bluuebunny/crossref_metadata_2025 huggingface dataset:
An Evaluation of "Talking Signs" for the Blind
Authors: Brabyn Lesley A. , Brabyn John A.
Published: July 2017

A new orientation system for the blind was evaluated in terms of its efficiency in assisting goal-oriented travel performance. Blind subjects were asked to locate rooms independently on one floor of a large building. In one condition, the subjects used audio speech signals presented via an infrared transmitter and hand-held receiver; in the other condition they used conventional raised-print labels. Performance, in terms of time required to reach goal, was compared for the two conditions. The results indicate that it took significantly less time to reach the goal locations when subjects used the audio system. The role of such a system in aiding the orientation and travel efficiency of blind pedestrians is discussed, as are additional applications of the system, effective techniques developed by the subjects for using the device, and suggested improvements for future versions.
Whole-Body Vibration and International Standard ISO 2631: A Critique
Authors: Oborne D. J.
Published: July 2017

The present International Standard for human response to whole-body vibration (ISO 2631) has been in effect since 1974. This standard is used to assess the effect of environmental vibration on operator health, efficiency, and comfort. This paper discusses the derivation of the standard and the bases upon which its main propositions were formed. Some aspects of the standard are supported by empirical data; however, this paper highlights a number of deficiencies that call into question the appropriateness of the standard for application. In particular, the shape of the frequency weighting curves, the concept of time dependency, the response criteria, and the weighting method for nonsinusoidal vibrations are examined in the light of published experimental findings.
The Effects of Extended Practice on the Evaluation of Visual Display Codes
Authors: Christ Richard E. , Corso Gregory M.
Published: July 2017

A series of nine experiments are reported in which highly practiced subjects were used to investigate the use of letters, digits, familiar geometric shapes, and colored dots as coding dimensions in visual displays. These experiments used single-code and dual-code displays in three isolated tasks (choice reaction, search and locate, and identification-memory) and in a multiple task that combined the three tasks in an irregularly alternating sequence. The results of these experiments provided no basis for concluding that any particular code has a general advantage or disadvantage over any other. Furthermore, when there were differences in performance with different codes, there was a tendency for practice to attenuate those differences. It is concluded that the relative effectiveness of different visual codes varies as a function of practice, other display conditions, the tasks, and the dependent measure used to make the comparison.
The Dark Focus of the Human Eye and Its Relationship to Age and Visual Defect
Authors: Simonelli Nicholas M.
Published: July 2017

The effects of age and ametropia (nearsightedness or farsightedness) on the dark focus of visual accommodation have not been extensively investigated. Participant pools of students are generally screened and their vision "standardized" by testing them while they wear their corrective lenses. In this study, nearsighted and farsighted subjects were measured for their near points, far points, and dark focuses. It was found that the more nearsighted the eye the larger the dark focus shift. Age was also found to have a relationship to the dark focus. Older individuals tended to have a smaller dark focus shift, and the dark focus was found to recede with age at roughly the same rate as the far point.
Driver Steering Reaction Time to Abrupt-Onset Crosswinds, as Measured In a Moving-Base Driving Simulator
Authors: Wierwille Walter W. , Casali John G. , Repa Brian S.
Published: July 2017

A moving-base driving simulator was used in three experiments involving driver reaction time (RT) to simulated crosswind disturbances. Analyses were conducted on driver steering reaction time (RT) to the disturbances. Experiment 1 revealed that RT was significantly shorter when physical-motion cues were present. A second variable, vehicle yaw rate rise time, showed no effect. In Experiment 2, design parameters influencing aerodynamic behavior of a vehicle were adjusted. RT increased as the vehicle center of pressure (point of crosslvind application) moved rearward (rom the (ront axle. However, rearward movement of the center of pressure also produced less disturbance of the vehicle itself Changes in understeer and steering sensitivity yielded no significant effect. In Experiment 3, both uninitiated drivers and drivers with time on task were examined. Neither the first exposure to a step gust nor driving time up to 150 mirl caused significant changes in RT when perfurmance was compared with that of practiced, fresh drivers. Interexperiment comparisons using crosswind amplitude and shape as independent variables demonstrated that the amplitude and rise time of the crosswinds were critical determinants of steering RT.
Sign Registration in Daytime and Nighttime Driving
Authors: Shinar David , Drory Amos
Published: July 2017

Drivers were stopped 200 m after passing a warning sign and were tested for recall and recognition of the sign. It was predicted that at night, when the view of the road ahead is severely restricted, sign registration levels would be higher than during the day, when drivers can obtain most of their information directly from their view of the road ahead. The results supported this hypothesis; sign recall levels ranged from 3 to 6% during the day and from 14 to 18% at night. Other variables that were measured (sign content, roadway environments, and subjective levels of fatigue and boredom) had no significant effects on sign registration.
The Influence of Camera Configuration on Preference
Authors: Faulkner Terrence W. , Rice Thomas M. , Heron William K.
Published: July 2017

