bluuebunny/crossref_metadata_2025 huggingface dataset:
The Effect of Haptic Feedback on Laparoscopic Suturing and Knot-tying: A Learning Curve Study
Authors: Zhou M. , Tse S. , Derevianko A. , Jones D.B. , Schwaitzberg S.D. , Cao C.G.L.
Published: January 2012

Haptic feedback has been shown to benefit performance in various laparoscopic surgery tasks. However, providing haptic feedback to novice trainees in the early stages of training may be distracting. A controlled experiment was conducted to investigate the effect of haptic feedback on the learning curve of a complex laparoscopic suturing and knot-tying task. It was hypothesized that subjects would perform better and reach the first plateau in the learning curve earlier with haptics than without. Twenty novices participated in eighteen one-hour training sessions. Results indicated that training with haptics was not significantly different from training without haptics after five hours of practice. However, those who learned with haptic feedback were more consistent in their task performance and had a shorter learning curve. Therefore, haptic feedback may be omitted in a laparoscopic surgical simulator in early training provided that extensive training is possible.
Separated versus Integrated Displays in Minimally-Invasive Surgery
Authors: DeLucia Patricia R. , Betts Eston T.
Published: January 2012

In minimally-invasive surgery (MIS), surgeons operate through small incisions while visualizing internal tissues with a camera or fiber optic scope. Compared with open surgery, MIS causes surgeons to engage in more frequent visual scanning to view multiple displays and other locations within the operating room. Visual scanning hastens fatigue, delays response time, and increases cognitive workload. We hypothesized that integrated displays– which present multiple images on a single monitor, would result in less fatigue, lower workload and better perceptual-motor performance than separated displays– which present images on physically separate monitors. Observers performed a pick-and-place task while monitoring “vital signs.” We compared performance between integrated and separated display conditions. Unexpectedly, results indicated that task completion time, fatigue and workload did not differ between display conditions. However, integrated displays did not degrade performance compared with separated displays. The implication is that integrated displays (i.e., fewer monitors) can be used in operating rooms. This is important because MIS requires more equipment than open surgery and operating rooms are typically cluttered with equipment.
Human Judgments of Stress State in Performance Settings
Authors: Helton William S. , Ellis Katrina
Published: January 2012

Many computational models of human performance are currently being developed. These models may be used to give machines a theory of human performance useful for human-machine teaming. The majority of these computational models are, however, insensitive to the human's stress-state. The present study explored whether humans have an intuitive theory of human stress that they use to predict other people's stress-states in performance contexts. Development of this model may enable machines to more effectively team with humans.
Object and Target Size Interactions in Placement Tasks
Authors: Srinivasan Divya , Martin Bernard
Published: January 2012

Hand movement trajectories and coordination are influenced by task characteristics. This study investigated hand kinematics in the performance of placement tasks using cylindrical objects. Performance was evaluated both in terms of movement time and the composition of multiple phases that make up the movement. Object size, target size, and movement distance were varied. For a given movement distance, movement time was the same for all objects when the difference between the target and object diameter was constant. Thus total movement time depended neither on the object size nor on the target width, but on the relationship between object and target width. However, for a constant object-target size relationship, closed-loop feedback corrections began earlier for smaller objects than for larger objects. Peak velocities of movements decreased with increase in object size.
The Effect of Stereotype Threat on Math Performance of Students with Different Majors
Authors: Kim Kahyun , Oh Kyunghui , Lee Dongsik , Oh Changgeun C.
Published: January 2012

Stereotype threat is the sub-conscious level of psychological activity due to emotional distress, which results in a decrement in performance. We tested the effect of stereotype threat on math performance in students with different majors. The difference between Korean students and Caucasian students was also examined. As a result, we found a tendency that students underperformed when they were threatened by the stereotype with respect to their majors and ethnicity. The implication of stereotype threat in academic environment is discussed.
Industrial Hand Wheel Valves: Effects of Height and Torque Direction on Maximum Torque and Muscle Activity
Authors: Wieszczyk Stacie M. , Marklin Richard W. , Sanchez Hector J.
Published: January 2012

Maximum torque and electromyography (EMG) of muscle activity when turning an 18 inch dia. hand wheel valve was measured at 3 different heights to determine the biomechanical loading on a worker's body. Twenty-four electric utility plant mechanics and operators participated in this study. The major independent variables were valve height (overhead, chest, and knee level) and torque direction (right and left). The major dependent variables were maximum torque (ft-lbs) and maximum voluntary contraction (%MVC) of EMG. Subject's exerted an average of 111 ft-lbs counterclockwise torque, which was greater that the mean 104 ft-lbs generated in the clockwise direction. Furthermore, participants exerted 13 to 16% greater torque at the overhead level than at chest level. When turning the valve counterclockwise (left), the %MVC of the left side muscles was greater than the right side muscles and vice versa for turning the valve clockwise (right).
Evaluation of the Logitech Wave Keyboard
Authors: Johnson Peter W. , Chen Han , Sauvage Sylvain
Published: January 2012

