Age-Related Differences in Eye Tracking and Usability Performance: Website Usability for Older Adults

Cognitive decline is inherent with age. Despite known cognitive limitations, older adults are generally not taken into account during website design. Understanding age-related differences in website navigation is instructive for website design, especially considering the growing number of older adults who use the Internet. This article presents usability and eye-tracking data from five independent website usability studies that included younger and older participants. Overall results revealed age-dependent differences in eye movement and performance during website navigation on some of the sites. In particular, older participants had lower accuracy in one study and took longer to complete tasks in two studies compared to younger participants, they looked at the central part of the screen more frequently than younger participants in two studies, and they looked at the peripheral left part of the screen less frequently and took longer to first look at the peripheral top part of the screen than younger participants in one study. These data highlight the potential for age-related differences in performance while navigating websites and provide motivation for further exploration. Implications for website design and for usability practitioners are discussed.     

Age differences in search of web pages: the effects of link size, link number, and clutter

Reaction time, eye movements, and errors were measured during visual search of Web pages to determine age-related differences in performance as a function of link size, link number, link location, and clutter. Participants (15 young adults, M = 23 years; 14 older adults, M = 57 years) searched Web pages for target links that varied from trial to trial. During one half of the trials, links were enlarged from 10-point to 12-point font. Target location was distributed among the left, center, and bottom portions of the screen. Clutter was manipulated according to the percentage of used space, including graphics and text, and the number of potentially distracting nontarget links was varied. Increased link size improved performance, whereas increased clutter and links hampered search, especially for older adults. Results also showed that links located in the left region of the page were found most easily. Actual or potential applications of this research include Web site design to increase usability, particularly for older adults.     

Navigating the Online World: Gaze,Fixations, and Performance Differences between Younger and Older Users

ABSTRACT

The world’s populations and workforces are aging and older adults are now the fastest growing group of internet users. Unfortunately, age-related declines may prevent older adults from performing web-based tasks with the same ease as their younger counterparts. Recent studies have suggested that peripheral navigation may exacerbate age-related online performance gaps as older adults fail to adequately search peripheral elements. Such studies have however relied on the use of preexisting websites with no control for layout, complexity, or prior familiarity. This study tested whether age-related differences in online performance and search behavior exist across various navigational layouts. Participants (N = 47) completed four online tasks with purpose-built websites of equivalent difficulty, length, and content type, yet with varying navigational layouts (center; left-periphery; top-periphery; inconsistent). Participants’ performance (i.e., accuracy/efficiency), search behavior (i.e., eye gaze/fixation), and satisfaction were examined. Identifiable differences between age-groups and navigational layouts were found, with top-peripheral navigation proving most detrimental to the online performance and satisfaction of both younger and older adults. The results inform design principles that aim to increase older adults’ online functionality, and provide an extensive platform for further research.     

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.     

Web navigation and the behavioral effects of constantly visible site maps

Knowledge regarding how Web information-seekers behave with respect to the structures and cues they are provided with may shed light on general principles of navigation in electronic spaces, and assist designers in making more informed structural decisions. This study examines user movement through hierarchically structured Web sites and the behavioral effects of a constantly visible, textual contents list for relatively small sites or more extensive local views than are generally used on the Web today. The site overview resulted in users abandoning fewer information-seeking tasks. Users with such context dig deeper into the site structure, make less use of the browser's Back button, and frequently make navigational movements of great hierarchical distances. Navigational correlates of success and reported confidence for users with the overview differ from those without such context. Both with and without a constant overview, the relationship between the source and destination pages may help predict the amount of time spent at the destination. Experimental reports are preceded by a review of click-stream navigation behavior research.     

Age-related biomechanical differences during asymmetric lifting

This study investigated age-related biomechanical differences during asymmetric lifting. Eleven younger and twelve older participants were instructed to lift loads of different weights to an asymmetric destination. The trunk kinematics and low back moments were examined. The results showed that older adults adopted safer lifting strategies compared with younger adults. Specifically, the peak trunk sagittal flexion angle was 32% lower and the peak trunk transverse twisting angle was 22% lower in older adults compared with those in younger adults. It was also found that the average low back moment in the deposit phase was 32% higher in older adults than that in younger adults, most probably due to the age-related increased body weight. Based on these findings and the fact of age-related decreased muscle strengths, physical exercise programs were suggested to be more effective than instructions of safe lifting strategies in LBP risk reduction during asymmetric lifting for older adults. For younger adults, safe lifting strategy instructions might be effective to reduce risks of LBP.     

