accessibility studies and sizes

This page looks at writing about accessibility problems, standards and issues.

It covers -

• writing about issues and standards
• economics, security and the business case for accessibility
• implementation
• devices and questions about monitor sizes
• connections

     writing

Jakob Nielsen's Designing Web Usability: The Practice of Simplicity (Indianapolis: New Riders 1999) and online Alertbox newsletter are strongly recommended. He has drawn together many of the issues in an article on Disabled Accessibility: The Pragmatic Approach.

Nielsen's Usability Engineering (New York: Academic Press 1993) is somewhat more demanding but draws on extensive empirical studies in discussing principles and practice.

Ben Schneiderman's Designing The User Interface: Strategies for Effective Human-Computer Interaction (Reading: Addison-Wesley 1998) is excellent. It is supported by a companion site.

Yale University's masterful Web Style Guide: Basic Design Principles for Creating Web Sites (New Haven: Yale Uni Press 1999) by Patrick Lynch & Sarah Horton is also recommended; there is an online version that is both informative and a minor work of art. It complements Nielsen and has a practical approach to the use of Cascading Style Sheets (CSS). A broader perspective is provided by the excellent Columbia Guide To Digital Publishing (New York: Columbia Uni Press 2003) edited by William Kasdorf.

The Design guide elsewhere on this site points to other works, such as Cooper's classic About Face: The Essentials of User Interface Design, Raskin's The Humane Interface: New Directions for Designing Interactive Systems and Advances in Universal Web Design & Evaluation: Research, Trends & Opportunities (Hershey: IDEA Group 2007) edited by Sri Kurniawan & Panayiotis Zaphiris.

Web Site Usability: A Designer's Guide by Jared Spool, T DeAngelo & others (New York: Academic Press 1998) and Web Accessibility for People With Disabilities (Lawrence: CMP 2000) by Michael Paciello are recommended.

Other sources worthy of investigation are the Usable Web site and the resources on the Usability Professionals' Association (UPA) site. The Bad Designs site offers offline points of reference.

US disability engineering expert Jon Gunderson has explored World Wide Web Browser Access Recommendations as part of his work on MOSAIC and has a paper on World Wide Web Accessibility to People with Disabilitities: A Usability Perspective.

Donald Case's broader Looking for Information: A Survey of Research on Information Seeking, Needs, and Behavior (New York: Academic Press 2002) is commended. Other resources about information seeking are highlighted here and here. The 2006
US National Council on Disability paper Over the Horizon: Potential Impact of Emerging Trends in Information and Communication Technology on Disability Policy and Practice offers perspectives on potential future accessibility challenges.

     economics, security and business cases

For introductions to the 'case for usability' see in particular The Politics of Usability: A Practical Guide to Designing Usable Systems in Industry (London: Springer-Verlag 1998) edited by Lesley Trenner & Joanna Bawa and Cost-Justifying Usability (New York: Academic 1994) edited by Randolph Bias & Deborah Mayhew. Security and Usability (Sebastopol: O'Reilly 2005) edited by Lorrie Cranor & Simson Garfinkel is of particular value.

We've highlighted works and issues regarding the politics of accessibility on the final page of this guide.

     implementation

Perspectives on systematising accessible design are provided in Institutionalization of Usability: A Step-by-Step Guide (Reading: Addison-Wesley 2004) by Eric Schaffer.

     devices

Statistics about the devices with which people access online content are problematical.

The July 2001 WebSideStory survey claimed that the most common screen resolution was 800 x 600 pixels. Subsequent reports from WebSideStory and other sources suggest that there was a slow change, with 800 x 600 being surpassed as the dominant screen resolution worldwide in April 2003.

WebSideStory claimed in August 2003 that 58% of web users used a screen resolution of 1024 x 768 or higher, up from 34% in January 2000 and 20% in January 1999. The number viewing with 640 x 480 is claimed to have fallen to 5.71% from 17.83%; the 1152 x 864 and 1280 x 1024 sizes have shown small gains since 1999 and now account for around 5% of the market.

There is however significant national/regional variation, which may reflect data sources.

Globally the figures as of mid 2002 were claimed to be -

2.3% of the online population uses a 1152 x 864 monitor
2.9% uses 1280 x 1024
32.7% uses 1024 x 768
52.5% uses 800 x 600
5.7% uses 640 x 480

Most people are continuing to rely on desktop monitors and laptops rather than PDAs or mobile phones.

     connections

Accessibility challenges are not restricted to physical disadvantage (eg poor sight or motor impairment). They also encompass geographical location and economic disadvantage, eg trying to access online content via a slow connection in remote Australia.

Statistics about the online population feature in the Metrics & Statistics guide, supported by a more detailed examination of Australian and international Digital Divides. Background about Australia's telecommunications infrastructure is here.

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