The purpose of this study was to determine whether there were any postural, performance and perceived comfort differences between a conventional, straight keyboard and a new ergonomic keyboard design developed by Logitech called the Wave. Twenty experienced touch typists from various occupations randomly used each keyboard for a period of 30 minutes. Wrist and forearm postures; typing speed and accuracy; comfort and keyboard preferences were evaluated before and after using each keyboard. Compared to the conventional, straight keyboard, the Wave Keyboard reduced wrist extension by 4.6 ± 1.5° (p < 0.01), ulnar deviation by 1.8 ± 0.7° (p = 0.02) and forearm pronation by 1.3 ± 0.7° (p = 0.08). There were small differences in typing speed (47.2 vs 45.6 WPM; p = 0.02) and no differences in accuracy (94.1% vs. 94.0%, p = 0.78) between the Wave and conventional, straight keyboard, respectively. Subjective comfort ratings were higher in the hand (p = 0. 02) and forearm (p = 0.03), and 85% of the subjects preferred the Wave Keyboard after 30 minutes of use. The results indicate that the Wave Keyboard achieved its design goal of reducing wrist extension, ulnar deviation and forearm pronation while improving comfort and not compromising typing speed and accuracy.
Interventions for Overhead Drilling in Construction
Authors: Rempel David , Star Demetra , Barr Alan , Gibbons Billy
Published: January 2012

Drilling into concrete or metal ceilings is a strenuous task that construction workers perform to hang ductwork, piping, and electrical equipment. The task can be associated with pain and disorders at the wrist, forearm, shoulder, neck and back due to the high forces and awkward postures applied during drilling. Previously we described field usability testing of a foot lever and an inverted drill press intervention device compared to the usual method for overhead drilling. Both interventions were rated as inferior to the usual method on setup time and mobility. For this study we used the inverted drill press design but tested 3 different wheeled bases. Construction workers (N=16) evaluated usability and upper body fatigue after using the 3 devices and the usual method in commercial construction settings. Across almost all usability measures the usual method received the poorest ratings and was associated with the greatest level of regional upper body fatigue. Overall, the wheeled ‘Collar Base’ intervention received the best usability ratings. The study demonstrates that several rounds of field testing may be necessary to identify health and safety interventions that both reduce musculoskeletal risk and are acceptable to workers.
Use of Tungsten to Reduce Hand-Arm Vibration Exposure in Aircraft Manufacturing
Authors: Jorgensen Michael J. , Khan Khurram S.
Published: January 2012

Rivet guns and bucking bars, which are used to set rivets during assembly of aircraft, results in high magnitudes of hand-arm vibration exposure, increasing the risk of upper extremity musculoskeletal disorders. The objective of this study was to identify rivet gun and bucking bar combinations that reduced vibration exposure and reduced muscle activity. A standard rivet gun and four vibration dampened rivet guns were assessed along with a traditional steel and vibration dampening tungsten bucking bar. Vibration dampened rivet guns resulted in lower vibration to “riveters”, however, use of these guns tended to result in higher vibration levels on the bucking bar. Tungsten bucking bars resulted in 34% less vibration on the bucking bar compared to the steel bar, as well as significantly less hand/wrist flexor muscle group activity. These findings indicate that to reduce overall vibration exposure, both the rivet gun vibration characteristics and the appropriate bucking bar material must be considered during a typical riveting operation.
Changes in the EMG of Low Back Muscles during Static Lumbar Flexion
Authors: Shin Gwanseob , D'Souza Clive R. , Liu Yu-Hsun
Published: January 2012

Prolonged and/or frequent lumbar flexion posture in industry has been known to contribute to the development of work-related low back pain or disorders but the specific biomechanics of this link has not been fully developed. In this study the effects of static lumbar flexion on back extensor muscles were evaluated by quantifying the changes in the flexion-relaxation onset angle, muscle activity level and the development of muscle fatigue associated with static lumbar flexion. Twenty healthy subjects performed submaximal isometric trunk extension exertions and isokinetic trunk flexion before and immediately after a 5 min continuous lumbar flexion posture while the trunk sagittal flexion angle and the myoelectric activities (EMG) of erector spinae muscles and latissimus dorsi muscles were recorded simultaneously. Results show an increase in the flexion-relaxation onset angle, normalized EMG of isometric extension, and decrease in the median power frequency of EMG as a consequence of the static lumbar flexion. It is suggested that back extensor muscles produce sustained low level contraction during static lumbar flexion, leading to muscular fatigue development. Together with creep deformed passive tissues of the low back and resultant spinal instability, the muscle fatigue of back extensors in static lumbar flexion may play a role in the development of low back pain or disorders.
Spatial Consumption and Kinematics for an Assisted Transfer in an Aircraft Lavatory
Authors: Philbrick Kenneth A. , Pavol Michael J.
Published: January 2012

