Task frequency as a function of age for the powerline technician trade

It is traditionally believed that worker productivity declines with age. The greatest contributor to this stereotype, particularly in physically demanding jobs, is that older workers can no longer maintain their sustained level of work due to the age-associated decline in physical capacity. The objective of this study was to determine the change in the frequency of task performance as a function of age in the power line technician (PLT) trade. The task requirements of the PLT occupation were determined through the use of a detailed job demands analysis (JDA) and the frequency at which these tasks were performed was acquired through a survey derived from the JDA. The results of the survey were assessed as a function of age. Older lineworkers (? 50 years) were found to spend more time working on the ground whereas the younger PLTs (? 39 years) more frequently performed the climbing tasks and the corresponding work on the poles and towers. In contrast the older PLTs performed all pushing/pulling tasks at a greater or equal frequency to that of the younger lineworkers. Despite these differences the frequency of task performance is similar across the age groups studied.     

Changes in physical capacity as a function of age in heavy manual work

The objective of this study was to assess the changes in the physical capacity as a function of age in power line technicians (PLTs). The physical test was designed to closely represent the essential physical tasks of the occupation that were identified through a detailed job demand analysis. The results from the physical test showed that six out of nine test variables did not demonstrate a statistical difference between the mean scores of young (< or = 39 years) and old age (50+ years) groups. However the older group scored significantly lower in the aerobic capacity test, one-handed pull down, and both right and left standard handgrip tests. Despite these differences the older PLT appears to meet and exceed the physical requirements necessary to carry out the essential tasks of this trade. However a physical test with a high level of content and construct validity is necessary to accurately evaluate the workers physical capacity in relation to the job demands. Based on the principal of specificity for muscle training and testing, this study has demonstrated that heavy manual work appears to maintain physical capacity specific to the task as age progresses.     

Changes in physical capacity as a function of age in heavy manual work

The objective of this study was to assess the changes in the physical capacity as a function of age in power line technicians (PLTs). The physical test was designed to closely represent the essential physical tasks of the occupation that were identified through a detailed job demand analysis. The results from the physical test showed that six out of nine test variables did not demonstrate a statistical difference between the mean scores of young (? 39 years) and old age (50 + years) groups. However the older group scored significantly lower in the aerobic capacity test, one-handed pull down, and both right and left standard handgrip tests. Despite these differences the older PLT appears to meet and exceed the physical requirements necessary to carry out the essential tasks of this trade. However a physical test with a high level of content and construct validity is necessary to accurately evaluate the workers physical capacity in relation to the job demands. Based on the principal of specificity for muscle training and testing, this study has demonstrated that heavy manual work appears to maintain physical capacity specific to the task as age progresses.     

Touch a screen or turn a knob: choosing the best device for the job

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

Understanding sources of user variability in computer-based data entry performance

The pervasive use of computers in work settings implies that an increased number of workers, with varying levels of skills and abilities, will be performing computerbased tasks. This study investigated the impact of age, cognitive abilities, and computer experience on the performance of a real world data entry task. One hundred and ten subjects, ranging in age from 20 - 75 years, performed the task for nine hours following task training. The results indicated that abilities such as visuo-spatial skills, motor skills and processing speed had a significant impact on performance as did age and prior computer experience. With respect to age, the older participants completed less work than the younger and middle-aged subjects. Age differences in psychomotor skills and processing speed appeared to be important factors underlying age effects. In fact, the data indicated that after controlling for differences in these abilities age was no longer a significant predictor of work output. Further, after controlling for differences in work output the older people made fewer errors than the younger people. Overall the data suggest that older people will be at a disadvantage in the performance of computer-based data entry work to the extent to which speed of responding is emphasized. However, if speed of responding is not a critical element of performance they will be able to achieve comparable levels of performance to that of younger people.     

