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

Development of a quantitative measurement on visual clutter in see through display

Objective

With the wide use of transmission displays to improve operation performance, the display information highlights clutter because of the contradiction between the massive amount of information and limited display area. Our study aimed to develop a quantitative measurement for declutter design and appraisal.

Methods

Using the ergonomics research system of characters and symbols in a see-through cockpit display, we set the simulated flight task interface at four pixel scale levels by enlarging all the display elements in a certain ratio. Flight task videos of 12 clutter degrees were recorded using each flight interface matched with three flight scene complexity levels. A total of 60 pilots completed the visual search tasks in the flight task video while the eye tracker was used to record the view path in real time. Visual search performance was analyzed to study the effect of various clutter factors and levels on pilots' performance in visual search tasks, and acquire quantitative clutter measure parameters.

Results

GLM univariate test revealed that there were significant differences among the fixation time in areas of interest (AOI), total Fixation point number, total fixation time at four pixel scale levels, and three flight scene complexity levels (P < 0.05). Visual search performance declined after the cutoff point, while the clutter degree increased. According to the visual search performance data, the recommend feature congestion upper pixel number limit in a 600*800 display was 18,576, and the pixel ratio was 3.87%.

Conclusion

A quantitative measurement for declutter design and appraisal of cockpit displays was developed, which can be used to support see-through display design.

Searching in clutter: Visual behavior and performance of expert action video game players

Searching for targets among distractors in visual scenes can be more difficult due to the presence of clutter. However, studies in various domains have shown differentiated effects according to the expertise of the searcher. The present study extended these findings to the domain of action video games expertise. 58 participants, split in 2 groups (action video game players and non-action video game players) searched for targets in visual scenes under two clutter conditions (uncluttered and high clutter). Reaction times and accuracy served as measures of performance, and the visual behavior was assessed using the number and duration of eye fixations. Our findings suggest that visual clutter has a negative influence on performance and alters the visual behavior during visual search in action video game scenes. Our results also suggest that expert action video game players might use different visual strategies to cope with clutter, leading however to no performance benefits.

Refinement and preliminary evaluation of two tablet-based tests of real-world visual function

Purpose

To describe, refine, evaluate, and provide normative control data for two freely available tablet‐based tests of real‐world visual function, using a cohort of young, normally‐sighted adults.

Methods

Fifty young (18–40 years), normally‐sighted adults completed tablet‐based assessments of (1) face discrimination and (2) visual search. Each test was performed twice, to assess test‐retest repeatability. Post‐hoc analyses were performed to determine the number of trials required to obtain stable estimates of performance. Distributions were fitted to the normative data to determine the 99% population‐boundary for normally sighted observers. Participants were also asked to rate their comprehension of each test.

Results

Both tests provided stable estimates in around 20 trials (~1–4 min), with only a further reduction of 14%–17% in the 95% Coefficient of Repeatability (CoR₉₅) when an additional 40 trials were included. When using only ~20 trials: median durations for the first run of each test were 191 s (Faces) and 51 s (Search); test‐retest CoR₉₅ were 0.27 d (Faces) and 0.84 s (Search); and normative 99% population‐limits were 3.50 d (Faces) and 3.1 s (Search). No participants exhibited any difficulties completing either test (100% completion rate), and ratings of task‐understanding were high (Faces: 9.6 out of 10; Search: 9.7 out of 10).

Conclusions

This preliminary assessment indicated that both tablet‐based tests are able to provide simple, quick, and easy‐to‐administer measures of real‐world visual function in normally‐sighted young adults. Further work is required to assess their accuracy and utility in older people and individuals with visual impairment. Potential applications are discussed, including their use in clinic waiting rooms, and as an objective complement to Patient Reported Outcome Measures (PROMs).

Display clutter and its effects on visual attention distribution and financial risk judgment

Display clutter is a widely studied phenomenon in ergonomics, where information density and other properties of task-relevant visualizations are related to effective user performance and visual attention. This paper examines the impact of clutter in the context of financial stock visualizations. Depending on their expertise, traders can use a variety of different cues to judge the current and future value of a stock and to assess its riskiness. In our study, two groups of participants (novices and experts) judge the riskiness of 28 pairs of stocks under two clutter conditions (low and high). Consistency of judgments and group concordance serve as measures for judgment performance, while mean fixation duration, fixation frequency, and transition matrix density are employed to capture visual attention. Our results reveal significant effects of display clutter and expertise on both the performance measures as well as the visual attention measures.

