (small or large) and GFOVs (30 degrees or 60 degrees). Measures of flight path tracking and terrain awareness generally favored the 60 degrees GFOV; however, there were no effects of display size. Actual or potential applications of this research include understanding the impact of SVS properties on flight path tracking, traffic and terrain awareness, workload, and the allocation of attention. [ABSTRACT FROM AUTHOR]

Speech-based interaction is often recognized as appropriate for hands-busy, eyes-busy multitask situations. The objective of this study was to explore prompt-guided speech-based interaction and the impact of prompt modality on overall performance in such situations. A dual-task paradigm was employed, with tracking as a primary task and speech-based data input as a secondary task. There were three tracking conditions: no tracking, basic, and difficult tracking. Two prompt modalities were used for the speech interaction: a dialogue with spoken prompts and a dialogue with visual prompts. Data entry duration was longer with the speech prompts than with the visual prompts, regardless of whether or not there was tracking or its level of difficulty. However, when tracking was difficult, data entry duration was similar for both spoken and visual prompts. Tracking performance was also affected by the prompt modality, with poorer performance obtained when the prompts were visual. The findings are discussed in terms of multiple resource theory and the possible implications for speech-based interactions in multitask situations. Actual or potential applications of this research include the design of speech-based dialogues for multitask situations such as driving and other hands-busy, eyes-busy situations. [ABSTRACT FROM AUTHOR]

Tactical displays can quickly become cluttered with large numbers of symbols that can compromise effective monitoring. Here, we studied how heuristic automation can aid users by intelligently "decluttering" the display. In a realistic simulated naval air defense task, 27 experienced U.S. Navy users monitored a cluttered airspace and executed defensive responses against significant threats. An algorithm continuously evaluated aircraft for their levels of threat and decluttered the less threatening ones by dimming their symbols. Users appropriately distrusted and spot-checked the automation's assessments, and decluttering had very little effect on which aircraft were judged as significantly threatening. Nonetheless, decluttering improved the timeliness of responses to threatening aircraft by 25% as compared with a baseline display with no decluttering; it was especially beneficial for threats in more peripheral locations, and 25 of 27 participants preferred decluttering. Heuristic automation, when properly designed to guide users' attention by decluttering less important objects, may prove valuable in many cluttered monitoring situations, including air traffic management, crisis team management, and tactical situation awareness in general. [ABSTRACT FROM AUTHOR]

The relative contribution of number of fixations and fixation duration to reaction time in visual search was investigated. Ten participants (age 20-24 years) took part in each of two experiments. In Experiment 1, the experimental factors were display type (icon and file name), organization (arrangements with and without grouping), and number of stimuli presented (4, 8, and 16). In Experiment 2, a search task for a target stimulus (three prespecified random letters) was conducted, and the experimental factor was the display's layout complexity. Multiple regression analysis was used to examine whether reaction time was explained by a mediational model in which reaction time is mediated by eye movements and display features are not directly related to reaction time. The mediational model was not supported, and the effects of display features on reaction time were not attributable solely to eye movements. The interaction between number of fixations and fixation duration was also explored as a function of display features. As the display feature changed and the task became more difficult, the contribution of the number of fixations to explain the variation in reaction time became dominant for both experiments. Potential applications include measurements of cognitive ability, eye muscle balance disorders, and binocular fusion ability. [ABSTRACT FROM AUTHOR]

Postural responses were utilized as measures of the effectiveness of a wide-angle visual flow display in determining perceived spatial orientation (SO). The general experimental setup included a 150 degrees x 34 degrees wide-field display showing flight over computer-generated ground with horizon. Simulated roll maneuvers on this display induced postural sway in the observer that was registered by a head-tracker system. Two experiments with 16 participants in each investigated the effects of visual flow, display exclusions in the central visual field, and display extensions into the visual periphery. Clear vestibular and proprioceptive suppression effects were demonstrated on postural sway with the inclusion of visual flow of forward ego motion in roll maneuvers. Compared with the full view, up to 20 degrees x 20 degrees central field omission either did not reduce the effect or reduced the effect but, frequently, only moderately. Limiting the display area to 45 degrees in the horizontal dimension reduced display effectiveness significantly, whereas a 105 degrees area did not, compared with the full view. Utilizing postural responses as indications of visual display resonance with our SO mechanism, actual or potential applications of this research include the design of an interface integrating flight-adapted visual flow to counteract or reduce pilot spatial disorientation. [ABSTRACT FROM AUTHOR]

The time tunnel display design technique combines the benefits of configural displays (salient visual properties corresponding to critical domain semantics) with the benefits of temporal information (i.e., the value of variables and properties over time). In Experiment 1 a baseline configural display and a time tunnel display were evaluated using real-time measures of system control, fault detection, and state estimation in a simulated process control task. The results provided little evidence in support of the time tunnel format. In Experiment 2 access to the temporal context was limited: Participants performed the detection and estimation tasks with static "snapshots" of system states that had been generated in Experiment 1. The overall pattern of results indicates that the time tunnel display was more effective for state estimation tasks than was the baseline configural display and or a trend display. Issues in the design of temporal displays are discussed, including representational formats and the choice of temporal time frames. Issues in the evaluation of temporal displays are also discussed, including the role of temporal information and the critical nature of participants' access to this information. Actual or potential applications of this research include design techniques for improving graphical displays and methodological insights to guide future evaluations. [ABSTRACT FROM AUTHOR]