Understanding sources of user variability in computer-based data entry performance

The pervasive use of computers in work settings implies that an increased number of workers, with varying levels of skills and abilities, will be performing computerbased tasks. This study investigated the impact of age, cognitive abilities, and computer experience on the performance of a real world data entry task. One hundred and ten subjects, ranging in age from 20 - 75 years, performed the task for nine hours following task training. The results indicated that abilities such as visuo-spatial skills, motor skills and processing speed had a significant impact on performance as did age and prior computer experience. With respect to age, the older participants completed less work than the younger and middle-aged subjects. Age differences in psychomotor skills and processing speed appeared to be important factors underlying age effects. In fact, the data indicated that after controlling for differences in these abilities age was no longer a significant predictor of work output. Further, after controlling for differences in work output the older people made fewer errors than the younger people. Overall the data suggest that older people will be at a disadvantage in the performance of computer-based data entry work to the extent to which speed of responding is emphasized. However, if speed of responding is not a critical element of performance they will be able to achieve comparable levels of performance to that of younger people.     

Input devices for web browsing: age and hand effects

The work reported in this paper examined performance on a mixed pointing and data entry task using direct and indirect positioning devices for younger, middle-aged, and older adults (n=72) who were experienced mouse users. Participants used both preferred and non-preferred hands to perform an item selection and text entry task simulating a typical web page interaction. Older adults performed more slowly than middle-aged adults who in turn performed more slowly than young adults. Performance efficiency was superior with the mouse for older adults only on the first two trial blocks. Thereafter mouse and light pen yielded equivalent performance. For other age groups, mouse and light pen were equivalent at all points of practice. Contrary to prior research revealing superior performance with a light pen for pure pointing tasks, these results suggest that older adults may initially perform worse with a light pen than a mouse for mixed tasks.     

Assessing design features of virtual keyboards for text entry

OBJECTIVE: The present research examined design of a virtual keyboard for text entry with a rotary controller, emphasizing users who differ in age and system experience. BACKGROUND: Existing research has minimally addressed usage frequency, age, and the effects of display shape and letter arrangement on movement and visual search components of text entry tasks. The present research was conducted to close these gaps. METHOD: Two experiments were completed to examine younger (18-28 years) and older (60-75 years) adults' movement and visual search capabilities using four keyboard shapes and three keyboard arrangements. In a third experiment examining combined effects on shape design, 32 younger (18-28 years) and 32 older (60-75 years) adults entered words on the two best shapes from the first experiments. RESULTS: For the movement task, movement time was lowest for shapes with higher shape-controller compatibility. For the visual search task, search time and accuracy were best on the alphabetic arrangement. In the combined task, shape did not significantly influence performance at different levels of practice. Transfers, however, suggested that the shape with salient visual features elicited a text entry strategy for older adults that may promote more consistent performance under occasional usage. CONCLUSION: The studies together demonstrate that keyboard shape is important for efficient performance. Shape-controller compatibility facilitated performance in both age groups. Salient features facilitate performance, especially for older adults. In nearly all cases alphabetic arrangement yielded the best performance. APPLICATION: Recommendations are provided for virtual keyboard design for different usage frequencies, contexts, and users.     

Comparative study of the effects of auditory, visual and multimodality displays on drivers' performance in advanced traveller information systems

A simulator study was conducted to compare 16 younger (mean age 22 years) and 16 older (mean age 68 years) drivers' ratings of workload (time, visual, psychological stress) and performance of navigation and button-pushing (identification of vehicle or road hazards) tasks under both high- and low-load driving conditions when simple or complex advanced traveller information (ATI) was presented visually only, aurally only or by multimodality (visual and auditory) display. For all participants, both the auditory and multimodality displays produced better performance in terms of response times, total number of correct turns and subjective workload ratings than those of using the visual-only display. Participants using the multimodality display also made the fewest errors related to push-button and navigation tasks, and controlled their vehicles properly. The visual display led to less safe driving, apparently because it imposed higher demands on the drivers' attention. An age effect was found in the present study, with younger drivers performing better and reporting less stress than older drivers. Notably, however, use of the multimodality display significantly improved the older drivers' performance in the button-pushing task.     