A series of three experiments was conducted to compare alternate configurations for a new kind of camera for amateur photographers. Cluster analysis and multidimensional scaling techniques were used to provide an understanding of the configuration factors that influence preference. The results from each experiment were used to generate an improved set of models for testing in the subsequent experiment.
Document Design for Technical Job Tasks: An Evaluation
Authors: Duffy Thomas M. , Curran Thomas E. , Sass Del
Published: July 2017

Document design strategies have typically focused on either procedural text or instructional text. This study evaluates the design of yet another class of text, the nonprocedural job text. A nine-page segment of a technical text was redesigned by three separate companies, each specializing in document design. The companies were given complete freedom in redesigning the text. Evaluation was carried out by means of paper-and-pencil tests of fact comprehension and of inferential comprehension for fault isolation tasks. Both speed and accuracy were measured in these "open book" tests. None of the redesigns resulted in more accurate or faster comprehension performance. In fact, one of the redesigns was less comprehensible than the original, as measured on each test. The results are discussed in terms of "reading to do" versus "reading to learn," and in terms of the potential moderating effect of the readers' "format schema" for the traditional design.
Retention of Military Tasks: A Review
Authors: Hagman Joseph D. , Rose Andrew M.
Published: July 2017

Thirteen experiments conducted or sponsored by the Army Research Institute are reviewed. For the most part, these experiments have examined retention of military tasks performed in an operational environment. They provide empirical data on the effects of method, task, and ability variables that influence attempts to improve retention through training. These data provide information useful to trainers and training-program developers in deciding how, what, and whom to train to enhance retention and achieve greater training management effectiveness.
Individual Differences in Multiple-Task Performance as a Function of Response Strategy
Authors: Damos Diane L. , Smist Thomas E. , Bittner Alvah C.
Published: July 2017

This experiment demonstrates that the response strategies used to perform a discrete task combination reflect individual differences in multiple- but not single-task information processing. Subjects performed a discrete task combination on two consecutive days. On Day 1, the strategy was identified as a simultaneous, an alternating, or a massed response strategy. On Day 2, some of the subjects were asked to change strategy. Comparisons among subjects using the same strategy on Day 2 indicate that subjects who use the massed response strategy naturally do not perform as well under multiple-task conditions as do the other subjects, although their single-task performance is not significantly poorer. Subsequent analyses revealed that massed response subjects may have poorer time-sharing skills than other subjects.
Subjective Pilot Workload Assessment
Authors: Rehmann Jacqueline T. , Stein Earl S. , Rosenberg Bruce L.
Published: July 2017

Traditional subjective pilot workload measures have stressed postflight questionnaires. An alternative method that is less dependent on memory was evaluated in two experiments. In the first study, pilots and nonpilots made workload evaluations each minute during a critical tracking task. Results indicate that their responses were directly related to the experimentally controlled difficulty level, whereas posltask questionnaire responses were much less accurate. In a second study, the workload assessment device was introduced into the cockpit of a general aviation cockpit simulator, to detennine if pilots could differentiate between three flights in which the level of difficulty varied. It was found that pilot workload judgments and response latencies were related to the experimentally induced difficulty level. As hypothesized, the more difficult flights generated higher mean workload responses and longer latencies.
Display Station Anthropometrics: Preferred Height and Angle Settings of CRT and Keyboard
Authors: Miller Win , Suther Thomas W.
Published: July 2017

This study investigates display station physical adjustments preferred by a sample of visual display terminal operators. Participants in the study were selected to assure representation of extremely short and extremely tall persons, as well as persons of midrange physical stature. Individual operators were led through a step-by-step sequence to determine their preferred initial settings of seat height, keyboard height and slope angle, and CRT height and tilt angle. Each operator then performed a brief text input task, after which final preferred adjustments were measured.

Intermeasure correlation strongly suggest that “flat” (low slope angle) keyboards are inappropriate for short operators who select low seat heights. In addition, the keyboard angle adjustments preferred by most operators substantially exceed a current German ergonomic display station requirement.
Maximum Frequencies Acceptable to Males for One-Handed Horizontal Lifting in the Sagittal Plane
Authors: Mital Anil , Asfour S. S.
Published: July 2017