Air travelers with mobility disabilities need greater access to onboard lavatories. To facilitate the design of compact, accessible aircraft lavatories, motion capture and spatial mapping techniques were used to investigate the effect of the wheelchair-to-toilet angle on spatial consumption and transferor kinematics during an assisted toilet transfer. Twenty-nine participants transferred a dummy within a simulated aircraft lavatory for wheelchair-to-toilet angles of 0° and 90°. The dimensions and shape of the spatial volume used, and the trunk kinematics of the transferor, differed between the 0° and 90° transfers. The smaller peak load moment arm for the 90° transfer was consistent with a lesser risk of low back injury to the transferor, suggesting that this transfer angle should be preferentially employed. The results also suggest that, by tailoring the design to a specific wheelchair-to-toilet angle, it may be possible to develop accessible lavatories that are more compact than those currently available.
Assessment of the Effect of a Pivoting Backrest and Activity Level on Spinal Shrinkage
Authors: Allsteel Scott Openshaw
Published: January 2012

Spinal shrinkage is commonly used as a measure of spinal loading. Spinal shrinkage has been shown to be affected by design features of chair backrests. A freely reclining (dynamic) backrest, passive movement of the lumbar spine via means of a cyclically inflated bladder and passive side-to-side rotation of the spine through a very small angle about its vertical axis at a low frequency via motion of the seat pan have all been shown to produce decreased spinal shrinkage.

In the current study we investigated the effect of two independent variables (pivoting backrest and activity level) on spinal shrinkage. The first variable was a pivoting backrest design with two use conditions, locked vs. unlocked. A locked backrest could recline but not pivot while an unlocked backrest could do both. Activity level consisted of an active condition during which the participant typed for 25 minutes and then moused for 25 minutes, which was interspersed every five minutes with a maximum forward reach to touch targets located at about 30, 60, 120, 150 180 degrees relative to the participant's centerline. During the passive activity condition, the participant only sat and typed.

It was hypothesized that the pivoting backrest would flex and extend the lumbar spine and/or stabilize the pelvis during the subjects' normal movement patterns and that it would have an effect similar to the previous spinal motion studies, which had found decreased spinal shrinkage as an effect of passive spinal motion. It was further hypothesized that the more active conditions would work synergistically with the pivoting backrest to retard spinal shrinkage.

Five individuals participated in the study, three males and two females.

Spinal shrinkage was statistically significantly less when the backrest pivot action was unlocked (t = 0.044) and nearly so during the active condition (t = 0.059). The pivoting backrest condition was also significantly preferred to the locked condition.
Spatial Memory as a Function of Action-Based and Perception-Based Similarity
Authors: Hurts Karel
Published: January 2012

Each of 34 subjects answered two spatial questions about each of 32 schematic maps from memory. The maps had been used before for performing two navigation tasks, resembling driving a car or flying a plane. The two questions were about the distance between and spatial orientation of two map cities. These cities either were on the same navigation path or belonged to different paths (defining action-similarity), and were either connected by lines or not (defining perceptual similarity). Results showed an expected effect of action-similarity on distance estimation (action-sharing made the cities seem closer to each other), but only when cities were not connected by lines. Cities that were connected by lines were judged to be closer to each other than non-connected cities (expected effect of perceptual similarity). No similarity effects were observed on the speed of verifying orientation statements. Theoretical and practical implications of these findings are indicated.
Performance on a Sustained Attention to Response Task
Authors: Helton William S. , Lopez Nicole , Tamminga Sarah
Published: January 2012

Robertson et al. (1997) modified the standard sustained attention target detection task, in which overt responses signal the detection of rare targets, into the sustained attention to response task (SART), in which withholding responses signals the detection of rare targets. We compared the SART format with the standard detection task format using local-global letter tasks. The SART response format is much more challenging than the standard format and demonstrates different performance changes over time than the standard format. These findings may further our understanding of human behavior in high target probability, low neutral signal probability environments, such as modern combat.
Effects of Automated Scanning in a Search and Rescue Detection Task
Authors: Keillor Jocelyn , Haque Fatin , Lamb Matthew , Pavlovic Nada
Published: January 2012