Aging, motor control, and the performance of computer mouse tasks

Because of the increased presence of computers in work and everyday life and the demographic "graying" of America, there is a need for interface designs that promote accessibility for older people. This study examined age differences in the performance of basic computer mouse control techniques. An additional goal of the study was to examine the influence of age-related changes in psychomotor abilities on mouse control. A total of 60 participants in 3 age groups (20-39 years, 40-59 years, and 60-75 years) performed 4 target acquisition tasks (pointing, clicking, double-clicking, and dragging) using a computer mouse. The data indicated that the older participants had more difficulty performing mouse tasks than the younger participants. Differences in performance attributable to age were found for the more complex tasks (clicking and double-clicking). Furthermore, age-related changes in psychomotor abilities were related to age differences in performance. We discuss applications to computer interface designs. Actual or potential applications of this research include specifications for computer mouse design to accommodate older populations.     

Age, luminance, and print legibility in homes, offices, and public places.

Field studies were conducted in homes, offices, and public places with younger and older adults to determine how legibility performance (in a proofreading and phone book search) changes with age and luminance. Homes and public places generally exhibited much lower than recommended luminance values for reading. Older adults had higher light levels in their homes than did younger adults at reading locations. Older adults performed less quickly than did younger adults on most legibility tasks. Adding light helped younger and older adults equally for most legibility tasks (in homes and public places), though increased luminance differentially improved the performance of older office workers. In response to feedback about low light levels, nearly 60% of building managers in public places indicated in a 6-month follow-up that they had improved lighting or were planning to do so. Actual or potential applications of this work include setting luminance guidelines for adults and identifying barriers to lighting changes.     

The expanding telephone number Part 2: Age variations in immediate memory for multiple-digit numbers

Immediate ordered recall of multiple-digit numbers was investigated in a practical read-and-key or listenand-key task for three age groups whose mean ages were 25.2 years (range 23-27), 44.1 years (range 42-44) and 63.6 years (range 61-68), all recruited from students and faculty staff at the University of Oslo. The two younger groups performed at comparable levels on the immediate memory task, surpassing the performance of the older group for both visual and auditory presentation of the digit-strings. Increasing the presentation time of the numbers affected the young and older age groups similarly by improving the memory performance. Analyses of the serial position curves revealed an enhancement of the well-known modality effect in the older subjects. The overall decline in memory performance observed at the age of 65 should be taken into account in design of communication technology for the general public.     

Divided attention in experienced young and older drivers: lane tracking and visual analysis in a dynamic driving simulator.

A simulated driving task that required the simultaneous execution of two continuous visual tasks was administered to 12 healthy young (mean age 26.1 years) and 12 healthy older (mean age 64.4 years) experienced and currently active drivers. The first task was a compensatory lane-tracking task involving a three-dimensional road display. The second task was a timed, self-paced visual analysis task involving either a vocal or manual binary response to dot patterns projected within the road display. Using adaptive tasks, single-task difficulty was individually adjusted for each subject. To control for individual differences in attention allocation strategy, the dual task was performed according to three different sets of instructions based on the relative importance of each task. Compared with young adults, older adults showed a significantly decreased ability to divide attention. This effect was apparent in lane tracking and in the accuracy of visual analysis. The impairment of divided attention was less pronounced in the vocal condition than in the manual one. This suggests that difficulty in integrating responses may be an important determinant of poor dual-task performance in old age.     

The expanding telephone number Part 2: Age variations in immediate memory for multiple-digit numbers

Immediate ordered recall of multiple-digit numbers was investigated in a practical read-and-key or listenand-key task for three age groups whose mean ages were 25.2 years (range 23-27), 44.1 years (range 42-44) and 63.6 years (range 61-68), all recruited from students and faculty staff at the University of Oslo. The two younger groups performed at comparable levels on the immediate memory task, surpassing the performance of the older group for both visual and auditory presentation of the digit-strings. Increasing the presentation time of the numbers affected the young and older age groups similarly by improving the memory performance. Analyses of the serial position curves revealed an enhancement of the well-known modality effect in the older subjects. The overall decline in memory performance observed at the age of 65 should be taken into account in design of communication technology for the general public.     