Male volunteers participated in an experiment to determine the maximum frequencies they could maintain for 2 h while lifting in the horizontal-sagittal plane using the preferred hand. The psychophysical approach was used to determine the maximum acceptable frequencies of lift for sitting and standing postures at two reach distances. Subjects were trained for six weeks. During the experiment, heart rate, ratings of perceived exertion of the back, shoulder, and arm, and the maximum acceptable frequency of lift were recorded every 15 min for 2 h. Results of this study indicate that subjects, for two hours, can maintain frequency of lifting equivalent to 51% of the maximum frequency acceptable to them for a 4-min period. Although heart rate did stabilize over the 2-h period, ratings of perceived exertion showed continuous increase. Due to training, the maximum acceptable frequency of lift increased on the average by 7.23%. Subjects accepted maximum work rate for a 4.54-kg load. Data were also collected on three females, and these were compared with data from a past study. Differences in the two studies were observed.
Flowcharts Used for Procedural Instructions
Authors: Krohn Gregory S.
Published: July 2017

Two factors in the graphic structure of flowcharts used for a problem-solving task were evaluated, The two factors were the directional orientation of the flowchart and the number of alternatives leading from decision boxes. A third factor evaluated was problem complexity. Eight groups of subjects used variations of binary and multiple-alternative flowcharts or prose written in paragraphs to solve problems. Performance measures were the number of incorrect solutions to problems, the time taken to view the formats, and the time taken to solve problems. Performance was best when the directional orientation of the flowchart was consistent with reading patterns (from left to right and from top to bottom). The number of alternatives leading from decision boxes had no effect on performance.
An Analysis of the Processing Requirements of a Complex Perceptual-Motor Task
Authors: Kramer Arthur F. , Wickens Christopher D. , Donchin Emanuel
Published: July 2017

Current concerns in the assessment of mental workload are discussed, and the event-related brain potential (ERP) is introduced as a promising mental-workload index. Subjects participated in a series of studies in which they were required to perform a target acquisition task while also covertly counting either auditory or visual probes. The effects of several task-difficulty manipulations on the P300 component of the ERP elicited by the counted stimulus probes were investigated. With sufficiently practiced subjects the amplitude of the P300 was found to decrease with increases in task difficulty. The second experiment also provided evidence that the P300 is selectively sensitive to task-relevant attributes. A third experiment demonstrated a convergence in the amplitude of the P300s elicited in the simple and difficult versions of the tracking task. The amplitude of the P300 was also found to covary with the measures of tracking performance. The results of the series of three experiments illustrate the sensitivity of the P300 to the processing requirements of a complex target acquisition task. The findings are discussed in terms of the multidimensional nature of processing resources.
Seat Comfort: A Review of the Construct in the Office Environment
Authors: Lueder Rani Karen
Published: July 2017

A general verview of approaches to the assessment of comfort relevant to design of office furniture is presented. These approaches include physiological/anatomical, subjective, postural, and performance-based measures. Pertinent literature from other fields is included.
Comparison of Abbreviation Methods: Measures of Preference and Decoding Performance
Authors: Rogers William H. , Moeller George
Published: July 2017

Two experiments were conducted to determine the optimal method for abbreviating any specific set of words. Experienced sonar operators rated conventional, nonsystematically produced abbreviations as slightly better than simple truncation abbreviations, and as much better than contraction/vowels-out abbreviations in representing a set of words used on a modern sonar system. In the second experiment, subjects decoded different sets to evaluate the effects of abbreviation method and single versus multiple abbreviations of the same word. During training, when the precise endings of words had to be reported, fewer errors were made in the decoding of conventional abbreviations. During test trials, error rates were comparable, but the speed of decoding of the rule-based abbreviations improved more over trials. These findings are discussed in terms of word-abbreviation similarity and the ability of subjects to apply rule knowledge to aid in practiced decoding. Multiple abbreviations had no detrimental effects on decoding performance. Use of truncation is recommended to minimize costs in selection of abbreviations for new systems.
Time Series Models of Human Factors Dynamics
Authors: Carter Robert C.
Published: July 2017

The past is one of the best predictors of the present and future behavior of individuals or organizations. Few would argue with this principle, yet it is largely ignored in the human factors literature. Most data analysis assumes independence of successive observations, and most theories deal with simultaneous values of several variables. This paper illustrates the dynamics of the two major subjects of human factors studies: organizations and individuals. Several representative human factors variables are shown to exhibit dynamism. Implications of a dynamic viewpoint are that static `heories may be incomplete, traditional data analysis methods are inappropriate for some types of human factors data, experimental designs for dynamic variables will have few subjects and many observations per subject, and dynamic analysis will be useful in human factors.
Reading Moving Text on a CRT Screen
Authors: Granaas Michael M. , McKay Timothy D. , Laham R. Darrell , Hurt Lance D. , Juola James F.
Published: July 2017

