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Biomedical subjects

G Salvendy

Publications and source records attributed to G Salvendy.

At least 19 recordsLinked to original sources
PubMed2001

Ergonomics of electronic mail address systems: related literature review and survey of users.

The paper reviews the cognitive ergonomics literature related to electronic mail (e-mail) address design. Based on this information, a survey of 160 users of current e-mail address system was conducted. The aim was to obtain information on likes, dislikes and difficulties associated with e-mail address and to obtain users' suggestions and input for improving the current e-mail address system. The survey results indicated that users want an improved e-mail address system with regard to shorter length, useful information and appropriate presentation of information.

Computer Communication Networks↗
PubMed2001

Ergonomics guidelines for designing electronic mail addresses.

The aim was to design a human-centred electronic mail (e-mail) address system based on networking technology and cognitive ergonomics. Based on the background literature and the results of users' survey, a conceptual model is developed for designing e-mail addresses. This model consists of e-mail address components of formats, domain length, meaningfulness, orientation and information type pertaining to recall, information association and categorization. Five hypotheses were proposed to test the conceptual model, and four experiments were conducted with 85 participants to test the hypotheses. The dependent variables were performance time, error rate and degree of satisfaction, and the independent variables were components of the e-mail addresses. The main results indicate that for a recall task, significantly lower total performance time (26.2%) and error rate (75%) were found for the hybrid formats (digits and letters) than for the letter format, and up to four characters was the best single domain length. For an information association task, embedding both geographical and organizational information significantly decreased the response time (10.9%) in comparison with only embedding organizational information. For a categorization task, embedding both geographical information and organizational information significantly decreased response time (40.7%) in comparison with only embedding organizational information. This research demonstrates the importance of human-centred design and provides guidelines in effectively designing e-mail addresses.

Computer Communication Networks↗
PubMed2000

Measuring consistency of web page design and its effects on performance and satisfaction.

This study examines the methods for measuring the consistency levels of web pages and the effect of consistency on the performance and satisfaction of the world-wide web (WWW) user. For clarification, a home page is referred to as a single page that is the default page of a web site on the WWW. A web page refers to a single screen that indicates a specific address on the WWW. This study has tested a series of web pages that were mostly hyperlinked. Therefore, the term 'web page' has been adopted for the nomenclature while referring to the objects of which the features were tested. It was hypothesized that participants would perform better and be more satisfied using web pages that have consistent rather than inconsistent interface design; that the overall consistency level of an interface design would significantly correlate with the three elements of consistency, physical, communicational and conceptual consistency; and that physical and communicational consistencies would interact with each other. The hypotheses were tested in a four-group, between-subject design, with 10 participants in each group. The results partially support the hypothesis regarding error rate, but not regarding satisfaction and performance time. The results also support the hypothesis that each of the three elements of consistency significantly contribute to the overall consistency of a web page, and that physical and communicational consistencies interact with each other, while conceptual consistency does not interact with them.

Adult↗
PubMed1998

Predictive models of carpal tunnel syndrome causation among VDT operators.

Carpal tunnel syndrome (CTS), a cumulative trauma disorder of the hand and wrist, is one of the most common disabling injuries experienced by video-display terminal (VDT) operators. The purpose of this study was to develop a theoretically based operational quantitative predictive model of the risk of work-related CTS among VDT operators. A total of 100 female VDT operators, who performed a variety of office functions, were studied at a major midwestern university. Data were collected on job exposure, anthropometry and posture factors using questionnaires, direct observation and video-recording. Discriminant analysis and logistic regression were performed to develop the operational models. The results of the study indicated the following: (1) percentage of workday working with a VDT was the most significant factor and accounted for 60% of the variance explaining the causation of musculoskeletal discomforts associated with CTS; (2) discriminant function with six variables (i.e. work duration, trunk incline, wrist extension, wrist ulnar deviation, overall anthropometric measure, weighted anthropometric measure) correctly classified 73% of the CTS group and 72% of the non-CTS group; (3) using the logistic regression model, the probabilities associated with changes in the predictive variables as affecting CTS risk are presented such that increasing the daily work duration from 1 h to 4 h increases the probability of CTS risk from 0.45 to 0.92. The results of the study suggest that the main causation of CTS is job design, the secondary (and lesser cause) is posture associated with the workplace design and the least contributing factor to CTS causation is the individual's anthropometric make-up.

Analysis of Variance↗
PubMed1998

Aftereffects and sense of presence in virtual environments: formulation of a research and development agenda.