Traditionally, search and rescue (SAR) technicians have conducted search by directly viewing the terrain below the aircraft. Defence R&D Canada is developing a multi-sensor imaging system for SAR that would replace this direct “out-the-window” inspection under low visibility conditions. The system could be designed to automate the sweep of the sensor across the terrain in order to minimize operator workload and to ensure that the sensor covers all of the area to be searched. In a previous prototype, the operator controlled the sweep of the sensor through the use of a joystick, adjusting the speed and direction of the sensor in real time. That interface permitted the operator to both cover the terrain and maximize the detection potential targets by moving the sensor more slowly over portions of the display that was more complex or contained cues to the potential presence of a target. The present study was designed to determine whether automation of the sweep function would compromise detection performance by preventing the operator from adjusting the motion of the sensor to make use of the visual information contained in the scene. The results demonstrate that detection is indeed superior when the sensor sweep is controlled by the operator, and that this effect is modulated by the detectability (contrast) of the target. Additionally, it was observed that the terrain could be more effectively covered under operator control, such that the operator was able to adjust the motion of the sensor to match changes in the visibility of the terrain.
Cerebral Blood Flow Velocity and Subjective State as Indices of Resource Utilization during Sustained Driving
Authors: Reinerman Lauren E. , Warm Joel S. , Matthews Gerald , Langheim Lisa K.
Published: January 2012

Recent studies from our laboratory have shown that the vigilance decrement, the decline in signal detection over time that typifies vigilance performance, is accompanied by a decline in Cerebral Blood Flow Velocity (CBFV) measured by transcranial Doppler ultrasonography and by an increase in stress measured by the Dundee Stress State Questionnaire (DSSQ). These studies were restricted to single vigilance tasks. In operational settings, such as driving, vigilance is often combined with other task components. Therefore, the aim for the present study was to generalize the findings from the earlier studies to a simulated driving task. As in the earlier studies, temporal declines in performance efficiency, indexed in this case by variability in lateral position, were accompanied by declines in CBFV and increased feelings of distress and task disengagment on the DSSQ. The results suggest that resource utilization patterns found with single vigilance tasks may extend to dynamic performance situations in which vigilance is one of several task elements.
Multisensory Integration with a Head-Mounted Display and Auditory Display
Authors: Thompson Matthew B. , Sanderson Penelope M.
Published: January 2012

Human operators who use head-mounted displays (HMDs) in their work may benefit from auditory support. It is unclear whether auditory support is better delivered in free-field or via earpiece, and what the effect of walking is. To examine this problem, a novel multisensory integration task was created in which participants identified mismatches between sounds and visual information on an HMD. Participants listened to the sounds either via earpiece or free-field while they either sat or walked about the test room. When using an earpiece, participants performed the mismatch task equally well whether walking or sitting, but when using free-field sound, participants performed the task significantly worse when walking than when sitting. The worse performance for participants using free-field sound while walking may relate to spatial and motion inconsistencies between the sound and vision or because of misperceptions of the time at which the sounds occurred. The results underscore the need for representative design of experiments exploring multisensory integration and they suggest auditory conditions that might influence effective multisensory integration with HMDs.
Force and Impulse Production during the Use of a Touch Screen by Individuals with Motor Control Disabilities
Authors: Irwin Curt B. , Meyer Robert H. , Yen Thomas Y. , Kelso David P. , Sesto Mary E.
Published: January 2012

People are increasingly required to interact with touch screens at places ranging from grocery stores to airport kiosks. To date, most of the usability research related to touch screens has included young, healthy subjects. Using novel instrumentation consisting of a force plate and a touch screen, a number entry study examined finger-touch screen interaction by participants with Cerebral Palsy, Multiple Sclerosis, and non-disabled controls. Timing data as well as peak forces and impulses in three dimensions were collected for each touch. The results indicate that, although average peak force vector magnitudes, impulses, and dwell times are similar between the groups, there are significant differences within the same three variables by button size. Average peak force vector magnitude increased by 11 percent while the average vector impulse decreased by 29 percent from the smallest to the largest button size. The average dwell time also decreased 23 percent from the smallest to the largest button size.
The Effect of Automation Reliability on User Automation Trust and Reliance in a Search-and-Rescue Scenario
Authors: Ross Jennifer M. , Szalma James L. , Hancock Peter A. , Barnett John S. , Taylor Grant
Published: January 2012

Advances in modern day technology are rapidly increasing the ability of engineers to automate ever more complicated tasks. Often these automated aids are paired with human operators who can supervise their work to ensure that it is free of errors and to even take control of the system if it malfunctions (e.g., pilots supervising an autopilot feature). The goal of this collaboration, between humans and machines, is that it can enhance performance beyond what would be possible by either alone. Arguably the success of this partnership depends in part upon attributions an operator develops that help guide their interaction with the automation. One particular factor that has been shown to guide operator reliance on an automated ‘teammate’ is trust. The following study examined 140 participants performing a simulated search-and-rescue task. The goal of this experiment was to examine the relationship between automated agent's reliability, operator trust, operator reliance, and performance scores. Results indicated that greater automation reliability is positively correlated with greater user reliance ( r = .66), perceived trust ( r = .21), and performance scores ( r = .34). These results indicate that more reliable aids are rated as significantly higher in terms of perceived trust and relied upon more than less reliable aids. Additionally, the size of the effect is much larger for operator behaviors (i.e., reliance) compared to more subjective measures (i.e., self-reported trust).
Hatch Size Evaluation for the Altair Lunar Sortie Habitat
Authors: Thompson Shelby , Litaker Harry , Archer Ronald , Howard Robert
Published: January 2012