Text was presented on a cathode-ray tube screen in a format called "leading," in which the text was moved in discrete jumps of one or more characters at a time from right to left. Experiments 1 and 2 demonstrated that jumps of from 4 to 10 characters at a time produced no significant comprehension differences, but reading comprehension was poorer for jumps of 1 or 2 characters. Experiment 3 showed that reading comprehension in the leading format was significantly inferior to that obtained when text was presented in a standard page format on the CRT screen.
The Use of Secondary Tasks in Adaptive Training
Authors: Johnson David F. , Haygood Robert C.
Published: July 2017

The purpose of this study was to demonstrate the feasibility of conducting adaptive training by adapting primary-task difficulty on the basis of secondary-task performance. Sixteen subjects were adapted on the basis of primary-task performance, and 16 on secondary-task performance. These were matched by 32 fixed-training subjects, who were individually yoked to the adaptive-training subjects. Performance of subjects adapted on primary-task performance was superior to that of subjects adapted on secondary-task performance. However, the results show clearly that adaptation on secondary-task performance is practical and potentially useful. As in most previous studies, adaptive training was superior to fixed training.
Individual and Group Performances as Functions of the Team-Training Load
Authors: Morgan Ben B. , Coates Glynn D. , Kirby Raymond H. , Alluisi Earl A.
Published: July 2017

The effects of team training load on both individual-and group-skill performances and training were measured in the laboratory with 10 five-member teams. Each team consisted of a specific five-member combination drawn from a total of 20 undergraduate volunteer male subjects. During the first 48 h of work, subjects were trained to perform the five individual- and one group-performance tasks presented with the Multiple-Task Performance Battery employed in the synthetic-work approach to performance assessment (see Alluisi, 1964; Chiles, Alluisi, and Adams, 1968; Morgan and Alluisi, 1972). Subsequently, trained subjects were combined in different numbers with untrained subjects to provide teamtraining loads (percentages of untrained team members) ranging from 0 to 100% in 20% steps. The five subjects in each of these teams worked together for 48 h over six consecutive days. Both individual and team performance effectiveness was reduced in direct proportion to the percentage of untrained personnel substituted into a trained team. However, neither the individual performances of the trained personnel nor the skill acquisition rates of the untrained personnel were adversely affected by increasing the team-training load.
Effects of Adjustable Furniture on VDT Users
Authors: Shute Steven J. , Starr Steven J.
Published: July 2017

Telephone operators served as their own controls in two field studies of advanced furniture designed for video display terminal (VDT) workstations. The advanced furniture was characterized by dimensions that were easily adjusted by users, in contrast with conventional furniture that provided either no adjustments or inconvenient adjustments that could only be made with difficulty. An eight-week study focused on advanced VDT tables, and a fiveweek study focused on advanced chairs. Four combinations of advanced and conventional workstation components were compared. Although on-the-job discomfort was reduced when either conventional component was replaced with an advanced component, the effect was far greater when the advanced table and the advanced chair were used together. The adjustments of the advanced furniture were reported to be easy to use, and the advanced furniture was rated more highly than the conventional furniture.
Dexterity Performance and Reduced Ambient Temperature
Authors: Riley Michael W. , Cochran David J.
Published: July 2017

This study examined the dexterity performance of 35 male and 35 female subjects at ambient temperatures of 1.7°C, 12.8°C, and 23.9°C. Subjects wore typical industrial worker apparel without gloves. The Purdue Pegboard, two pencil-point tapping tasks, an assembly task, and a fine manipulative task were used to measure the dexterity performance. Results indicate that after approximately 15 min of exposure there was no difference between performance at 12.8°C and 23.9°C, but there was a difference between performance at 1.7°C and 12.8°C as well as between performance at 1.7°C and 23.9°C. The decrement in performance at 1.7°C ranged from 0.3 to 15.7% when compared with performance at 23.9°C . In five of the 11 performance scores used, a difference due to gender was seen, with the males performing better on an assembly task and the females performing better on single-activity, repetitive tasks. At the higher ambient temperatures (12.8°C and 23.9°C), the average of the minimum finger skin temperature for males was from 0.57°C to 1.2°C higher than for females, whereas at 1.7°C there was no significant difference between the groups for minimum finger skin temperature.
Vigilance and Task Load: In Search of the Inverted U
Authors: Wiener Earl L. , Curry Renwick E. , Faustina Mary Lou
Published: July 2017

The "Inverted-U Hypothesis" states that for a given task, there is an optimal level of workload or demand that yields the highest level of performance. A departure in either direction will result in a monotonically lower performance level, hence an inverted-U-shaped relationship between task demand and quality of performance. Most studies to date have failed to demonstrate the left-hand branch of the curve, that is, the regime in which performance presumably rises as load increases. The purpose of this study was to explore whether lowlevel additional demand on the monitor would result in improved performance.