Input devices enable users to interact with systems. In two experiments, we assessed whether and how task demands and user age influenced task performance for a direct input device (touch screen) and an indirect input device (rotary encoder). In Experiment 1, 40 younger (18-28 years) and 40 middle-aged to older adults (51-65 years) performed tasks using controls such as sliders, up/down buttons, list boxes, and text boxes while using a system. The optimal input device to facilitate performance was dependent on the task being performed and the age of the user. In Experiment 2, touch screen use was assessed for 20 younger (19-23 years) and 20 older adults (51-70 years). Task demands were manipulated through button size, movement distance, direction, and type of movement. Performance was moderated by the age of the user and by task demands. Actual or potential applications of this research include guidance for the optimal selection of input devices for different user populations and task characteristics. [ABSTRACT FROM AUTHOR]

Factors that make response selection more difficult, most notably incompatibility between displays and controls, degrade performance. The cost of incompatibility on performance is often much greater for older than for younger adults. To design products that accommodate decreased response selection capabilities of older adults, designers need to understand the specific ways in which response selection processes change with age. The purpose of the present paper is to review research on age-related changes in stimulus-response compatibility and response precuing effects, the two effects that are most directly linked to basic response selection processes. Several specific aspects of response selection that are particularly harmful for older adults' performance are identified. Potential applications of this research include initial guidelines for minimizing the effects of those aspects when designing for older adults. [ABSTRACT FROM AUTHOR]

The digital imaging and communications in medicine (DICOM) standard proposed the grey-scale standard display function (GSDF) as a calibration tool for making the gradation characteristic of a radiographic output image consistent. This is designed in such a manner that the contrast visually recognised by observers (called psychophysical contrast) becomes a constant for alt digital driving levels. The DICOM standard calls such an ideal characteristic perceptual linearisation. The psychophysical gradient that can express the psychophysical contrast was introduced for the evaluation of the GSDF using a liquid crystal display monitor. Investigations regarding its ability to yield a constant psychophysical contrast, independent of the digital driving level change and under an actual observation environment, such as for clinical radiographic diagnosis in hospital, were carried out. The psychophysical gradients of the GSDF were obtained for two kinds of observation environment: one was a restricted environment such as in a dark room, under steady-state adaptation, using the sinusoidal grading pattern corresponding to the peak frequency of the human eye response. The other was an actual environment reflecting that encountered during clinical diagnosis in a hospital. As a result, the psychophysical gradient under the restricted environment became almost constant and independent of the change in digital driving level, i.e. perceptual linearisation could be satisfied. Furthermore, under the actual observation environment, the psycho-physical gradient decreased gradually with the increase in digital driving level, i.e. the perceptual linearisation could not be satisfied. The percentage decrease in the value of the psychophysical gradient at the maximum luminance area v\/as approximately 60% compared with that at the minimum luminance area. Accordingly, the GSDF is unsuitable as a calibration toot for the liquid crystal display monitor, which will be used in actual clinical diagnosis, as it cannot achieve 'perceptual linearisation' under the actual environment. For the purpose of clinical diagnosis, it is necessary to enlarge the physical gradient of GSDF further in the high digital driving level range (which relates to a high luminance area) to give an approximation that is as close to the idealised form as possible. [ABSTRACT FROM AUTHOR]

Objective: An exemplary sample of web sites relevant to personal health care and health promotion was chosen and evaluated.Methods: Both quantitative and qualitative data were converged to assess and rank the sites on nine attributes.Results: The sites provided a definitive range of value and variety of presentations, health care and health promotion information, and services covering the virtual choices currently available to users of the Internet.Conclusion: Discussion focused on methodological approaches and issues of web site evaluation serving the public interest, health care, and health promotion. [ABSTRACT FROM AUTHOR]

Background: The direction of visual gaze may be an important ergonomic factor that affects operative performance. We designed a study to determine whether a head-mounted display (HMD) worn by the surgeon would improve task performance and/or reduce muscle fatigue during a laparoscopic task when compared to the use of a traditional video monitor display (VMD).Methods: Surgical residents (n = 30) were enrolled in the study. A junior group, consisting of 15 postgraduate year (PGY) = 1 subjects with no previous laparoscopic experience, and a senior group, consisting of 15 PGY 4 and PGY 5 subjects with experience, completed a laparoscopic task that was repeated four times using the Computer Enhanced Laparoscopic Training System (CELTS). Groups alternated between using the HMD with the task placed in a downward frontal position and the VMD with the task at a 30 degrees lateral angle. The CELTS module assessed task completion time, depth perception, path length of instruments, response orientation, motion smoothness; the system then generated an overall score. Electromyography (EMG) was used to record sternocleidomastoid muscle activity. Display preference was surveyed.Results: The senior residents performed better than the junior residents overall on all parameters (p < 0.05) except for motion smoothness, where there was no difference. In both groups, the HMD significantly improved motion smoothness when compared to the VMD (p < 0.05). All other parameters were equal. There was less muscle fatigue when using the VMD (p < 0.05). We found that 66% of the junior residents but only 20% of the senior residents preferred the HMD.Conclusions: The CELTS module demonstrated evidence of construct validity by differentiating the performances of junior and senior residents. By aligning the surgeon's visual gaze with the instruments, HMD improved smoothness of motion. Experienced residents preferred the traditional monitor display. Although the VMD produced less muscle fatigue, inexperienced residents preferred the HMD, possibly because of improved smoothness of motion. [ABSTRACT FROM AUTHOR]