This report represents a committee summary of the current state of knowledge regarding aftereffects and sense of presence in virtual environments (VEs). The work presented in this article, and the proposed research agenda, are the result of a special session that was set up in the framework of the Seventh International Conference on Human Computer Interaction. Recommendations were made by the committee regarding research needs in aftereffects and sense of presence, and, where possible, priorities were suggested. The research needs were structured in terms of the short, medium, and long term and, if followed, should lead toward the effective use of VE technology. The 2 most critical research issues identified were (a) standardization and use of measurement approaches for aftereffects and (b) identification and prioritization of sensorimotor discordances that drive aftereffects. Identification of aftereffects countermeasures (i.e., techniques to assist users in readily transitioning between the real and virtual worlds), reduction of system response latencies, and improvements in tracking technology were also thought to be of critical importance.

Adaptation, Physiological↗
PubMed1996

Expert-novice knowledge of computer programming at different levels of abstraction.

Computer programming knowledge can be classified into five levels of abstraction: objective, conceptual, functional, logical, and physical. An experiment was carried out to determine whether the mastering of knowledge at different levels of abstraction changed with the level of skill. Ten experts and ten novices in C computer programming participated in the experiment. The subjects' knowledge at the five levels of abstraction was tested through 20 multiple-choice questions. The experimental results indicated that knowledge differences between experts and novices at an abstract level or a concrete level depended on what abstract or concrete knowledge was implied. Experts had better abstract knowledge than novices at the conceptual and functional levels but not at the objective level. Experts had better concrete knowledge than novices at the physical level but not at the logical level. The classification of computer programming knowledge in levels of abstraction and the experimental results helped in clarifying a general finding from previous studies that experts had better abstract knowledge than novices.

Cognition↗
PubMed1995

Information visualization; assisting low spatial individuals with information access tasks through the use of visual mediators.

This study investigated the use of visual mediators to facilitate information access by low spatial individuals. Based on theories of adaptive learning and field-dependence, two human-computer interfaces were developed which were intended to compensate for the inability of low spatial individuals to readily construct visual mental models of a menu system's structure. The two compensatory interfaces included: a 2D visual hierarchy and a linear structure. The information search performance of high and low spatial individuals was compared on the two compensatory interfaces and a third challenge match interface, which challenged individuals to construct a mental model of a hierarchical menu system in order to perform efficiently. The visual mediators were successful in accommodating low spatial individuals, as indicated by the lack of any significant performance differences being detected between the high and low spatial groups on the two compensatory interfaces. High spatial individuals outperformed low spatial individuals only when information search tasks required the use of spatial ability in mentally constructing a model of the organization and structure of embedded task information. The key factor in the accommodation process was the elimination of the need to mentally visualize the structure of embedded task information. These results indicate that visualization techniques can be successfully used to enhance the information search performance of low spatial individuals.

Adolescent↗
PubMed1994

Effects of diversity in cognitive restructuring skills on human-computer performance.

The objective of this study was to determine if more efficient performance in hierarchical computer environments could be obtained from field-dependent (low technical aptitude) individuals by manipulating information structuring requirements. A three-dimensional (task complexity, quality of integration, and level of differentiation) conceptual model was proposed to explain differences in memory organization which were suggested to lead to computer performance differences. The model was tested with 36 subjects, 18 identified as field-dependent and 18 as field-independent. The subjects performed the information search task under three task conditions, two structured by the experimenter and one by the subjects. The results indicated that the effects of differences in the organization of task information on computer performance time can be controlled for by providing subjects with a period of time dedicated to the acquisition of a system's structure.

Adolescent↗
PubMed1994

The effects of computer interface design on human postural dynamics.

The main objective of this study was to examine the effects of human-computer interface design on postural dynamics, i.e., changes in working postures and postural discomfort exhibited by operators of the computer-based remote bar coding (RBC) system. In addition, the effects of different work/rest schedules on postural dynamics were evaluated. Twelve subjects participated in the laboratory experiment, which consisted of twelve scenarios utilizing two cognitive task requirement factors, i.e., (1) information presentation mode, defined through the letter image preview on the computer screen (none or one preview image); and (2) the information processing mode, defined through the specific keying method (key all characters or key 5 digits only). The third experimental factor was the work/rest schedule (50 min work/10 min break, 2 h of work/15 min break, or flexible schedule). The results showed that requirements of human-computer interface design significantly affected the operators' postural dynamics. It was concluded that not only the physical, organizational, or psychosocial work environment characteristics, but also the cognitive task characteristics are important for assessment of postural effects in the VDT work. The relationship between interface design, mental workload and postural dynamics should be carefully considered in future studies aimed at optimizing the human-computer data entry tasks.