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.     

根据用户行为网上导航的方法

随着因特网的成长,网络浏览使人们从本地或远程更方便地获取各种信息．网页数量的疯狂增长已经使得用户面对庞大的数据群无所适从,急需导航技术的帮助．一个新的马尔可夫链模型被引入用来跟踪所有团体成员的网页访问活动,并且推荐一些有用站点,引导人们更有效率地浏览网站．还提出一个基于半形式化过程描述的数据搜集算法,来获得有用数据,以推导出最好结果,并在原型系统中分析了代理服务器上的访问日志,对该算法进行描述．     

Age differences in information finding tasks: Performance and visual exploration strategy with different web page layouts

Recent research suggests that older Internet users seem to find it more difficult to locate navigation links than to find information content in web pages. One possibility is that older Internet users’ visual exploration of web pages is more linear in nature, even when this type of processing is not appropriate for the task. In the current study, the eye movements of young and older Internet users were recorded using an ecological version of the web pages or a discursive version designed to induce a linear exploration. The older adults found more targets when performing content-oriented compared to navigation-oriented searches, thus replicating previous results. Moreover, they performed less well than young people only when required to locate navigation links and tended to outperform the younger participants in content-oriented searches. Although the type of search task and type of web page resulted in different visual strategies, little or no support was found for the hypothesis that older participants explore web pages in a more linear way in cases where this strategy was not appropriate. The main conclusion is that differences in visual exploration do not seem to mediate the specific difficulty older adults experience in navigation-oriented searches in web pages.     

Younger and older users׳ recognition of virtual agent facial expressions

As technology advances, robots and virtual agents will be introduced into the home and healthcare settings to assist individuals, both young and old, with everyday living tasks. Understanding how users recognize an agent׳s social cues is therefore imperative, especially in social interactions. Facial expression, in particular, is one of the most common non-verbal cues used to display and communicate emotion in on-screen agents (Cassell et al., 2000). Age is important to consider because age-related differences in emotion recognition of human facial expression have been supported (Ruffman et al., 2008), with older adults showing a deficit for recognition of negative facial expressions. Previous work has shown that younger adults can effectively recognize facial emotions displayed by agents (Bartneck and Reichenbach, 2005, Courgeon et al., 2009, Courgeon et al., 2011, Breazeal, 2003); however, little research has compared in-depth younger and older adults’ ability to label a virtual agent׳s facial emotions, an import consideration because social agents will be required to interact with users of varying ages. If such age-related differences exist for recognition of virtual agent facial expressions, we aim to understand if those age-related differences are influenced by the intensity of the emotion, dynamic formation of emotion (i.e., a neutral expression developing into an expression of emotion through motion), or the type of virtual character differing by human-likeness. Study 1 investigated the relationship between age-related differences, the implication of dynamic formation of emotion, and the role of emotion intensity in emotion recognition of the facial expressions of a virtual agent (iCat). Study 2 examined age-related differences in recognition expressed by three types of virtual characters differing by human-likeness (non-humanoid iCat, synthetic human, and human). Study 2 also investigated the role of configural and featural processing as a possible explanation for age-related differences in emotion recognition. First, our findings show age-related differences in the recognition of emotions expressed by a virtual agent, with older adults showing lower recognition for the emotions of anger, disgust, fear, happiness, sadness, and neutral. These age-related difference might be explained by older adults having difficulty discriminating similarity in configural arrangement of facial features for certain emotions; for example, older adults often mislabeled the similar emotions of fear as surprise. Second, our results did not provide evidence for the dynamic formation improving emotion recognition; but, in general, the intensity of the emotion improved recognition. Lastly, we learned that emotion recognition, for older and younger adults, differed by character type, from best to worst: human, synthetic human, and then iCat. Our findings provide guidance for design, as well as the development of a framework of age-related differences in emotion recognition.     

Visual search for traffic signs: the effects of clutter, luminance, and aging

Latency and eye movement measures were used to examine the effects of aging, clutter, and luminance on visual search for traffic signs embedded in digitized images of driving scenes. Initially 14 older and 14 younger observers classified daytime and nighttime traffic scenes as containing low or high amounts of clutter. Next, an independent sample of 14 younger and 14 older participants searched for traffic signs contained within these scenes. Errors were more common among the elderly. Search efficiency declined with increased clutter and with aging. However, relative to the young, older adults did not suffer disproportionately as a result of increased clutter. The methods developed might be profitably employed to assess sign conspicuity and sign acquisition during driving.     

