Age differences in the performance of information retrieval tasks

In two experiments younger (18-25 years) and older (60-70 years) participants performed an information retrieval task in which they searched for the answers to questions in a hierarchical menu structure. Participants' movement speed, spatial ability, spatial memory, working memory capacity and reasoning speed were measured. Results showed older participants to be slower than younger participants on overall latencies on the information retrieval task. This slowing increases with each consecutive step in the menu structure. Regression analysis showed that movement speed, reasoning speed and spatial ability predicted the overall latencies accurately. Modelling the consecutive steps showed that latencies on the first selection are predicted by movement speed and reasoning speed. Memory and spatial measures are predictors for latencies on steps further into the menu structure only. This finding is consistent with increased slowing of older participants for later selections and suggests that deep menu structures are less suited for older users.     

Age and cognitive ability as predictors of computerized information retrieval

This paper presents an empirical investigation of age and cognitive ability as predictors of computerized information retrieval. Upon the basis of age-related changes in cognitive ability, hypotheses were generated relating to the effects of database structure (linear, hierarchical, or network) and node selection method (explicit or embedded menu). In keeping with previous research in other areas of human-computer interaction, there was a significant main effect of age, with older subjects performing more slowly. However, interactive effects of 'question block' indicated that older subjects were at a particular disadvantage in the early stages of task performance. Age differences in processing speed and/or psychomotor skill appeared to be a particularly important factor. Whilst the effects of cognitive ability were generally weak, spatial memory and logical reasoning scores were negatively correlated with information retrieval response times. Although interactions were not significant, trends in the data for all dependent measures suggested that older subjects may be at a disdvantage when using a network structure.     

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.     

Effects of age,cognitive, and personal factors on PDA menu navigation performance

The present study examined the PDA menu navigation performance of younger and older adults. The research focus was directed to the understanding of the combination and interaction of user characteristics with PDA menu navigation performance. In order to detail individual factors that influence user's performance, users' age, spatial ability, verbal memory, the confidence to use technical devices and computer-expertise were studied and related to performance outcomes. Younger and older adults, experienced with the usage of different technical devices, but PDA novices, had to complete four common tasks in the digital diary of an emulated PDA and users' effectiveness and efficiency were surveyed. Even though the users of both age groups had a comparably high computer experience, participants had considerable difficulties to solve the PDA tasks successfully. Especially older adults were strongly disadvantaged when navigating through the PDA menu. Among the user characteristics which were revealed to be essential for performance, spatial abilities were the best predictor to explain PDA performance. In addition, an adequate mental representation of the PDA data structure was decisive for navigation performance, especially in the older adult group.     

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.     

Effects of age, speech rate, and environmental support in using telephone voice menu systems

Age differences in the use of telephone menu systems were investigated in two experiments. Participants from three age groups (younger: 18-39; middle-aged: 40-59; older: 60+ years) were required to obtain specified information or perform some action using simulated voice menu systems. Measures reflecting task performance, menu navigation, and subjective responses were collected. The focus in Experiment 1 was on examining the effect of speech rate. Data from 196 participants indicated age differences in performance, especially for complex problems. There was no effect of speech rate on any of the performance measures. Experiment 2 examined two types of support devices: a screen phone and a graphical aid. Data from 114 participants indicated that the screen phone provided some benefits in navigational efficiency. In terms of performance, the older participants benefited more from the graphical aid and the younger participants performed better with the screen phone. Actual or potential applications of this research include guidance in the use of support devices that can reduce memory demands and the identification of appropriate speech rates.     

Designing an information search interface for younger and older adults

OBJECTIVE: The present study examined Web-based information retrieval as a function of age for two information organization schemes: hierarchical organization and one organized around tags or keywords. BACKGROUND: Older adults' performance in information retrieval tasks has traditionally been lower compared with younger adults'. The current study examined the degree to which information organization moderated age-related performance differences on an information retrieval task. The theory of fluid and crystallized intelligence may provide insight into different kinds of information architectures that may reduce age-related differences in computer-based information retrieval performance. METHOD: Fifty younger (18-23 years of age) and 50 older (55-76 years of age) participants browsed a Web site for answers to specific questions. Half of the participants browsed the hierarchically organized system (taxonomy), which maintained a one-to-one relationship between menu link and page, whereas the other half browsed the tag-based interface, with a many-to-one relationship between menu and page. This difference was expected to interact with age-related differences in fluid and crystallized intelligence. RESULTS: Age-related differences in information retrieval performance persisted; however, a tag-based retrieval interface reduced age-related differences, as compared with a taxonomical interface. CONCLUSION: Cognitive aging theory can lead to interface interventions that reduce age-related differences in performance with technology. In an information retrieval paradigm, older adults may be able to leverage their increased crystallized intelligence to offset fluid intelligence declines in a computer-based information search task. APPLICATION: More research is necessary, but the results suggest that information retrieval interfaces organized around keywords may reduce age-related differences in performance.     