Four groups of subjects performed a visual monitoring task for 48 min, then two of the four groups were given additional tasks, and a third had potentially distracting information on its display. Results indicated that the two groups with additional demand detected more signals than did the control group or the control-plus-distraction group. There were no significant differences in false alarms.
The Effects of Glare on the Contrast Sensitivity Function
Authors: Finlay David , Wilkinson Jenny
Published: July 2017

Contrast sensitivity functions (CSFs) were measured under conditions of glare and no glare. The spatial frequencies used were 1.7,2.4,3.00, 11.4, and 18.5 cycles/deg. The CSFs obtained showed greatest sensitivity around 3.00 cycles/deg for both glare and no-glare conditions. Generally, glare reduced sensitivity over all frequencies tested.
A Field Trial of Attention and Search Conspicuity
Authors: Cole Barry L. , Hughes Philip K.
Published: July 2017

Conspicuity might be defined as the property of an object that causes it to attract attention or to be readily located by search. It is often regarded as an attribute of the target object, but the state of attention of the observer is a factor that cannot be ignored. In this paper we define two kinds of conspicuity, attention conspicuity and search conspicuity. Attention conspicuity refers to the capacity of the object to attract attention when it is unexpected. Search conspicuity is the property of the object that enables it to be quickly and reliably located by search. A field trial was conducted to provide measures of these two kinds of conspicuity. Two groups of subjects were required to drive along a defined route on which disc targets were placed; one group was simply asked to report what attracted attention and the other was to search for and report the disc targets. The frequency with which the discs were reported was taken as a measure of conspicuity. The two kinds of conspicuity were found to be related in a systematic way. It was found that conspicuity was not strongly dependent on either object reflectance or size. An important determinant was the angle at which the object was displaced away from the line of sight.
The Effect of Redundant Cues on Retrieval Time
Authors: Simon J. Richard , Overmeyer Scott P.
Published: July 2017

This experiment was concerned with determining the effect of redundant shape and color cues on retrieval time. Subjects saw a pair of stimuli presented sequentially on a screen and pressed one of two keys to indicate whether the second stimulus was the same as or different from the first. Stimuli for the color coding group differed only in terms of color (i.e., red, green, or yellow). Stimuli for the shape coding group differed only in terms of shape (i.e., circles, squares, or triangles). Stimuli for the redundant coding group were red, green, or yellow circles, squares, or triangles, with each shape having its own distinctive color. There was no clear-cut evidence that redundant coding facilitated retrieval of information from short-term memory. The redundant coding group (409 ms) was significantly faster than the color coding group (540 ms), but was not significantly faster than the shape coding group (456 ms). The difference between the shape and color coding groups was not significant. Same responses were significantly faster than different responses (449 versus 487 ms).
Revising Documents with Text Editors, Handwriting-Recognition Systems, and Speech-Recognition Systems
Authors: Gould John D. , Alfaro Lizette
Published: July 2017

Twelve participants were given marked-up manuscripts to edit. Results showed that editing was done much faster (50% and 90%) with a simulated handwriting-recognition system and with a simulated speech-recognition system than with a full-screen text editor (Xedit) that participants had experience in using. With the text editor, participants spent considerable time deciding how to locate a revision on the screen, locating it on the screen, and sometimes rereading the document. These behaviors were not necessary with the simulated handwriting and speech systems, in large part because of differences in external feedback provided by the systems. Handwriting-recognition and speech-recognition systems, in addition to being useful principal-support workstations (as each is often envisioned), may also form the bases for potentially good text editors for typists and secretaries.
Error Correction during Text Entry with Word-Processing Systems
Authors: Neal Alan S. , Emmons William H.
Published: July 2017

To answer questions related to keying errors and error corrections, performance data were collected from typists as they keyed text into a simulated word-processing system. Data are presented on the frequency of error detection, the amount of time spent correcting errors, the number of characters erased per error correction, and the types of errors corrected. Comparisons are also made between corrected and uncorrected errors.
Effects of Experience on Learning, Using, and Evaluating a Text Editor
Authors: Rosson Mary Beth
Published: July 2017

Routine users of a text editor at a research lab were surveyed about their experiences in learning and using the editor and were asked to describe their likes, dislikes, and suggestions for additions to the system. The 121 users responding to the survey represented samples from three user classes-secretaries, nonprogrammer research members,' and programmers-and they varied considerably in their experience both with the editor in question and with other text editors. Experience with the system itself predicted a number of survey measures, such as the customization of programmable function keys, the extension of the editor through macros, and the number and type of additions suggested. However, strong effects of both work type and prior experience with other editors were observed, even for users who were very experienced with the system.
Artificial Intelligence
Authors: Hillman Donald J.
Published: July 2017