Vertical versus dynamic menus on the world wide web: Eye tracking study measuring the influence of menu design and task complexity on user performance and subjective preference

Web sites need fast and effective navigation systems. An eye tracking laboratory study with n = 120 participants was conducted to compare the influence of different navigation designs (vertical versus dynamic menus) and task complexity (simple versus complex navigation tasks) on user performance, navigation strategy, and subjective preference. With vertical menus, users needed less eye fixations, were faster and more successful. We conclude that, firstly, vertical menus fit better to perception and cognition than dynamic menus, where the navigation items are hidden and must be accessed by an additional mouse click. Secondly, navigation systems should be extended with different kinds of navigation items adapted to the complexity of the users’ navigation tasks, because users tend to switch their navigation strategy when confronted with complex tasks.     

DENIM: An Informal Web Site Design Tool Inspired by Observations of Practice

Through a study of Web site design practice, we observed that designers employ multiple representations of Web sites as they progress through the design process and that these representations allow them to focus on different aspects of the design. In particular, we observed that Web site designers focus their design efforts at 3 different levels of granularity-site map, storyboard, and individual page-and that designers sketch at all levels during the early stages of design. Sketching on paper is especially important during the early phases of a project, when designers wish to explore many design possibilities quickly without focusing on low-level details. Existing Web design tools do not support such exploration tasks well, nor do they adequately integrate multiple site representations. Informed by these observations we developed DENIM: an informal Web site design tool that supports early phase information and navigation design of Web sites. It supports sketching input, allows design at different levels of granularity, and unifies the levels through zooming. Designers are able to interact with their sketched designs as if in a Web browser, thus allowing rapid creation and exploration of interactive prototypes. Based on an evaluation with professional designers as well as usage feedback from users who have downloaded DENIM from the Internet, we have made numerous improvements to the system and have received many positive reactions from designers who would like to use a system like DENIM in their work.     

一个自适应Web站点构架的设计

现今Web站点是越来越复杂而且不智能化。用户在访问Web站点时经常会碰到很多问题,主要原因是Web站点对用户的需求缺乏适应性。文中研究了自适应Web站点,提出一个理论框架,并针对此框架给出一个构建自适应Web站点的系统架构,介绍了使用文本挖掘方法和Web用法挖掘方法,改善Web站点的结构和组织形式以使站点达到更好的效果。主要通过挖掘Web服务器日志数据使站点更容易访问。     

The effects of 3D interface metaphor on older adults’ mobile navigation performance and subjective evaluation

Navigating vast information spaces through mobile interfaces has become a common activity in older adults' everyday lives. Studies suggested that interface metaphors could be used to facilitate users' metal model development and information processing when using mobile technologies. However, we know little about how metaphors affect older adults' mobile navigation behavior, and which user characteristics matter during this perceptual and cognitive process. To investigate this, a card interface with a 3D metaphor and a list interface without 3D metaphors were compared among twenty-two participants when performing four navigation tasks. User characteristics including demographic factors, technology experience, and user capabilities were examined. The participants' navigation performance and subjective evaluations were measured as the dependent variables. From the results, we recommend the list interface without 3D metaphors as a beneficial choice for older adults. It performed better in navigation performance, although the differences are not statistically significant. Moreover, navigation performance using the card interface with a 3D metaphor was significantly associated with participants' perceptual speed, thus this interface may be more sensitive to capability declines. Valuable insights into the older adults’ mobile navigation performance and preferences are discussed and important implications for the design of mobile navigation user interfaces are proposed based on the results.Relevance to industryThe experimental results propose a more beneficial way to present contents on a mobile user interface for older adults and provide valuable insights for the designers and industry to help them understand the older adults’ usage and perceptions towards the application of 3D metaphors when navigating with mobile interfaces.     

