Health monitoring technology in everyday situations is expected to improve quality of life and support aging populations. Mental fatigue among health indicators of individuals has become important due to its association with cognitive performance and health outcomes, especially in older adults. Previous models using eye-tracking measures allow inference of fatigue during cognitive tasks, such as driving, but they require us to engage in specific cognitive tasks. In addition, previous models were mainly tested by user groups that did not include older adults, although age-related changes in eye-tracking measures have been reported especially in older adults. Here, we propose a model to detect mental fatigue of younger and older adults in natural viewing situations. Our model includes two unique aspects: (i) novel feature sets to better capture fatigue in natural-viewing situations and (ii) an automated feature selection method to select a feature subset enabling the model to be robust to the target's age. To test our model, we collected eye-tracking data from younger and older adults as they watched video clips before and after performing cognitive tasks. Our model improved detection accuracy by up to 13.9% compared with a model based on the previous studies, achieving 91.0% accuracy (chance 50%).

Crowdsourcing for social goals (e.g., supporting public libraries or people with disabilities) is a promising area. However, little is known about how to develop active worker communities for such goals. First, we need reliable metrics for the workers' motivation. Second, the characteristics of senior crowd workers have rarely been studied, even though they often play a primary role in social-purpose work. This work introduces a four-quadrant worker motivation model for social-purpose crowdsourcing and describes a system based on that model. Then we investigate the outcomes from the system's operations for six months, which involved both young and senior workers, seeking better ways to build an active community of crowd workers. We analyzed the workers' activities based on the system logs, conducted a survey, assessed the correlations between the subjective values and actual behaviors, and then discuss the implications.

Online Web applications have become widespread and have made our daily life more convenient. However, older adults often find such applications inaccessible because of age-related changes to their physical and cognitive abilities. Two of the reasons that older adults may shy away from the Web are fears of the unknown and of the consequences of incorrect actions. We are extending a voice-based augmentation technique originally developed for blind users. We want to reduce the cognitive load on older adults by providing contextual support. An experiment was conducted to evaluate how voice augmentation can support elderly users in using Web applications. Ten older adults participated in our study and their subjective evaluations showed how the system gave them confidence in completing Web forms. We believe that voice augmentation may help address the users' concerns arising from their low confidence levels.

Auditory user interfaces have great Web-access potential for billions of people with visual impairments, with limited literacy, who are driving, or who are otherwise unable to use a visual interface. However a sequential speech-based representation can only convey a limited amount of information. In addition, typical auditory user interfaces lose the visual cues such as text styles and page structures, and lack effective feedback about the current focus. To address these limitations, we created Sasayaki (from whisper in Japanese), which augments the primary voice output with a secondary whisper of contextually relevant information, automatically or in response to user requests. It also offers new ways to jump to semantically meaningful locations. A prototype was implemented as a plug-in for an auditory Web browser. Our experimental results show that the Sasayaki can reduce the task completion times for finding elements in webpages and increase satisfaction and confidence.

We conducted a series of experiments to assess the feasibility of synthesized narrations to describe online videos. To reduce the cultural bias, we included adult blind or low-vision participants from Japan and the U.S. in the main study. Our research also includes a follow-up study we conducted in Japan to assess the effectiveness of synthesized video descriptions in realistic situations. The results showed that synthesized video descriptions were generally accepted in both countries. We also found that appropriate technology support allowed a novice describer to make effective video descriptions. Based on these results, we discuss the implications for developing a technology platform for describing online videos.

We describe an initial attempt to develop a common platform for adding an audio description (AD) to an online video so that blind and visually impaired people can enjoy such material. A speech synthesis technology allows content providers to offer the AD at minimal cost. We exploit external metadata so that the AD can be independent of the video format. The external approach also allows external supporters to add ADs to any online videos. Our technology includes an authoring tool for writing AD scripts, a Web browser add-on for synthesizing ADs synchronized with original videos, and a text-based format to exchange AD scripts.

Collaborative accessibility improvement has great potential to make the Web more adaptive in a timely manner by inviting users into the improvement process. The Social Accessibility Project is an experimental service for a new needs-driven improvement model based on collaborative metadata authoring technologies. In 10 months, about 18,000 pieces of metadata were created for 2,930 webpages through collaboration. We encountered many challenges as we sought to create a new mainstream approach. The productivity of the volunteer activities exceeded our expectation, but we found large and important problems in the screen reader users' lack of awareness of their own accessibility problems. In this paper, we first introduce examples, analyze some statistics from the pilot service and then discuss our findings and challenges. Three future directions including site-wide authoring are considered.

Web content is under the control of site owners, and therefore the site owners have the responsibility to make their content accessible. This is a basic assumption of Web accessibility. Users who want access to inaccessible content must ask the site owners for help. However, the process is slow and too often the need is mooted before the content becomes accessible. Social Accessibility is an approach to drastically reduce the burden on site owners and to shorten the time to provide accessible Web content by allowing volunteers worldwide to - renovate' any webpage on the Internet. Users encountering Web access problems anywhere at any time will be able to immediately report the problems to a social computing service. Volunteers can be quickly notified, and they can easily respond by creating and publishing the requested accessibility metadata--also helping any other users who encounter the same problems. Site owners can learn about the methods for future accessibility renovations based on the volunteers' external metadata. There are two key technologies to enable this process, the external metadata that allows volunteers to annotate existing Web content, and the social computing service that supports the collaborative renovations. In this paper, we will first review previous approaches, and then propose the Social Accessibility approach. The scenario, implementation, and results of a pilot service are introduced, followed by discussion of future directions.

We propose the "ninja cursor" to improve the performance of target acquisition, particularly on large screens. This technique uses multiple distributed cursors to reduce the average distance to targets. Each cursor moves synchronously following mouse movement. We present the design and implementation of the proposed technique, including a method to resolve the ambiguity that results when multiple cursors indicate different targets simultaneously. We also conducted an experiment to assess the performance of the ninja cursor. The results indicate that it can generally reduce movement time. However, the performance is greatly affected by the number of cursors and target density. Based on these results, we discuss how our technique can be put into practical use. In addition to presenting a novel method to improve pointing performance, our study is the first to explore a variable number of cursors for performing pointing tasks.

We present the boomerang technique, which makes it possible to suspend and resume drag-and-drop operations. A throwing gesture while dragging an object suspends the operation, anytime and anywhere. A drag-and-drop interaction, enhanced with our technique, allows users to switch windows, invoke commands, and even drag other objects during a drag-and-drop operation without using the keyboard or menus. We explain how a throwing gesture can suspend drag-and-drop operations, and describe other features of our technique, including grouping, copying, and deleting dragged objects. We conclude by presenting prototype implementations and initial feedback on the proposed technique.

Cascading menus are commonly seen in most GUI systems. However, people sometimes choose the wrong items by mistake, or become frustrated when submenus pop up unnecessarily. This paper proposes two methods for improving the usability of cascading menus. The first uses the direction of cursor movement to change the menu behavior: horizontal motion opens/closes submenus, while vertical motion changes the highlight within the current menu. This feature can reduce cursor movement errors. The second causes a submenu to pop up at the position where horizontal motion occurs. This is expected to reduce the length of the movement path for menu traversal. A user study showed that our methods reduce menu selection times, shorten search path lengths, and prevent unexpected submenu appearance and disappearance.