Manual dexterity of older Mexican American adults: a cross-sectional pilot experimental investigation

This paper reports results from an experimental pilot study performed to quantify the manual dexterity of older Mexican American adults. The Purdue pegboard test, a two-arm coordination test, and a hand-tool dexterity test were used in this study. To enable cross-sectional comparisons of manual dexterity measures of older Mexican American adults with young Mexican American adults, these tests were administered to 18 older Mexican American adults aged 63–85 (mean age: 71.3 years, SD: 7.0 years), recruited from senior recreation centers in El Paso, and eighteen young adults aged 21–32 (mean age: 25.6 years, SD: 3.8 years) recruited from the student body at the University of Texas at El Paso. For the Purdue pegboard test, the number of pegs placed in 30 s using the preferred hand, the non-preferred hand, and both hands were first individually monitored. Then, scores on an assembly task using the Purdue pegboard were obtained. For the two-arm coordination test, participants were required to trace a star pattern with a stylus using both hands. The time for task completion and the number of errors made during task performance were monitored. For the hand-tool dexterity test, participants were required to use common hand tools and remove nuts and bolts from one side of a wooden upright, and to assemble nuts and bolts in the corresponding holes on the other side of the upright. The time taken for task completion was recorded. Since modified Levene's test showed equality of variances, two sample t-tests, comparing the mean responses of older adults with the mean responses of young adults for each individual test, were conducted. Results indicate that responses for the older adults were statistically significant different (p<0.001) from young adults for all Purdue pegboard tasks. On the average, older adults performed significantly slower (p<0.001) than young adults on the two-arm coordination test, and committed more errors before task completion (p<0.05). Older adults also took longer to complete the hand-tool dexterity task compared to their younger counterparts (p<0.05). In addition to the t-tests, manual dexterity performance measures from older adults were regressed with age to determine the cross-sectional age effects on manual dexterity measures. Results indicate that all Purdue pegboard performance measures were significantly affected by age (p<0.05). The time to complete the two-arm coordination test was significantly linearly related to age (p<0.05). However, the number of errors committed by older adults in the performance of the two-arm coordination test was not significantly linearly related to age. Time to complete the hand-tool dexterity was also significantly linearly related to age (p<0.05). Accommodating age-related changes in manual dexterity is important for job design in industry, especially in industries employing older adults requiring significant assembly and hand-tool use.

Relevance to industry

Given the aging of the industrial workforce, it is important to understand how manual dexterity is affected by age, so that jobs requiring significant manual dexterity for task initiation, task performance and task completion are designed to fit older adult dexterity levels.     

How to Overcome Disorientation in Mobile Phone Menus: A Comparison of Two Different Types of Navigation Aids

The current study was concerned with the basic question of how to overcome users' disorientation when navigating through hierarchical menus in small-screen technical devices, as for example mobile phones. In these devices, menu functions are typically organized in a tree structure. Two different navigation aids were implemented into a computer simulation of a real mobile phone (Siemens S45®). The interface of the first navigation aid (the "category" aid) showed the name of the current category as well as a list of its contents. The interface of the other navigation aid (the "tree" aid) was identical to the first except that it also showed the parents and parent–parents of the current of the category and it indented the subcategories to emphasize the hierarchical structure. For the study, 16 younger (23–28 years) and 16 older adults (46–60 years) had to solve 9 common phone tasks twice consecutively to measure learnability. To gain further insight into user characteristics modulating navigation performance and possibly interacting with the utility of the navigation aids, we assessed users' verbal memory and spatial abilities. Dependent variables were task effectiveness (number of tasks solved) and efficiency (time on task, number of returns in menu hierarchy, and returns to the top). The results reveal a consistent and significant advantage of the tree aid for both age groups, an advantage that was larger for users with lower spatial abilities and older adults. In general, older adults had lower verbal memory and spatial abilities, which were found to account for their lower navigation performance. We assume that the strong advantage of the tree aid is due to the spatial information on the menu structure, which thus conveys survey knowledge. This allows users to form an adequate mental representation of the menu. It is recommended to add a navigation aid providing survey knowledge into the displays of small-screen devices to achieve better overall performance.     