Impacts of navigation structure,task complexity,and users’ domain knowledge on Web site usability—an empirical study

It is essential for designers of Web sites to understand what navigation structure results in better usability for knowledge acquisition tasks of varying complexity and the Web site users with different level of domain knowledge. Literature shows that multiple factors may exert influence on Web site usability. Navigation structure, task complexity, and user domain knowledge level are among of those factors. Hypotheses are developed about the usability of alternative navigation structures, with different task complexity and user domain knowledge level. Experiments are designed and conducted to test these hypotheses in terms of user performance (accuracy, speed) in accomplishing sets of simple and comparatively complex knowledge acquisition tasks. User perceptions of usability are also measured. Two rounds of experimentation are performed, one with participants who have been trained in the domain of production and operations management, the other with participants who have not been trained in this domain. The results show that a usage-oriented hierarchy or a combined hierarchy are navigation structures associated with statistically significantly higher performance usability than a subject-oriented hierarchy, for both simple and relatively complex knowledge acquisition task sets. A statistically significant effect of domain knowledge on the perception aspect of usability is identified. The study contributes to enhancing the comprehension of researchers, practitioners, and educators about design and usability of Web site navigation structures.     

Helping older pedestrians navigate in the city: comparisons of visual,auditory and haptic guidance instructions in a virtual environment

Preserving older pedestrians’ navigation skills in urban environments is a challenge for maintaining their quality of life. However, existing aids do not take into account older people’s perceptual and cognitive declines nor their user experience, and they call upon sensory modalities that are already used during walking. The present study was aimed at comparing different guidance instructions using visual, auditory, and haptic feedback in order to identify the most efficient and best accepted one(s). Sixteen middle-age (non-retired) adults, 21 younger-old (young-retired) adults, and 21 older-old (old-retired) adults performed a navigation task in a virtual environment. The task was performed with visual feedback (directional arrows superimposed on the visual scenes), auditory feedback (sounds in the left/right ear), haptic feedback (vibrotactile information delivered by a wristband), combinations of different types of sensory feedback, or a paper map. The results showed that older people benefited from the sensory guidance instructions, as compared to the paper map. Visual and auditory feedbacks were associated with better performance and user experience than haptic feedback or the paper map, and the benefits were the greatest among the older-old participants, even though the paper-map familiarity was appreciated. Several recommendations for designing pedestrian navigation aids are proposed.     

Towards adaptive Web sites: conceptual framework and case study

The creation of a complex Web site is a thorny problem in user interface design. In this paper we explore the notion of adaptive Web sites: sites that semi-automatically improve their organization and presentation by learning from visitor access patterns. It is easy to imagine and implement Web sites that offer shortcuts to popular pages. Are more sophisticated adaptive Web sites feasible? What degree of automation can we achieve?To address the questions above, we describe the design space of adaptive Web sites and consider a case study: the problem of synthesizing new index pages that facilitate navigation of a Web site. We present the PageGather algorithm, which automatically identifies candidate link sets to include in index pages based on user access logs. We demonstrate experimentally that PageGather outperforms the Apriori data mining algorithm on this task. In addition, we compare PageGather's link sets to pre-existing, human-authored index pages.     

On the efficiency of keyboard navigation in Web sites

An efficient keyboard access to Web sites is highly important for many groups of disabled users. However, the current design of most Web sites makes the efficient keyboard navigation nearly impossible. This paper investigates the performance of the keyboard and mouse navigation in Web pages. The comparison is based on the theoretical arguments and on two small studies. The results show that the current amount of keyboard support in common Web sites is far from being sufficient. Typical problems concerning keyboard support in Web sites are discussed, along with possible solutions and the related constraints.

Using Site Semantics to Analyze, Visualize, and Support Navigation

To satisfy potential customers of a Web site and to lead them to the goods offered by the site, one should support them in the course of navigation they have embarked on. This paper presents the tool STRATDYN, developed as an add-on module to the Web Usage Miner WUM. WUM not only discovers frequent sequences, but it also allows the inspection of the different paths through the site. STRATDYN extends these capabilities: It tests differences between navigation patterns, described by a number of measures of success and strategy, for statistical significance. This can help to single out the relevant differences between users' behaviors, and it can determine whether a change in the site's design has had the desired effect. STRATDYN also exploits the site's semantics in the classification of navigation behavior and in the visualization of results, displaying navigation patterns as alternative paths through a strategy space. This helps to understand the Web logs, and to communicate analysis results to non-experts. Two case studies investigate search in an online catalog and interaction with an electronic shopping agent in an online store. They show how the results of analysis can lead to proposals for improving a Web site. These highlight the importance of investigating measures not only of eventual success, but also of process, to help users navigate towards the site's offers.