Issues of moving through hatchways and related design problems of hatch size and shape were investigated for the Altair lunar habitat. To insure proper usability and safety, the goal of the current study was to understand the critical dimensions necessary for proper translation through the hatch by manipulating size (height, width, step over height, and overall height) and shape (rectangular and circular). A single participant donning a pressurized rear-entry integrated (REI) Extravehicular Activity (EVA) suit was timed and video recorded as participant accomplished various translations through a mockup hatch. Objective performance measures consisted of time and contact data with the hatch, while subjective data was obtained using the Cooper-Harper Qualities Ratings, Corlett and Bishop Discomfort Scale, a Physical Effort scale, and a functionality questionnaire. Correlation analysis discovered a significant relationship between the hatch dimension of height and all of the performance measures, as well as, step over and overall height with some of the dependent scores.
Communications-based Performance Assessment for Air and Space Operations Centers: Preliminary Research
Authors: Weil Shawn A. , Duchon Andrew , Duran Jasmine Ledell , Cooke Nancy J. , Gorman Jamie C. , Winner Jennifer L.
Published: January 2012

The use of electronic chat has become widespread for both social and work applications. Increasingly, individuals using text chat applications engage in multiple simultaneous conversations with co-workers to accomplish complex tasks. This is especially true in the military, where it is used extensively in Navy, Army, and Air Force command and control environments. The current effort seeks to leverage stored communications from electronic chat to examine the relationship between communication flow and team performance. ChainMaster, a tool that looks at process elements of communication, was used to investigate the relationship between communication patterns and other performance measures in the context of an emulated Air and Space Operations Center (AOC). Results indicated a modest relationship between communications patterns and measures of performance. Applicability of these results in other domains is discussed.
Factors Related to Drivers' Self-Reported Willingness to Engage in Distracting In-Vehicle Activities
Authors: Horrey William J. , Lesch Mary F.
Published: January 2012

Studies of driver distraction are prevalent and the findings show that, in general, driving performance is degraded when drivers perform concurrent activities. In the real world, drivers often control how in-vehicle tasks are initiated and performed. That is, drivers themselves elect whether or not to engage in these activities. The current study reports on some of the factors that are related to drivers' self-reported willingness to perform distracting activities while driving. Forty participants observed a series of short driving videos and subsequently reported how willing they would be in performing these activities in the given context. We also gathered demographic and driving history information, along with different personality scales and attitudes and opinions regarding various in-vehicle distractions. In general, the willingness to engage in distracting activities was strongly associated with past behavior with respect to distractions ( r = .78), confidence in their ability to deal with distractions ( r = .52), lower estimates of the impact of in-vehicle tasks on performance ( r = -.42 to -.35), and tendencies towards sensation seeking ( r = .28), among others. A step-wise regression analysis indicated that a subset of these factors accounted for 76% of the variance in willingness ratings. Implications for driver safety and potential interventions are discussed.
The Effect of Input Device on First-Person Shooter Target Acquisition
Authors: Lenz Kelsi M. , Chaparro Alex , Chaparro Barbara S.
Published: January 2012

Gaming has become a billion dollar industry over the past several years. First-person shooter (FPS) games have become increasingly popular, and the player's ability to accurately control their weapon and acquire targets quickly is very important. This was a two part study that assessed the effect of input device on FPS target acquisition. Study 1 assessed players' accuracy on eliminating targets in the FPS game Star Wars Battlefront II™ using three different input devices (mouse, Playstation 2 (PS2) controller, and joystick) with two different weapon types (sniper rifle and blaster rifle). No significant differences in performance were found between input devices. However, participants did take fewer shots in the sniper rifle condition when using the joystick. There was a significant difference found between the rifle types, with participants taking fewer shots and less time to eliminate targets when using the sniper rifle. Trends observed in the results suggest different input devices are more effective for eliminating static versus moving targets. Study 2 assessed players' who were experts with one of the input devices performance at the same task using only the blaster rifle. Joystick users were trained on the device before completing the tasks to assure they were at the same level of performance as the mouse and PS2 participants. No significant differences were found between devices for time to kill targets. However, participants using the mouse took significantly fewer shots than those using either the joystick or the PS2 controller. This suggests that after training the mouse is the most efficient input device for first-person shooter target acquisition.
Analysis of Human Information Acquisition Behavior for Natural Gaze-Based Wheelchair Control
Authors: Jipp Meike , Bartolein Christian , Badreddin Essameddin
Published: January 2012