Artificial intelligence (AI) is concerned with the symbol-manipulation processes that produce intelligent action; that is, acts that are arrived at by intelligible reasoning steps that are guided by knowledge of a particular domain. AI areas relevant to human factors and automation include expert systems, natural-language understanding, and intelligent robotics. These topics are reviewed and illustrated. Potential contributions of human factors research to AI are briefly described.
The Allocation of Functions in Systems
Authors: Price Harold E.
Published: July 2017

A systematic approach for allocating functions to humans and machines has been an elusive goal of human factors specialists for more than 30 years. The author has fortunately been able to obtain contract support for reviewing the earlier techniques and methods in the literature and deriving “lessons learned” to guide the development of the approach reported here. The approach is believed to be systematic and embedded in the overall system design process. This paper describes the systems approach to design and how the allocation of functions is a part of it, as a five-step procedure with four principal rules for arriving at a hypothetical allocation.
Supervisory Control of a Flexible Manufacturing System
Authors: Sharit Joseph
Published: July 2017

This paper describes a study that explored human capabilities in supervisory control of a flexible manufacturing system (FMS). Implications of current design strategies concerning the human supervisory role in FMSs are discussed. Also examined are issues in human supervisory control that arise from features characteristic of these types of automated systems. A real-time interactive simulation methodology is described that served as the basis for evaluating human performance. Results are explained in terms of two frameworks: (1) one that incorporated hypothetical dimensions of the mental workload construct into various task conditions; and (2) a simple decision-making model intrinsic to which was the imposition on the human of a relatively well-defined locus of control. The effectiveness of graphics was evaluated as a decision-support device aimed at enhancing human pattern-recognition capabilities.
Beyond the Sterile Cockpit
Authors: Wiener Earl L.
Published: July 2017

The rapid advance of cockpit automation, enabled by microprocessor technology and motivated by the quest for safer and more efficient flight, has both its supporters and its detractors. Even the supporters tend to view the march toward computer-directed flight as a mixed blessing. Certain dramatic accidents and incidents in recent years, as well as the destruction of Korean Airlines Flight 007, have been interpreted by many as automation induced. Many of the critics outside of the aviation community, journalists, and the general public, have harped on the negative side of flight-deck automation without recognizing its positive aspects. The author advances the view that the time-honored recommendation that humans should serve as monitors of automatic devices must be reconsidered, and that the human must be brought back into a more active role in the control loop, aided by decision support systems.
System Design for Speech Recognition and Generation
Authors: Simpson Carol A. , Mccauley Michael E. , Roland Ellen F. , Ruth John C. , Williges Beverly H.
Published: July 2017

This article reviews human factors research on the design of systems that use speech recognition for human control of the system or that use speech generation for the display of information. Speech technology terms are defined and the current status of the field is reviewed. Included are the performance of current speech recognition and generation algorithms, descriptions of several applications of the technology to particular tasks, and a discussion of research on design principles for speech interfaces. Finally, directions for further research are suggested. The need for better simulation techniques and performance measures is stressed, as is the importance of considering the entire system in which speech technology will function.
Effect of Glare on Performance of a VDT Reading-Comprehension Task
Authors: Garciai Kathy Dugas , Wierwille Walter W.
Published: July 2017

This study was undertaken to determine whether objective measures of reading performance are affected by short exposure to text on a display when glare is present. Reading performance was assessed using reading time and correctness of answers as measures. In a preliminary experiment 20 reading passages were ranked according to subjective reading difficulty and also according to an objective measure. Subsequently, in the main experiment subjects read the 20 passages presented on a VDT under both no-glare and glare conditions. When task difficulty was measured by subjective ranking, glare was found to increase the amount of time required to read relatively easy passages and to decrease the amount of time required to read relatively difficult passages. Other findings included a general increase in reading time and a decrease in the proportion of correct answers with increases in task difficulty for both subjective and objective ranking of difficulty.
Underlying Behavioral Parameters of the Operation of Touch-Input Devices: Biases, Models, and Feedback
Authors: Beringer Dennis B. , Peterson James G.
Published: July 2017

Touch-entry devices have exhibited a number of advantages in relatively low-resolution applications. Requirements for high-resolution input must, however, take into account the inherent biases and limitations of the operator. In this study performance biases in the use of an infrared touch-input device were examined with the input (display) surface at various declinations. A general bias to touch low and to the right of targets was found, the low bias increasing with increasing display declination. Attempts to reduce bias error through simple models based upon earlier trials were more effective when derived from individual performances rather than populational behavior (averages). Handedness effects on performance were also found. Training is discussed as a viable alternative, along with preliminary training results.
Individual Differences in Information-Processing Ability as a Predictor of Motor Vehicle Accidents
Authors: Avolio Bruce J. , Kroeck K. Galen , Panek Paul E.
Published: July 2017

