webanywhere: a screen reader on-the-gowebinsight.cs.washington.edu/papers/sotg.pdf · collaborative...

WebAnywhere: A Screen Reader On-the-Go

Jeffrey P. Bigham and Craig M. PrinceDepartment of Computer Science and Engineering

University of WashingtonSeattle, WA 98195 USA

{jbigham|cmprince}@cs.washington.edu

ABSTRACTPeople often use computers other than their own to browsethe web, but blind web users are limited in where they ac-cess the web because they require specialized, expensive pro-grams for access. WebAnywhere is a web-based, self-voicingbrowser that enables blind web users to access the web fromalmost any computer that can produce sound. The systemruns entirely in standard web browsers and requires no ad-ditional software to be installed. The system could serveas a convenient, low-cost solution for both web developerstargeting accessible design and end users unable to afford afull screen reader. This demonstration will offer visitors theopportunity to try WebAnywhere and learn more about it.

Categories and Subject DescriptorsK.4.2 [Social Issues]: Assistive technologies for personswith disabilities; H.5.2 [Information Interfaces and Pre-sentation]: User Interfaces

General TermsDesign, Human Factors

Keywordsscreen reader, web accessibility, blind users

1. INTRODUCTIONPeople often use computers that are not their own. From

terminals in public libraries to the local gym, from cof-fee shops to pay-per-use computers at the airport, from afriend’s laptop to a school laboratory; computers are usedfor a variety of useful tasks that most of use take for granted,such as checking our email, viewing the bus schedule or find-ing a restaurant. Few would argue that the ease of use of webmail or document editors has surpassed desktop analogs, buttheir popularity is increasing, indicating the rising impor-tance of accessing the web from wherever someone happensto be. Blind web users lack the ability to access the webfrom all available computers because their access relies onexpensive, specialized software programs called screen read-ers. WebAnywhere is web application that can be accessedand used from any standard web browser.

Copyright is held by the author/owner(s).ASSETS’07, October 15–17, 2007, Tempe, Arizona, USA..ACM 978-1-59593-573-1/07/0010.

Figure 1: People often use computers other thantheir own, such as a computer in a university lab, akiosk at the local library, or even a friend’s laptop.

Traditional screen readers such as JAWS [2] or Window-Eyes [1] are expensive, special-purpose software programsand are seldom installed on public terminals or other com-puters not normally used by blind individuals. The Fire Voxscreen reader1 is a free Firefox extension, but is similarlyunlikely to be installed on most systems. Users are rarelygiven permission to install new software on public terminalsand many would be hesitant to install new software on afriend’s laptop. Scribd.com2 converts documents to speechfor free, but does not support interactive navigation of con-verted documents. Portable alternatives are quite costly.The Freedombox System Access Mobile3 screen reader ona USB key is available for nearly $500, but requires accessto a USB port and permission to run arbitrary executables.PDA solutions such as Braille Sense4 cost roughly $5000. Asmartphone with the screen reading software Mobile SpeakPocket5 costs about $1000. Many cannot afford or wouldprefer not to carry such an expensive device.

The WebAnywhere screen reader enables blind users toquickly access web content on any available computer andsupports a rich set of user interaction. Users can browsethrough the DOM of web pages viewed by paragraph, sen-tence, word or character. They can also quickly navigate

1www.firevox.clcworld.net/2www.scribd.com3www.freedombox.info/4www.gwmicro.com/Braille Sense/5www.codefactory.es/

between tab-indexed elements, heading element, form ele-ments and links using standard keyboard shortcuts. Forminput is also supported and does not require a separate formsmode. Because the system is web-based, it leverages existingfunctionality in standard web browsers.

WebAnywhere is also useful for web developers and blindusers who cannot afford a traditional screen reader. Mankoffet al. showed that web developers create more accessibleweb pages when they review them with a screen reader [5],and WebAnywhere provides a convenient, inexpensive mech-anism to do so. For blind users unable to afford a traditionalscreen reader, WebAnywhere might serve as a temporary al-ternative. Voice output while navigating through a page canalso be beneficial for people who have low vision or dyslexia.The technology introduced in WebAnywhere could providethis functionality anywhere.