Visual layout has a strong impact on performance and is a critical factor in the design of graphical user interfaces (GUIs) and Web pages. Many design guidelines employed in Web page design were inherited from human performance literature and GUI design studies and practices. However, few studies have investigated the more specific patterns of performance with Web pages that may reflect some differences between Web page and GUI design. We investigated interactions among four visual layout factors in Web page design (quantity of links, alignment, grouping indications, and density) in two experiments: one with pages in Hebrew, entailing right-to-left reading, and the other with English pages, entailing left-to-right reading. Some performance patterns (measured by search times and eye movements) were similar between languages. Performance was particularly poor in pages with many links and variable densities, but it improved with the presence of uniform density. Alignment was not shown to be a performance-enhancing factor. The findings are discussed in terms of the similarities and differences in the impact of layout factors between GUIs and Web pages. Actual or potential applications of this research include specific guidelines for Web page design. [ABSTRACT FROM AUTHOR]

The nutrition label format currently used by consumers to make dietary-related decisions presents significant information-processing demands for integration-based decisions; however, those demands were not considered as primary factors when the format was adopted. Labels designed in accordance with known principles of cognitive psychology might enhance the kind of decision making that food labeling was intended to facilitate. Three experiments were designed on the basis of the proximity compatibility principle (PCP) to investigate the relationship between nutrition label format and decision making; the experiments involved two types of integration decisions and one type of filtering decision. Based on the PCP, decision performance was measured to test the overall hypothesis that matched task-display tandems would result in better decision performance than would mismatched tandems. In each experiment, a statistically significant increase in mean decision performance was found when the display design was cognitively matched to the demands of the task. Combined, the results from all three experiments support the general hypothesis that task-display matching is a design principle that may enhance the utility of nutrition labeling in nutrition-related decision making. Actual or potential applications of this research include developing robust display solutions that aid in less effortful assimilation of nutrition-related information for consumers. [ABSTRACT FROM AUTHOR]

Future air traffic management concepts envisage shared decision-making responsibilities between controllers and pilots, necessitating that controllers be supported by automated decision aids. Even as automation tools are being introduced, however, their impact on the air traffic controller is not well understood. The present experiments examined the effects of an aircraft-to-aircraft conflict decision aid on performance and mental workload of experienced, full-performance level controllers in a simulated Free Flight environment. Performance was examined with both reliable (Experiment 1) and inaccurate automation (Experiment 2). The aid improved controller performance and reduced mental workload when it functioned reliably. However, detection of a particular conflict was better under manual conditions than under automated conditions when the automation was imperfect. Potential or actual applications of the results include the design of automation and procedures for future air traffic control systems. [ABSTRACT FROM AUTHOR]

Information displays commonly use 2-D and 3-D objects even though the numbers represented are 1-D. This practice may be problematic because the psychophysical relation between perceived and physical magnitudes is generally nonlinear for areas and volumes. Nonetheless, this research shows that apparent 2-D and 3-D objects can produce linear psychophysical functions if only one dimension shows variation. Processing time increases with the number of dimensions in the objects that show variation, not with the apparent dimensionality. Indeed, when only one dimension showed variation, apparent 3-D objects were judged more quickly than were apparent 2-D or 1-D objects. These results present a challenge for computational models of size perception and have implications for the design of information displays. Actual or potential applications of this research include the design and use of statistical graphs and information displays; objects that display variation in more than one dimension should not be used to represent single (1-D) numerical variables if they are to be judged accurately and rapidly. [ABSTRACT FROM AUTHOR]

In-vehicle technologies (IVTs) create additional tasks for the driver. To the extent that these devices degrade driving performance, there will be safety concerns. This study examines the effects of display clutter from overlay, display separation, and modality on driving and IVT task performance. In a fixed-base simulator, 22 drivers drove different routes and responded to infrequent, unexpected road hazards while engaging in a phone number task presented by different displays. Visual displays were located on a head-up (overlaid on the visual horizon or adjacently, just above the vehicle hood) or head-down display (HDD) located near the midconsole. Alternatively, digits were presented auditorily. In general, there were no differences in performance for the adjacent and overlay displays; however, there were costs associated with the HDD and auditory display for some measures. In particular, responses to hazard events were slowed when drivers used the HDD. Overall, the adjacent display best supported performance on all relevant tasks. Potential applications of this research include the design of IVTs with respect to location and modality. [ABSTRACT FROM AUTHOR]