Hybrid foraging search in younger and older age

In hybrid foraging tasks, observers search visual displays, so called patches, for multiple instances of any of several types of targets with the goal of collecting targets as quickly as possible. Here, targets were photorealistic objects. Younger and older adults collected targets by mouse clicks. They could move to the next patch whenever they decided to do so. The number of targets held in memory varied between 8 and 64 objects, and the number of items (targets and distractors) in the patches varied between 60 and 105 objects. Older adults foraged somewhat less efficiently than younger adults due to a more exploitative search strategy. When target items became depleted in a patch and search slowed down, younger adults acted according to the optimal foraging theory and moved on to the next patch when the instantaneous rate of collection was close to their average rate of collection. Older adults, by contrast, were more likely to stay longer and spend time searching for the last few targets. Within a patch, both younger and older adults tended to collect the same type of target in "runs." This behavior is more efficient than continual switching between target types. Furthermore, after correction for general age-related slowing, RT × set size functions revealed largely preserved attention and memory functions in older age. Hybrid foraging tasks share features with important real-world search tasks. Differences between younger and older observers on this task may therefore help to explain age differences in many complex search tasks of daily life. (PsycINFO Database Record (c) 2019 APA, all rights reserved).

Too much or too little? Investigating the usability of high and low data displays of the same electronic medical record

The high data density on electronic medical record screens is touted as a major usability issue. However, it may not be a problem if the data is relevant and well-organized. Our objective was to test this assumption using a comprehensive set of measures that assess the three pillars of usability: efficiency (both physical and cognitive), effectiveness, and satisfaction. Physicians were asked to go through a series of tasks using two versions of the same electronic medical record: one where all the display items were separated into tabs (the original display), and one where important display items were grouped logically in one tab (the redesigned display). Results supported the hypothesis that combining relevant data in organized fashion into a smaller location would improve usability. The findings highlight the role of good display organization to mitigate the effects of high data density, as well as the importance of assessing cognitive load as part of usability studies.

Information sharing across generations and environments (InfoSAGE): study design and methodology protocol

Background

Longevity creates increasing care needs for healthcare providers and family caregivers. Increasingly, the burden of care falls to one primary caregiver, increasing stress and reducing health outcomes. Additionally, little has been published on adults’, over the age of 75, preferences in the development of health information sharing with family members using online platforms. This study aims to assess a novel, Internet based, family-centric communication and collaboration platform created to address the information needs of elders and their informal caregivers in a community setting.

Methods

This study is an internet-based, open prospective cohort study, enrolling dyad pairs of one adult over the age of 75 with one informal caregiver. Dyads will be offered to use the InfoSAGE online platform without prospective assignment. Participants will consent using an online process that enables participation from any location and shares important study and privacy details. The platform will enable the capture of search queries and tracking of functions such as tasks and discussions. Surveys every six months assess health status, health and social needs, and caregiver burden using validated instruments over a two-year period. We will use a mixed methods approach, utilizing qualitative survey data along with website usage analytic data.

Discussion

Analysis of the longitudinal usage and survey data will help to examine the patterns of family communication and health information seeking as the central older adult ages. We will use the study data to inform design recommendations relevant to a complex mixture of users, with special consideration to the needs of older adult users and potential physical limitations.

Habitual versus goal-driven attention

Recent research has expanded the list of factors that control spatial attention. Beside current goals and perceptual salience, statistical learning, reward, motivation and emotion also affect attention. But do these various factors influence spatial attention in the same manner, as suggested by the integrated framework of attention, or do they target different aspects of spatial attention? Here I present evidence that the control of attention may be implemented in two ways. Whereas current goals typically modulate where in space attention is prioritized, search habits affect how one moves attention in space. Using the location probability learning paradigm, I show that a search habit forms when people frequently find a visual search target in one region of space. Attentional cuing by probability learning differs from that by current goals. Probability cuing is implicit and persists long after the probability cue is no longer valid. Whereas explicit goal-driven attention codes space in an environment-centered reference frame, probability cuing is viewer-centered and is insensitive to secondary working memory load and aging. I propose a multi-level framework that separates the source of attentional control from its implementation. Similar to the integrated framework, the multi-level framework considers current goals, perceptual salience, and selection history as major sources of attentional control. However, these factors are implemented in two ways, controlling where spatial attention is allocated and how one shifts attention in space.