Notebook input devices put to the age test: the usability of trackpoint and touchpad for middle-aged adults

In two experiments, the usability of input devices integrated into computer notebooks was under study. The most common input devices, touchpad (experiment 1) and trackpoint (experiment 2) were examined. So far, the evaluation of mobile input devices has been restricted to younger users. However, due to ongoing demographic change, the main target group of mobile devices will be older users. Therefore, the present study focused on ageing effects. A total of 14 middle-aged (40–65 years) and 20 younger (20–32 years) users were compared regarding speed and accuracy of cursor control in a point-click and a point-drag-drop task. Moreover, the effects of training were addressed by examining the performance increase over time. In total, 640 trials per task and input device were executed. The results show that ageing is a central factor to be considered in input device design. Middle-aged users were significantly slower than younger users when executing the different tasks. Over time, a significant training effect was observed for both devices and both age groups, although the benefit of training was greater for the middle-aged group. Generally, the touchpad performance was higher than the trackpoint performance in both age groups, but the age-related performance decrements were less distinct when using the touchpad.     

Effect of tactile feedback on movement speed and precision during work-related tasks using a computer mouse

Effects of tactile feedback on movement accuracy and speed were studied. Younger and older participants performed three tasks (1, select and drag word; 2, menu navigation; 3, select and drag cell) using commercial software and a mouse with or without tactile feedback. Task time and error number were recorded. Tasks were divided according to presence or absence of tactile feedback, and participants were divided into subgroups (high, average, low) based on Task 1 performance. Overall, older participants took longer (p < .0001) and made more errors (p < .001) than younger participants. There was an effect of feedback by task in younger participants for all six outcomes (p < 0.02). At the task level, with feedback, younger participants reduced performance time (13%) and errors (24%) on Task 1. Low- and average-performance younger participants benefited most from feedback for Task 1. Older low-performance participants also benefited from feedback for Task 1. For Task 3, older participants tended to take more time and make more errors with feedback. Tactile feedback may enhance performance when feedback is event related. Older people may not integrate sensation as well as younger individuals to enhance performance. Potential applications of this research include the development of tactile feedback interfaces to facilitate computer use.     

The effect of age on the hand movement time during machine paced assembly tasks for female workers

The share of older adults in the workforce is increasing in many countries. In the manufacturing industry a high proportion of assembly tasks are machine paced. Previous studies have shown that older adults tend to have longer movement times than younger adults when working at a self-selected pace. However, it is unclear whether older adults can obtain the same hand movement time as a younger group when performing machine paced work at the assembly line. In the current study, 10 older and 10 younger female participants performed simulated light-duty assembly tasks during which the hand movement times were recorded. The results showed that the older participants were capable of working at the set pace and there was no significant difference between age groups in hand movement times (989.9 msec vs. 986.6 msec, p = 0.5647). A likely explanation to the results is that the older participant had to work closer to their physical limits or capacity in order to compensate for the age effect on movement time.     

Notebook input devices put to the age test: the usability of trackpoint and touchpad for middle-aged adults

In two experiments, the usability of input devices integrated into computer notebooks was under study. The most common input devices, touchpad (experiment 1) and trackpoint (experiment 2) were examined. So far, the evaluation of mobile input devices has been restricted to younger users. However, due to ongoing demographic change, the main target group of mobile devices will be older users. Therefore, the present study focused on ageing effects. A total of 14 middle-aged (40-65 years) and 20 younger (20-32 years) users were compared regarding speed and accuracy of cursor control in a point-click and a point-drag-drop task. Moreover, the effects of training were addressed by examining the performance increase over time. In total, 640 trials per task and input device were executed. The results show that ageing is a central factor to be considered in input device design. Middle-aged users were significantly slower than younger users when executing the different tasks. Over time, a significant training effect was observed for both devices and both age groups, although the benefit of training was greater for the middle-aged group. Generally, the touchpad performance was higher than the trackpoint performance in both age groups, but the age-related performance decrements were less distinct when using the touchpad.