Susan Crayne

Improving web accessibility through an enhanced open-source browser

The accessibilityWorks project provides software enhancements to the MozillaTM, Web browser and allows users to control their browsing environment. Although Web accessibility standards specify markup that must be incorporated for Web pages to be accessible, these standards do not ensure a good experience for all Web users. This paper discusses user controls that facilitate a number of adaptations that can greatly increase the usability of Web pages for a diverse population of users. In addition to transformations that change page presentation, innovations are discussed that enable mouse and keyboard input correction as well as vision-based control for users unable to use their hands for computer input.

Personalization of Web browsing: adaptations to meet the needs of older adults

Despite difficulties in using the Web, older adults are motivated to use it. This paper reports on work underway to ease Web access for this population. Although Web accessibility standards provide specifications that Web content providers must incorporate if their pages are to be accessible, these standards do not guarantee a good experience for all Web users. This paper will discuss user controls that make a number of dynamic adaptations to page presentation and input that can greatly increase the usability of Web pages for older users. The paper will discuss the authors’ original work on the topic, lessons learned, and usage patterns. Current extensions to that work are also discussed.

Visualizing motion in video

In this paper, we present a visualization system and method for measuring, inspecting and analyzing motion in video. Starting from a simple motion video, the system creates a still image representation which we call a digital strobe photograph. Similar to visualization techniques used in conventional film photography to capture high-speed motion using strobe lamps or very fast shutters, and to capture time-lapse motion where the shutter is left open, this methodology creates a single image showing the motion of one or a small number of objects over time. Based on digital background subtraction, we assume that the background is stationary or at most slowing changing and that the camera position is fixed. The method is capable of displaying the motion based on a parameter indicating the time step between successive movements. It can also overcome problems of visualizing movement that is obscured by previous movements. The method is used in an educational software tool for children to measure and analyze various motions. Examples are given using simple physical objects such as balls and pendulums, astronomical events such as the path of the stars around the north pole at night, or the different types of locomotion used by snakes.

Accessibility works: enhancing web accessibility in Firefox

This paper reviews several techniques we have discovered while trying to extend the Firefox browser to support people with visual, motor, reading, and cognitive disabilities. Our goal throughout has been to find ways to make on-the-fly transformations of Web content including adjustments of text and image size, text style, line and letter spacing, text foreground color, text background color, page background removal, content linearization, and reading text aloud. In this paper, we focus primarily on the changes we make to the browsers Document Object Model (DOM) to transform Web content. We review the kinds of approaches we have used to make DOM modifications sufficiently fast and error free. We highlight the problems posed by Web pages with a mix of static and dynamic content generated by client-side scripts and by Web pages that use both fixed and relative placement of page elements, pages of the sort we expect to see in increasingly in the future.