Especially for severely disabled people, a powered wheelchair is an important means to participate in societal life and live as far as possible independently. To achieve this goal for users, who cannot operate their wheelchair with the traditional joystick or specialty controls, methods have been developed to enable steering the wheelchair on the basis of the user's gaze behavior. While existing approaches require the user to adapt his/her gaze behavior to match the characteristics of the human-technology interaction and/or only provide reasoning about the desired motion direction of the user, the conducted study gives crucial input about the relationship between the gaze behavior of wheelchair users and the - from the user - desired goal position as well as his/her anticipated mission. Implications for a natural gaze-based assistance system for electrically powered wheelchairs are drawn, which allows reasoning on the user's behavioral goal position and his/her current mission.
Human Error Quantification Using Performance Shaping Factors in the SPAR-H Method
Authors: Blackman Harold S. , Gertman David I. , Boring Ronald L.
Published: January 2012

This paper describes a cognitively based human reliability analysis (HRA) quantification technique for estimating the human error probabilities (HEPs) associated with operator and crew actions at nuclear power plants. The method described here, Standardized Plant Analysis Risk-Human Reliability Analysis (SPAR- H) method, was developed to aid in characterizing and quantifying human performance at nuclear power plants. The intent was to develop a defensible method that would consider all factors that may influence performance. In the SPAR-H approach, calculation of HEP rates is especially straightforward, starting with pre-defined nominal error rates for cognitive vs. action-oriented tasks, and incorporating performance shaping factor multipliers upon those nominal error rates.
Methodological Considerations for Using the English XL Tribometer for Post Hoc Slip-and-Fall Evaluations
Authors: Kubose Tate , Krauss David
Published: January 2012

We examined several variables that can affect slip-resistance measurements obtained using the English XL tribometer to illustrate the importance of implementing the proper controls when using the device to evaluate a slip-and-fall incident. We measured slip resistance at two different locations on the same surface, under wet and dry conditions, with the tribometer oriented in eight different directions per location. Our results showed that location, direction, and surface wetness can affect slip resistance measurements, but the effects interact with each other in unpredictable ways. Discussion focuses on the importance of considering direction as well as location of a particular slip-and-fall, rather than strict adherence to ASTM F1679–04: Standard Test Method for Using a Variable Incidence Tribometer (VIT). We conclude that it is important to consider both location and direction when using the tribometer in analysis of any specific incident occurring on non-uniform surfaces.
“The Real World” HF/E: Understanding the Realities of Your First Professional Job
Authors: Shapiro Ronald G. , Andre Anthony D. , Agarwal Anshu , Artis Sharnnia , Hoeft Raegan M.
Published: January 2012

Welcome to the Fifteenth Annual Human Factors and Ergonomics Society Student Career Panel. While our typical career panel emphasizes what one should do before graduation to prepare for a career, it is equally important to know what to do once one starts to work on the job. Thus, this year's paper will begin with a section by Anthony Andre, emphasizing the final preparations for a new professional career as well as the job search itself. The remaining papers will discuss what to do after beginning one's career. Anshu Agarwal will discuss the first 90 days on the job, Sharnnia Artis will discuss the remainder of the first year, and Raegan Hoeft will discuss the second year. Ron Shapiro will close by focusing on the subsequent term of a given job. This paper will present tried and tested techniques as well as new ideas towards preparing for, finding, and experiencing the ideal career path and position. At the annual meeting panel discussion, panelists will provide a brief introduction and then entertain questions from the audience regarding career preparation while still in school as well as success factors on the job.
Crossmodal Links in Attention in the Driving Environment: The Roles of Cueing Modality, Signal Timing, and Workload
Authors: Tilak Rohan , Xholi Ilir , Schowalter Diane , Ferris Thomas , Hameed Shameem , Sarter Nadine
Published: January 2012

Multimodal information presentation has been proposed as a means to support timesharing in complex data-rich environments. To ensure the effectiveness of this approach, it is necessary to consider performance effects of recently discovered crossmodal spatial and temporal links in attention, as well as their interaction with other performance-shaping factors. The main goals of this research were to confirm that performance effects of crossmodal links in spatial attention scale to complex environments and to examine how these effects vary as a function of cue modality, signal timing, and workload. In the present study, set in a driving simulation, spatially valid and invalid auditory and tactile cues preceded the presentation of visual targets at various stimulus-onset asynchronies and under different levels of workload induced by simulated wind gusts of varied intensity. The findings from this experiment confirm that visual target identification accuracies and response times are, overall, more accurate and faster when validly-cued. Significant interactions were found between cue validity, stimulus onset asynchrony (SOA), and cue modality, such that valid tactile cueing is most beneficial at shorter (100–200 ms) SOAs, while valid auditory cueing resulted in faster responses than invalid cueing at 500 ms SOAs, but slower responses at 1000 ms SOAs. Tactile error rates were significantly higher than auditory error rates at various interactions of modality and SOA. These findings were robust across all workload conditions. They highlight the need for context-sensitive information presentation and can inform the design of multimodal interfaces for a wide range of application domains.
Traffic Sign Legibility for Different Sign Background Colors: Results of an Open Road Study at Freeway Speeds
Authors: Funkhouser Dillon , Chrysler Susan , Nelson Alicia , Park Eun Sug
Published: January 2012