Modelling of menu design in computerized work

The objective of the research was to propose and validate a theoretically meaningful link between three constructs of hierarchical menu design: menu dimension, task complexity, and user knowledge structure. Twenty-four subjects participated in a nested factorial experiment. The subjects performed a menu retrieval task using a hierarchical menu system constructed for use in the domain of utility boiler control. The dependent variables were time to respond and accuracy. The independent variables were menu dimension, task complexity and user knowledge structure. Four hypotheses were tested. The foundation of the hypotheses was based upon the premise that when task complexity is low, the short-term memory requirements of the menu retrieval task are low. Thus, the user's knowledge structure will not affect performance because it is not required for the chunking of visual information. The objectives of this research were met and are presented in the context of an information processing model for psychomotor tasks.     

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.     

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.     

Effects of Chinese character size,number of characters per line,and number of menu items on visual search task on tablet computer displays for different age groups

The goal of this study was to investigate the effects of Chinese character size, number of characters per line, and number of menu items on visual search task performance on a tablet computer for different age group users. Forty-two participants participated the visual search experiment. Gender, age group (younger, middle-aged, and older), Chinese character size (15, 17, 19, 21, 23, and 25 point), number of characters per line (2–5 characters, 9–14 characters, and 15–18 characters), and number of menu items (5, 7, 9, 11, and 13 items) were the independent variables. The dependent variables included search time and error rate. Gender had a large effect size on search time. Female participants had a faster search time than male participants. Significant differences and large effect sizes were found in search performance for different character sizes, number of characters per line, and number of menu items. Nine to fourteen characters per line achieved the fastest search time and lowest error rate. The fastest search time was for a 19-point character size in the younger group; 21-point character size in the middle-aged group; and 23-point character size in the older group. Besides, the fastest search time was found when showing 9 items in the younger group; 7 items in the middle-aged group; and 5 items in the older group. The optimum visual search performance was achieved with 19-point character size showing 9 items and 9–14 characters per line for the younger group; 21-point character size showing 7 items and 9–14 characters per line for the middle-aged group; and 23-point character size showing 5 items and 9–14 characters per line for the older group. The results provide useful information for tablet computer interface-presentations for different age group users.     

Auditory and visual distractor decrement in older worker manual assembly task learning: Impact of spatial reasoning,field independence,and level of education

This study examined the impact of age on manual assembly task learning in the presence of visual and auditory distracters. Manual assembly task learning (e.g., number of learning trials needed to obtain consistently accurate assembly and near asymptote performance times) was studied in men and women between 18 and 65 years of age. Higher spatial reasoning capabilities were associated with fewer trials to reach the learning criterion, faster manual assembly times, and material prophylaxis for the type of distractors addressed in this study that are likely to be encountered in the workplace. Years of formal education and field independence showed no impact on distractor‐based decrements in task learning. For the oldest group of subjects (>50 years), concomitant presentation of visual and auditory distractors that are commonly encountered in industry were associated with a greater number of learning trials that were needed to achieve asymptotic manual assembly task learning. Spatial reasoning and field independence measures were lower in the older than in the younger age groups (p < 0.05). When spatial reasoning was treated as a covariate, however, nearly all age differences found in learning performance in the face of distractors were removed. The findings suggest that selection of workers based on spatial reasoning ability, rather than age, would yield better manual task learning in the face of visual and auditory distraction. © 2009 Wiley Periodicals, Inc.     

Eye movements of younger and older drivers.

This 2-part study focuses on eye movements to explain driving-related visual performance in younger and older persons. In the first task, participants' eye movements were monitored as they viewed a traffic scene image with a numeric overlay and visually located the numbers in their sequential order. The results showed that older participants had significantly longer search episodes than younger participants, and that the visual search of older adults was characterized by more fixations and shorter saccades, although the average fixation durations remained the same. In the second task, participants viewed pictures of traffic scenes photographed from the driver's perspective. Their task was to assume the role of the driver and regard the image accordingly. Results in the second task showed that older participants allocated a larger percentage of their visual scan time to a small subset of areas in the image, whereas younger participants scanned the images more evenly. Also, older participants revisited the same areas and younger participants did not. The results suggest how aging might affect the efficacy of visual information processing. Potential applications of this research include training older drivers for a more effective visual search, and providing older drivers with redundant information in case some information is missed.     