The objectives of this investigation were two-fold: to replicate and extend prior research that has provided evidence to support the use of information-processing measures as potential indices for predicting motor vehicle accident involvement and to test a newly developed measure of visual selective attention for predicting accident involvement. Seventy-two drivers (aged from 28 to 59) were tested on three measures of information processing. In accordance with prior research, performance on two measures of selective attention was significantly correlated with individual accident rates. Information-processing measures are discussed with regard to their possible use in the prediction of motor vehicle accidents.
The Effects of Syntactic Complexity on the Human-Computer Interaction
Authors: Chechile Richard A. , Fleischman Rebecca N. , Sadoski Darleen M.
Published: July 2017

Three divided-attention experiments were performed to evaluate the effectiveness of a syntactic analysis of the primary task of editing flight route-way-point information. For all editing conditions, a formal syntactic expression was developed for the operator's interaction with the computer. In terms of the syntactic expression, four measures of syntactic complexity were examined. Increased syntactic complexity did increase the time to train operators, but once the operators were trained, syntactic complexity did not influence the divided-attention performance. However, the number of memory retrievals required of the operator significantly accounted for the variation in the accuracy, workload, and task completion time found on the different editing tasks under attention-sharing conditions.
Intermittent Illumination from Visual Display Units and Fluorescent Lighting Affects Movements of the Eyes Across Text
Authors: Wilkins Arnold
Published: July 2017

The size of eye movements across text was measured under conditions in which the text was illuminated by fluorescent light or was displayed on the screen of a cathode-ray tube. Under these conditions of intermittent illumination the high-velocity saccadic eye movements were enlarged. The extent to which they were enlarged depended on the frequency of intermittency, but was generally equivalent to the width of one letter. This disturbance of ocular motor control by intermittent illumination might help to explain why reading is generally slower on computer display terminals than with printed text.
Perception-Response Time to Unexpected Roadway Hazards
Authors: Olson Paul L. , Sivak Michael
Published: July 2017

Perception-response (PR) time, the time from the first sighting of an obstacle until the driver applies the brakes, is an important component of stopping sight distance. The purpose of this study was to measure the PR time of unalerted subjects to an obstacle in their lane encountered while cresting a hill. Data were obtained from 64 subjects, of whom 49 were young and 15 older. Measures were made of the time from first sighting of the obstacle until the accelerator was released, as well as accelerator-to-brake time. The results indicate a 95th percentile PR time of about 1.6 s for both age groups.
Readability of Computer-Generated Fill-Justified Text
Authors: Trollip Stanley R. , Sales Gregory
Published: July 2017

This paper describes two studies designed to explore the effects of reading fill-justified text on reading speed and comprehension. A common contemporary practice is to use the power of microcomputer-based processors to produce printed material that is fill justified(i.e., both left and right margins are straight). Fill justification is frequently accomplished by inserting varying numbers of extra spaces between words. Both studies compared the reading speed of two groups, one that read a fill-justified passage and the other that read the same passage printed with a ragged right margin. Comprehension was investigated in the one study by comparing performance on a test made up of recognition questions; in the other, performance was compared on recall questions. Results indicate significant increase in reading time (that is, slower reading speed) for groups reading fill-justified text. No differences in comprehension were detected.
A Profile of Drivers' Map-Reading Abilities
Authors: Streeter Lynn A. , Vitello Diane
Published: July 2017

To create better aids for everyday surface navigation, people's navigational preferences, habits, experiences, abilities, and route-selection strategies were examined. Self-described good navigators like and use maps, and they differentially value landmarks, such as rivers, railroads, and houses, whereas poor navigators tend not to use maps, prefer verbal instructions, and tend to rate all landmarks as equally valuable for route finding. Routes selected by people with varying degrees of familiarity with an area were compared with routes generated by standard graph-search procedures. A shortest-path, breadth-first route characterized half of the "expert" routes, whereas none of the graph-search procedures matched "intermediate" and "novice" routes. A good predictor of whether people chose a particular road was whether the sum of A + B + C (where A equals the straight-line distance from the start to the road, B equals the distance traveled on the road, and C equals the straight-line distance from the departure point on the road to the destination) did not exceed the straight-line distance between start and destination by more than about 20%.
Movement Time and Brake Pedal Placement
Authors: Morrison Ronald W. , Swope J Geoffrey , Halcomb Charles G.
Published: July 2017

Optimum relocation of the brake relative to the accelerator can reduce stopping distance and may mean the difference between an accident and a near-accident. A driving simulator was used to examine efficiency of braking movement time. Movement times were measured for 60 participants (30 male, 30 female) in six different depth/lateral-separation conditions. Movement times were shown to improve as a result of moving the brake pedal from its typical heights above the accelerator to positions equal with and below the accelerator.
The Effects of Handle Shape and Size on Exerted Forces
Authors: Cochran David J. , Riley Michael W.
Published: July 2017