Transportation agencies have been considering the use of a purple sign background color to denote that the roadway is tolled. Prior studies have shown a driver preference for a unique color for the toll road category. Concerns about the legibility of purple signs have been raised due to their brightness and contrast ratio with a white legend. The current study performed an evaluation of the legibility and recognition of purple and green freeway guide signs during daytime and nighttime driving in the Houston, TX area. Forty-eight participants drove an instrumented vehicle in open traffic and read traffic signs along a toll road with purple signs on one segment and green signs on another. Results showed no significant difference in legibility distance between signs with purple and green backgrounds. An analysis of recognition distances for advance guide signs marking ramps to the toll road also showed no difference between purple and green signs. These results support the implementation of this new color without any loss in legibility.
Effect of In-Vehicle Touch Screen Position on Driver Performance
Authors: Fuller Helen , Tsimhoni Omer , Reed Matthew P.
Published: January 2012

The effect of touch-screen monitor placement on in-vehicle task performance and driving performance was examined in a driving simulator. Sixteen subjects drove behind a lead vehicle while interacting with a menu-based interface that required looking, planning, reaching, and touching. The vehicle dynamics of the simulator were adjusted to simulate two vehicles: a normal-weight car and a heavy-weight truck. The monitor was placed in one of four different positions that had varying levels of visual and physical difficulty. Two positions had a short reach distance and two had a long reach distance. For each monitor pair, one position had a shorter visual distance from the road ahead and one had a longer visual distance. Monitor positions that were at greater visual distances from the road ahead or that were farther physically from the subject resulted in longer in-vehicle task completion times. The average task time increased from 17.8 seconds for the closest monitor position to 35.1 seconds for the farthest. Although driving performance, as measured by the RMS error between the subject vehicle and the lead vehicle and delay in speed change, was adversely affected by performance of an in-vehicle task, it was relatively unaffected by monitor position.
Human Factors and Systems Engineering – Integrating for Successful Systems Development
Authors: Narkevicius Jennifer McGovern
Published: January 2012

All systems are populated by users, operators, maintainers, support personnel, managers, supervisors, and others. Therefore Systems Design must include human considerations via Human Factors participation in Human Systems Integration tradeoffs and by extension the Systems Engineering process. This paper explores the contributions of Human Factors and Human Systems Integration in the Systems Design process and the greater Systems Engineering Process. The linkages between Human Factors, Human Systems Integration, and Systems Engineering will be illustrated and the need for those linkages to be strengthened by tools will be discussed.
Developing Quantitative Metrics to Predict Users' Perceptions of Interface Design
Authors: Zheng Xianjun Sam , Chakraborty Ishani , Lin James J.W. , Rauschenberger Robert
Published: January 2012

Users' perceptions of an interface play an important role in influencing their acceptance of a product. Currently, however, designers lack an objective method to predict users' perceptions and to guide decisions during the design process. We propose a statistical image analysis method that takes the user interface as an input and computes image features that can be used to inform design. Based on these metrics, we then implemented a supervised learning algorithm to predict users' perceptions. We tested this method with a case study involving car infotainment systems. The results showed that the algorithm can capture users' perceptual ratings quite well, in particular for the perceptions of clutter vs. organized, and aggressive vs. calm. We discuss the implications of this computational method for UI design.
Older Adults' Training Preferences for Learning to Use Technology
Authors: Mitzner Tracy L. , Fausset Cara Bailey , Boron Julie B. , Adams Anne E. , Dijkstra Katinka , Lee Chin Chin , Rogers Wendy A. , Fisk Arthur D.
Published: January 2012

Older adults may benefit from using technology in their everyday lives. However, adults over 65 may need more training than their younger counterparts given they have had less experience with technology. In this study, 113 adults between the ages of 65 and 85 participated in focus group interviews discussing their training needs and preferences for technology items used in the home. Participants expressed an interest in receiving additional training, particularly for specific tasks. Participants also discussed preferences for various characteristics of training, such as who should conduct the training and for their preferred method of training. One of the most frequently discussed preferences was for self-training using text materials, such as a manual.
Effects of Training Modality on Military Vehicle Identification in a Virtual Environment
Authors: Keebler Joseph R. , Lee Sciarini , Jenstch Florian , Fincannon Thomas , Nicholson Denise
Published: January 2012