Technology and Aging

Technological advancements have become widespread, and their implementation into products of everyday use is accelerating. Technology has the potential to improve the lives of older adults by increasing their safety, security, and independence in daily life. However, too often older adults' capabilities and limitations are not considered in the design of current and future technologies. In 1990, the National Research Council identified the importance of human factors in the design of technology for an aging population. The goal of this chapter is to review research on aging and technology since that report to determine the contributions of human factors research to issues of aging and technology design. In this chapter we address the extent to which older adults use new technologies, factors to consider in the adoption of technology (e.g., attitudes), the influence of technology design on older adults' performance (e.g., design of input devices), and ways to optimize training for older adults in using new technologies (e.g., age-specific instructional designs). We then review emerging areas of research that may direct the focus of human factors research in the next decade. These areas of research include ubiquitous computing (e.g., home monitoring systems), health care technologies (e.g., telehealth), robotics (e.g., Nursebot), and automated systems (e.g., cruise control). Finally, we consider opportunities and challenges to human factors research as the field continues to address the questions of optimizing technology for older adult users.

Clutter in electronic medical records: examining its performance and attentional costs using eye tracking

OBJECTIVE

The objective was to use eye tracking to trace the underlying changes in attention allocation associated with the performance effects of clutter, stress, and task difficulty in visual search and noticing tasks.

BACKGROUND

Clutter can degrade performance in complex domains, yet more needs to be known about the associated changes in attention allocation, particularly in the presence of stress and for different tasks. Frequently used and relatively simple eye tracking metrics do not effectively capture the various effects of clutter, which is critical for comprehensively analyzing clutter and developing targeted, real-time countermeasures.

METHOD

Electronic medical records (EMRs) were chosen as the application domain for this research. Clutter, stress, and task difficulty were manipulated, and physicians' performance on search and noticing tasks was recorded. Several eye tracking metrics were used to trace attention allocation throughout those tasks, and subjective data were gathered via a debriefing questionnaire.

RESULTS

Clutter degraded performance in terms of response time and noticing accuracy. These decrements were largely accentuated by high stress and task difficulty. Eye tracking revealed the underlying attentional mechanisms, and several display-independent metrics were shown to be significant indicators of the effects of clutter.

CONCLUSION

Eye tracking provides a promising means to understand in detail (offline) and prevent (in real time) major performance breakdowns due to clutter.

APPLICATION

Display designers need to be aware of the risks of clutter in EMRs and other complex displays and can use the identified eye tracking metrics to evaluate and/or adjust their display.

Display clutter: a review of definitions and measurement techniques

OBJECTIVE

We aimed to synthesize the literature on display clutter by reviewing definitions and measurement techniques and to develop a comprehensive, ergonomics-oriented perspective on clutter. We provide guidance for the selection of measurement approaches that can capture the various aspects and effects of clutter on visual search in particular.

BACKGROUND

There is agreement that clutter may represent a significant problem to operators. The challenge is to determine the ideal middle ground between excessive data and insufficient information. However, definitions of clutter vary widely, which explains the range of measurement approaches, including image-processing algorithms, performance evaluation, subjective evaluation, and eye tracking. It is important to understand the affordances of each technique and provide guidance for their use.

METHOD

We provide a systematic review of clutter definitions and develop a performance-oriented perspective for ergonomics research. Next, we present a critical overview of clutter measurement approaches. The benefits and limitations of each technique are detailed, and recommendations for best practice are provided.

RESULTS

From an ergonomics perspective, clutter matters to the extent that it affects performance, particularly, visual search. A combination of measurement techniques can be employed in order to assess the performance costs stemming from the multiple aspects of clutter.

CONCLUSION

Display clutter is a multifaceted construct that is a problem when it results in performance and attentional costs. The assessment of these costs is critical and requires the use of appropriate and complementary techniques.

APPLICATION

It is important that the performance costs of clutter are detected reliably to be able to better support attention management.

ReadingMate: the effect of the content stabilizing technique, font size, and interline spacing on the letter-counting task performance of treadmill runners

OBJECTIVE

The aim of this study was to investigate the effects of font size, interline spacing, and a technology called ReadingMate on the letter-counting task performance of users running on a treadmill.

BACKGROUND

Few researchers have investigated how runners read text while running on a treadmill. Our previous studies showed that ReadingMate had positive effects on the reading-while-running experience; however, the effect of other text conditions (i.e., font size and interline spacing) and the interplay between ReadingMate and such text conditions on the letter-counting task performance are not clearly understood.

METHOD

Fifteen participants were recruited for the experiment. There were three main factors: display types (normal and ReadingMate), font sizes (8, 12, 16, and 20 point), and interline spacing (1.0x, 1.5x, 2.0x, and 2.5x). The researchers employed a letter-counting task. The performance was measured regarding task performance time, success rate of counting the target letter f and number of give-ups.

RESULTS

Overall, the letter-counting task performance while running on a treadmill improved as font size and interline spacing increased, as expected. ReadingMate was more effective than normal display particularly when text was displayed in a small font size and with dense interline spacing.