This research empirically evaluated the effects of handle shape and size on the hand's ability to resist or exert force in six directions. Thirty-six handles of four sizes and nine shapes were tested for maximum force exertion by male and female subjects. The results show that subjects were able to generate higher forces with different sizes and shapes of handles, depending upon the direction of force exertion. This suggests that handles that are associated with high forces on particular directional tests are probably suited for tasks that incorporate that particular type of force or movement; they may not be appropriate for other tasks that do not incorporate such movement.
An Evaluation of Tool Design and Method of Use of Railroad Leverage Tools on Back Stress and Tool Performance
Authors: Rockwel Thomas H. , Marras William S.
Published: July 2017

The effects of railroad claw bar design factors and method of use upon performance and back stress were investigated. Novice and experienced subjects were tested for their ability to use the claw bar to remove track spikes. Two standard claw bar designs were evaluated. The method of tool use was described by body position relative to the claw bar and by body action.

Tool design had no significant effect on either tool-lifting performance or back-stress measures. Body action patterns, but not body position, were found to have significant effects on both performance and back stress. Results support the use of a body action involving the use of the arms only. This method provides the required impulse forces with minimum back stress and also provides proper balance to avoid falls from sudden spike removal.

Proper technique, as opposed to total force application, was found to be the key factor in tool use. Novices attempt to apply a large, sustained force using the whole body, whereas experienced trackmen use a snapping action to generate the required forces. Trackmen generated 50% more lifting force than did the novices.
Repetitive Trauma Disorders: Job Evaluation and Design
Authors: Armstrong Thomas J. , Radwin Robert G. , Hansen Doan J. , Kennedy Kenneth W.
Published: July 2017

Repetitive trauma disorders of the upper extremity are a major cause of lost work in many hand-intensive industries. Reported risk factors include repetitive and forceful exertions, certain postures, mechanical stress, low temperatures, gloves, and vibration. Risk factors can be identified with job analysis procedures based on traditional work-methods analysis. Risk factors can be controlled through reallocation of work, balancing of tools, selection of alternative tool designs, work relocation, selection of suitable hand protection, and elimination of hand exposure to low temperatures and vibration. Drawing-board manikins are used with computer-aided design systems to estimate the best work location for a given task.
Integrated Flight Training
Authors: Childs Jerry M.
Published: July 2017

The concept of integrated flight training introduces pilot trainees to flight instrument cues early in training and emphasizes the association of those cues with out-the-window “contact” cues. The integrated flight training literature is reviewed separately for civil and military aviation. Conclusions are summarized concerning the potential effect of integrated flight training Oil aviation safety.
No Effect of Noise on Vigilance Performance?
Authors: Koelega Harry S. , Brinkman Jan-Albert , Bergman Hans
Published: July 2017

The effects of intermittent noise and its temporal pattern on visual vigilance performance were investigated using a between-subjects design with a multivariate approach. The conventional way of analyzing the data showed a decrement in sensitivity (A′) with time on task, a rise in false alarms, but no significant effect of noise. However, a detailed analysis demonstrated a facilitatory effect of the noise stimuli, which may be explained in terms of orienting reaction theory. It is suggested that the usual way of analyzing data from vigilance experiments may veil the effects of independent variables, such as noise. Some sex differences in performance were also noted. An additional estimation task provided no support for expectancy theory.
A Simultaneous Regression Model for Double Stimulation Tasks
Authors: Aykin Nuray , Czaja Sara J. , Drury Colin G.
Published: July 2017

Reaction time in double stimulation tasks was investigated, and a simultaneous regression model was proposed within the concept of variable capacity allocation theory. The model was tested using a double stimulation task paradigm. In the experiment, six levels of inter-stimulus interval (ISI) and three levels of stimulus complexity were employed. The regression analysis showed that the effects of stimulus complexity and ISI were significant. From the simultaneous regression model, reaction times to the first and to the second stimulus were predicted for the different experimental conditions.
Estimating Reliability with Small Samples: Increased Precision with Averaged Correlations.
Authors: Dunlap William P. , Silver N. Clayton , Bittner Alvah C.
Published: July 2017

Both analytic and Monte Carlo methods were used to show that empirical estimates of the standard error of an averaged correlation agree quite well with theoretical expressions derived from Pearson's asymptotic equations. Where discrepancies did exist, particularly with small sample sizes, the theoretical formula slightly overestimated the actual (empirical) standard error, thus making a test of significance conservative. It was shown that by testing repeatedly with a small sample and averaging the resulting relations, one may obtain precision equivalent to single estimates from much larger samples. Furthermore, the greatest increase in precision occurred when the population correlation was small, the situation where greatest precision is needed. These results should prove of value for human factors evaluations, which often have limited subject resources.