Using the Deployable Virtual Training Environment (DVTE) simulation suite, we investigated the effects of two different training types (military issued cards and 1:35 scale models) on participant's abilities to correctly identify military vehicles. Using independent samples t-tests, it was found that neither the cards nor scale models of the same vehicles had an effect on identification scores when the participants were tested in the DVTE environment. We then compared this current study to a previous study that tested the two training modalities using the same media instead of a virtual environment. We found results for recognition demonstrating that either training was sufficient for predicting performance in the virtual environment. Performance for identifying the vehicles was significant only when the training and testing modality were the same.
The Effects of Input Device and Latency on Ability to Effectively Pilot a Simulated Micro-UAV
Authors: Billings Deborah R. , Durlach Paula J.
Published: January 2012

The effects of input device and latency during training to manually pilot a simulated micro-unmanned aerial vehicle (MAV) were investigated. In our prior simulation research, MAV missions were completed more quickly when trainees used a game controller than when they used a mouse. This experiment investigated whether this difference would persist when participants were tested in a novel environment and when some realistic latency was imposed between input command and MAV response. Fifty-six participants were trained to operate a MAV in one simulated environment and then tested in a novel environment. Four between-group conditions were examined, formed by crossing two 2-level factors: input device (mouse vs. game controller) and latency period (no time delay vs. 500 ms delay). The effects of input device replicated our prior research and also transferred to the novel environment; no substantial effects of delay were found.
An “Audio Annotation” Technique for Intuitive Communication in Spatial Tasks
Authors: Ephrem Adrienne J. , Finomore Victor S. , Gilkey Robert H. , Newton Rihana M. , Romigh Griffin D. , Simpson Brian D. , Brungart Douglas S. , Cowgill Jeffrey L.
Published: January 2012

Navigating in any environment can be a very tedious task, and it becomes considerably more difficult when the environment is unfamiliar or when it contains threats that could possibly jeopardize the success of the mission. Often in difficult navigation environments there are external sensors present in the area that could provide critical information to the ground operator. The challenge is to find a way to transmit this information to the ground operator in an intuitive, timely, and unambiguous manner. In this study, we explore a technique called “audio annotation” where the sensor information is transmitted to a remote observer who processes it and relays it verbally to an operator on the ground. Spatial information can be conveyed intuitively by using a spatial audio display to project the apparent location of the remote observer's voice to an arbitrary location relative to the ground operator. The current study compared the “audio annotation” technique to standard monaural communications in a task that required a remote observer with a high-level view of the environment to assist a ground operator to avoid threats while locating a downed pilot in an urban environment. The overall performance in the audio annotation condition was found to be superior to the standard monaural condition.
The Effects of Geographic Familiarity and Map Complexity on Mental Rotation
Authors: Fercho Kelene , Peterson Doug
Published: January 2012

The present study examined the effects of stimulus complexity and geographic familiarity upon mental rotation while simultaneously engaging participants in a simulated flight task. Nineteen licensed pilots (16 men and 3 women) participated in a mental rotation task. Results indicated a piecemeal strategy was used with maps representing an unfamiliar geographic area. Further, an exploratory analysis indicated that unfamiliar condition participants may have used a strategy described by Loftus (1978), in which two rotations are performed - the first from the cue orientation to the nearest cardinal direction, and the second from the cardinal direction to the target orientation. Those in the familiar condition used a nonrotational strategy (i.e., a piecemeal comparison between the presented map and their cognitive map) to perform the rotation task. Unfamiliar condition flight performance was more affected by the experimental manipulations. This suggests that cognitive transformations performed on unfamiliar geographic images are cognitively more demanding than those using familiar geographic images.
Adaptive Boundary Aids in Complex Air Combat Scenarios
Authors: Guarino Sean L. , Harper Karen , Roth Emilie , Liu Dahai , Vincenzi Dennis
Published: January 2012

Advances in aircraft operational capabilities have led to a dramatic increase in the operational tempo facing air combat aviators, which has in turn led to SA failures, particularly with respect to secondary information. For example, when engaging an air threat, aviators will often overlook key information such as geopolitical boundaries, resulting in potential infractions of rules of engagement. In a previous study, we investigated an Adaptive Border Display designed to maintain awareness of these boundaries, and found that it was not helpful. However, in that study, our scenarios did not create the high workload situations in which pilots lose track of these boundaries. In this study, we used significantly more complex scenarios to investigate this display, creating high workload situations for the aviators. Results showed that in these situations, the Adaptive Border display had a significant effect on improving aviator performance.