Adult↗
PubMed1991

Effects of respirators on performance of physical, psychomotor and cognitive tasks.

Possible work decrements caused by respirator usage were examined. A battery of physical, psychomotor and cognitive tasks was used to investigate the effects of respirator wear on 12 subjects. A repeated measures experimental design was used to study the effects of three types of respirators: a disposable dust mask; an air purifying half-mask; and a full-face airline mask. Performance while wearing a mask was compared to the control condition without a respirator. The results from the physical work task of riding a bicycle ergometer indicated approximately a 10% increase in oxygen consumption when subjects wore half and full-face masks in comparison to when they performed the tasks without a mask. The results indicate that wearing the respirators did not have a significant effect on the performance of cognitive tasks but did affect significantly the performance of psychomotor tasks such as steadiness of work performance and movements requiring accurate control for positioning of objects.

Adult↗
PubMed1989

Microbreak length, performance, and stress in a data entry task.

The effects of brief rest pauses on performance and well-being were evaluated for a highly repetitive, data entry task. Experienced data entry operators (N = 20) performed the task in a two-day experiment in a simulated office environment. Each day was divided into six, 40-min work periods. Subjects took a brief rest pause at the workstation (microbreak) in the middle of each work period. Subjects were instructed to terminate this microbreak when ready to resume work. Keystroke rate, error rate, correction rate, heart rate and heart rate variability were scored for each half of the work period. In addition, mood states before and during the work period were assessed. Microbreaks were found to average 27.4 s in duration. High ratings of fatigue and boredom during the work period were associated with longer microbreaks, suggesting that the break period was self-adjusted relative to mood state. In addition, correction rate and heart rate were lower following long microbreaks, implying that the degree of recovery was linked to the length of the microbreak. Comparison of keystroke output and correction rate before and after the microbreak, however, revealed that performance worsened after the microbreak, suggesting that subjects terminated microbreaks before complete recovery could occur.

Adolescent↗
PubMed1987

Discriminating the structure of rotated three-dimensional figures.

Visualizing the structure of transformed (by rotation) three-dimensional (3-D) figures is an important aspect of information processing for computer-graphics tasks. However, little research exists to establish the speed and accuracy in which subjects perform discrimination tasks for transformed images and the effects of rotation variables on perceiving transformed images. This research tests the effects of figural complexity, angles and axes of rotation on the speed and accuracy in which subjects discriminate the structure of rotated 3-D wireframe images. Results show that response times are affected more by angles than axes of rotation, the specific form of the image affects error rates, and the number of 90 degrees bends which determine the structure of an image may be an inadequate measure of form complexity for the task described here.

Cues↗
PubMed1984

Non-work-related movements in machine-paced and self-paced work: an industrial study.

Non-work related movements (NWRM) of 10 experienced industrial workers performing light repetitive work were observed under a variety of conditions. More NWRM were observed for (1) machine-paced versus self-paced operations; and (2) a task with high mental load versus one with a low mental load. In addition, the age of the worker was found to be negatively correlated with NWRM.

Journal Article↗
PubMed1983

A case study of the occupational stress implications of working with two different actuation/safety devices.

A case study was conducted using an automatic sphygmomanometer to compare the stress encountered by workers using two different machine actuation/safety devices. The experiment took place in a small metal stamping plant as part of a government authorized comparison of the devices. Six experienced female workers separately performed the same task on the same power presses using either a photo electronic or a two-hand button device. These two devices perform dual duty as both machine actuators and machine safeguards. Blood pressure at the ankle and heart rate were measured periodically and a questionnaire was administered. The case study approach to this experiment was necessitated by government restrictions which limit the population of workers experienced with both devices. The results of the case study are twofold: (1) For the small population tested no significant difference was found in the stress measures examined for machine operators; and (2) A feasible in-plant methodology is demonstrated for unobtrusively monitoring worker populations exposed to machine related stress.

Journal Article↗
PubMed1982

Impact of personality and intelligence on job satisfaction of assembly line and bench work - an industrial study.

A study of the impact of machine-paced (M/P) and self-paced (S/P) work on job satisfaction of 28 female industrial assembly workers was evaluated in which M/P work was confounded with simplified work and the S/P job was confounded with enriched tasks. Results indicated the following: 1. Over three-quarters of workers were more satisfied in S/P jobs, while only less than one-quarter were more satisfied in M/P jobs. 2. The 16PF personality test effectively predicts (0.88 multiple correlation) the satisfaction ratios of M/P to S/P jobs.

Journal Article↗