Affective, anxiety and behavioral effects of an aversive stimulation during a simulated navigation task within a virtual environment: A pilot study

This study investigated the impact of an aversive environmental stimulation on self-reported affective and anxiety states and movement behaviors during a simulated navigation task in a virtual environment (VE). In the experimental task, participants were asked to virtually navigate (within two consecutive sessions), from a starting point to a destination location, across a spatial configuration consisting in three successive corridors (A-C). In the first session, all corridors were non-aversive. In the second session, the corridor B contained an aversive stimulation (i.e., fire, smokescreen, and warning alarm). Fourteen participants were involved in the experiment. Self-reported anxiety and affective states were measured at the end of each session. However, movement indicators (i.e., execution, time, average speed, speed and trajectory variability) were recorded on-line during the experiment. Results showed a significant increased (i) level of self-reported negative affects and state-anxiety between the two sessions, and (ii) speed and trajectory variability between the two sessions, while the participants were in corridor B. In conclusion, these results support the experimental validity of virtual reality for the induction of negative affects and state-anxiety. The relationships between reported negative affects and state-anxiety and behavior are discussed.     

Computer use in older adults: Determinants and the relationship with cognitive change over a 6 year episode

Cognitively challenging activities may support the mental abilities of older adults. The use of computers and the Internet provides divergent cognitive challenges to older persons, and in previous studies, positive effects of computer and Internet use on the quality of life have been demonstrated. The present study addresses two research aims regarding predictors of computer use and the relationship between computer use and changes in cognitive abilities over a 6-year period in both younger (24-49 years) and older adults (older than 50 years). Data were obtained from an ongoing study into cognitive aging: the Maastricht Aging Study, involving 1823 normal aging adults who were followed for 9 years. The results showed age-related differences in predictors of computer use: the only predictor in younger participants was level of education, while in older participants computer use was also predicted by age, sex and feelings of loneliness. Protective effects of computer use were found for measures of selective attention and memory, in both older and younger participants. Effect sizes were small, which suggests that promotion of computer activities in older adults to prevent cognitive decline may not be an efficient strategy.     

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.     

Biomechanical evaluation of heavy tool-handling in two age groups of firemen

The biomechanical load of a rescue-clearing task (lifting a power saw from the floor up to the ceiling level) was evaluated with six older (47 ± 5 years) and seven younger firemen (32 ± 2 years). The mean dynamic compressive force at the L5/SI disc was 5998?N for the older subjects and 6392?N for the younger subjects. The peak torques for the back and knee extensions were about equal for the two groups of the subjects. The younger subjects had a significantly higher movement speed in the knee extension than the older subjects (89.1 ± 25.7 vs. 35.3±11.5°/, p<0.001). The results showed that lifting a power saw produced a high load on the musculoskeletal system, and that the load was not influenced by age.     

Content and representation effects with reasoning tasks in PROLOG form

Abstract

Two experiments were carried out to examine human reasoning performance in the context of the logic programming language PROLOG. Two factors, ‘content’ (familiar versus unfamiliar) and ‘representation’ (diagrammatic versus PROLOG-like list) were investigated. Subjects answered questions about hierarchical relationships in each condition. A significant interaction was obtained in both experiments, subjects making fewer errors in the familiar-diagram and unfamiliar-list conditions than in the familiar-list and unfamiliar-diagram conditions.

It is hypothesized that a lower percentage of correct responses was given in familiar-list and unfamiliar–diagram conditions because the representation of information prevented successful use of an appropriate reasoning strategy. Working memory limitations provide a basis for understanding constraints on reasoning strategies for solving task questions. These strategies may involve either a serial or a spatial solution process. One strategy may require a larger working memory load than another, depending on the representation and content of the task information. Implications for PROLOG programming instruction are discussed.     

Predictors of web navigation performance in a life span sample of adults

The influence of age, subject matter knowledge, working memory, reading abilities, spatial abilities, and processing speed on Web navigation was assessed in a sample of 41 participants between the ages of 19 and 83 years. Each participant navigated a stand-alone tourism Web site to find answers to 12 questions. Performance was measured using time per trial, number of pages per trial, and number of revisited pages per trial. Age did not influence the number of total pages or repeat pages visited, which were predicted by domain knowledge, working memory, and processing speed. Age was associated with slower times per trial, and the effect remained significant after controlling for working memory, processing speed, and spatial abilities. Only with the addition of subject matter knowledge and World Wide Web experience was the age effect eliminated. Actual or potential applications of this research include redesigning Web sites to minimize memory demands and enhance visual segmentation. The data also suggest that age differences in Web navigation can be offset partially by taking advantage of older adults' prior experiences in the domain.     

The effects of screen ratio and order on information retrieval in web pages

Aesthetics can have a pivotal role in the success of Web sites [Interacting with Computers 15 (2003) 429], but need to be considered in conjunction with task performance. Typical Web pages divide the screen into a menu area for navigation and a content area to display information. The Golden Section can be applied to decide on the proportion of these two areas on the screen when designing this type of page. Using a computer-controlled experiment, we examined the role of aesthetics in the use of Web pages. Ninety-eight participants completed an information retrieval task. Analysis of variance showed that the effect of screen ratio (width of menu area to content area) on task performance and subjective outcomes was statistically significant. Application of the Golden Section was found to result in the worst screen ratio. The results are discussed in terms of theories of categorisation and aesthetic behaviour, and design recommendations are given.