2. SYSTEM DESIGN & EVALUATIONThe design of WebAnywhere is similar to a traditional

screen reader. It differs because it moves some operations toa remote server and includes functionality designed to com-pensate for web application limitations. The system consistsof the following three components: 1) client-side Javascriptthat supports user interaction, determines which sounds toplay and coordinates the other subsystems, 2) server-sidetext-to-speech generation and caching, and 3) a server-sidereverse-proxy that makes web pages appear to come froma local server to overcome cross-site scripting restrictions.The system plays sounds using the SoundManager 2 FlashObject6. Adobe reports that 98.7% of desktops have Flashinstalled7. WebAnywhere also supports embedded soundplayers for increased compatibility. WebAnywhere’s use ofJavascript to capture a rich set of user interaction is similarto that of UsaProxy [3] and Google Analytics8. A diagramof the system is shown at the top of this page.

If the browser window containing WebAnywhere loses fo-cus, the system is unable to respond to user input. Web-Anywhere attempts to prevent losing focus by aggressivelyblocking popup windows and page redirects that do not gothrough the reverse proxy. In the event that focus is lost,users can switch through applications (Alt-Tab on most sys-tems) until WebAnywhere receives focus and announces it-self. The latency of retrieving each new multi-second soundis roughly 500 ms and prefetching sounds improves this byabout 20%. Cached sounds are retrieved immediately.

WebAnywhere has been developed with consultation of

6www.schillmania.com/projects/soundmanager2/7www.adobe.com/products/player census/flashplayer/8www.google.com/analytics

blind web users. These potential users have been overwhelm-ingly enthusiastic about the system. In an informal evalua-tion, three blind participants (1 female, 2 remotely-located),could effectively browse the web using WebAnywhere. Dur-ing this evaluation, we first outlined the available featuresof the WebAnywhere system and then explained the avail-able functionality and shortcut keys. We then asked ourparticipants to visit the google.com search page, submit aquery and read the results. All of our participants were ableto successfully complete this task with only limited verbalcoaching. Our participants listed the lack of the full screenreader functionality as the main limitation of the system.Notably, no one mentioned latency concerns and all thoughtthe responsiveness of the system was adequate. During ad-ditional unstructured browsing, the WebAnywhere windowoccasionally lost focus due to unblocked popups, but partic-ipants independently returned to the WebAnywhere.

Future versions of WebAnywhere will implement morefeatures offered by commercially-available screen readers.Users that evaluated our system requested support for keycombinations specific to either JAWS or Window-Eyes andwe will provide such customized modes. We also plan to addsupport for browsing secure sites and support for accessibil-ity improvement using our Accessmonkey Framework [4].

3. REFERENCES[1] GW Micro Window-Eyes, 2006.

http://www.gwmicro.com/Window-Eyes/.

[2] JAWS 8.0 for windows. Freedom Scientific, 2006.http://www.freedomscientific.com.

[3] R. Atterer, M. Wnuk, and A. Schmidt. Knowing theuser’s every move - user activity tracking for websiteusability evaluation and implicit interaction. In Proc.of the 15th Intl. Conf. on World Wide Web (WWW’06), pages 203–212, 2006.

[4] J. P. Bigham and R. E. Ladner. Accessmonkey: Acollaborative scripting framework for web users anddevelopers. In Proc. of the Intl. Cross-DisciplinaryConf. on Web Accessibility (W4A ’07), 2007.

[5] J. Mankoff, H. Fait, and T. Tran. Is your web pageaccessible?: a comparative study of methods forassessing web page accessibility for the blind. In Proc.of the SIGCHI Conf. on Human Factors in ComputingSystems (CHI ’05), pages 41–50, 2005.