CONCLUSION

When text must be displayed in a small font size and with dense interline spacing, ReadingMate can be used to improve the users' task performance.

APPLICATION

Practical applications of ReadingMate include improving the text-reading experience in shaky environments, such as in aviation, construction, and transportation.

Dealing with illumination in visual scenes: effects of ageing and Alzheimer's disease

Various visual functions decline in ageing and even more so in patients with Alzheimer's disease (AD). Here we investigated whether the complex visual processes involved in ignoring illumination-related variability (specifically, cast shadows) in visual scenes may also be compromised. Participants searched for a discrepant target among items which appeared as posts with shadows cast by light-from-above when upright, but as angled objects when inverted. As in earlier reports, young participants gave slower responses with upright than inverted displays when the shadow-like part was dark but not white (control condition). This is consistent with visual processing mechanisms making shadows difficult to perceive, presumably to assist object recognition under varied illumination. Contrary to predictions, this interaction of "shadow" colour with item orientation was maintained in healthy older and AD groups. Thus, the processing mechanisms which assist complex light-independent object identification appear to be robust to the effects of both ageing and AD. Importantly, this means that the complexity of a function does not necessarily determine its vulnerability to age- or AD-related decline.We also report slower responses to dark than light "shadows" of either orientation in both ageing and AD, in keeping with increasing light scatter in the ageing eye. Rather curiously, AD patients showed further slowed responses to "shadows" of either colour at the bottom than the top of items as if they applied shadow-specific rules to non-shadow conditions. This suggests that in AD, shadow-processing mechanisms, while preserved, might be applied in a less selective way.

Aging and performance on an everyday-based visual search task

Research on aging and visual search often requires older people to search computer screens for target letters or numbers. The aim of this experiment was to investigate age-related differences using an everyday-based visual search task in a large participant sample (n=261) aged 20-88 years. Our results show that: (1) old-old adults have more difficulty with triple conjunction searches with one highly distinctive feature compared to young-old and younger adults; (2) age-related declines in conjunction searches emerge in middle age then progress throughout older age; (3) age-related declines are evident in feature searches on target absent trials, as older people seem to exhaustively and serially search the whole display to determine a target's absence. Together, these findings suggest that declines emerge in middle age then progress throughout older age in feature integration, guided search, perceptual grouping and/or spreading suppression processes. Discussed are implications for enhancing everyday functioning throughout adulthood.

Trust in the internet as a health resource among older adults: analysis of data from a nationally representative survey

Background

Distrust in the Internet as a source of health information remains common among older adults. The influence of this distrust on Internet use for health-related purposes, however, is unclear.

Objective

The objective of our study was to explore how older adults’ trust in the Internet influences their online health-related activities, and to identify potential targets for improving health-related Internet resources for older adults.

Methods

Data were obtained from a nationally representative, random digit-dial telephone survey of 1450 adults 50 years of age and older in the United States. A model was developed to conceptualize the hypothesized relationships among individual characteristics, distrust, and avoidance of the Internet as a health resource. Multivariate logistic regression analyses were conducted to examine the association between trust in online health information and use of the Internet for health-related purposes. Additional multivariate logistic regression analyses were conducted to identify the key characteristics associated with trust in online health information, adding sequentially the variables hypothesized to account for distrust among older adults: sociodemographic and health characteristics, inexperience and technical difficulties with the Internet, negative feelings toward the Internet, and lack of awareness about the sources providing the health information found online.

Results

The mean (SD) age of the study population was 63.7 (10.6) years. Of the 823 (56.8%) Internet users, 628 (76.3%) reported using the Internet as a health resource. Trust in the Internet as a source of health information was associated with using the Internet for a number of health activities, including searching for information about a specific health condition (adjusted OR 4.43, P < .001), purchasing prescription drugs (adjusted OR 2.61, P = .03), and talking with a health care provider about information found online (adjusted OR 2.54, P = .002). Older adults (age ≥65 years) were less likely to trust the Internet as a source of health information (OR 0.63, P = .04), even after adjusting for other sociodemographic characteristics and health and function. This age effect was only slightly attenuated (adjusted OR 0.69, P = .13) after adjusting for inexperience and technical difficulties with the Internet, but it disappeared entirely (adjusted OR 0.96, P = .91) after adjusting for other hypothesized contributors to distrust (including finding the Internet confusing because it provides “too much information,” and lacking awareness about the source providing health information found online).

Conclusions

Website design features that clearly identify the source and credibility of information and minimize confusion may build trust among older adults and offer an opportunity to increase the utility of the Internet as a health resource for this population.