A Web Design Framework for Improved Accessibility for People with Disabilities (WDFAD)

A Web Design Framework for Improved Accessibility for People with Disabilities (WDFAD) By Rehema Baguma & Jude Lubega (Makerere University, Uganda)

Introduction

WWW is progressively becoming indispensable

PWDs can conveniently undertake tasks that would be difficult or impossible

But this is only possible on accessible websites

Guidelines that guide on developing accessible websites exist

But many websites are still not accessible, Why?

Majority are difficult to integrate into existing developer workflows and rarely offer specific suggestions that are developer oriented (Bigham & Ladner, 2007)

The WDFAD –approach for presenting guidelines into a precise & web developer oriented format

Packed according to the three components of WAs; content, navigation and user interface

Presents Web access. requirements as primary goals and sub goals

Shows relationship btn primary goals in relation to sub goals, identifies critical sub goals and suggestions on general application of the framework

Web Appl. Components & Web Accessibility

A WA- an application in which all or some parts are downloaded from the Web each time it runs.

WA comprises of content, navigation and user interface.

Content

Navigation (traveling between/with in a page)

User interface

Some issues that influence content accessibility also influence navigation & user interface accessibility

Certain Web design considerations can make the Web accessible PWDs like the blind e.g;

text alternative for every visual element

meaningful content structure in the source code

provision for skip navigation

Descriptive titles for web pages/links and headings in relation to their purpose etc.

However it is yet to be known how the given Web accessibility design requirements relate to the different components of Web applications.

Table 1 shows a classification of the requirements according to the three components of Web applications

based on the description of what comprises content, navigation and user interface

Purpose is to highlight the relationship between Web; content, navigation and the user interface in relation to Web accessibility for PWDs such as the blind

Table 1. A Classification of the Web Accessibility Requirements for the Blind according to the three components of Web applications Web Accessibility Requirement Affected Web component if not met during design Content Navigation User Interface Text only version of entire website yes yes yes Text alternative for every visual element yes Yes yes Synchronized text alternatives for video accompanied by interaction no no yes Meaningful content structure in the source code yes yes yes Provision skip navigation no yes no Descriptive titles for web pages, links and headings in relation to their purpose no yes yes Divide long pieces of content into sections with section headings no yes yes Make Web pages appear and operate in predictable ways no yes yes Help users avoid and correct input mistakes yes no yes Design for device independence yes yes yes Accessible tables yes yes no Accessible frames or no frame content no yes yes Presentation of form based content in a logical sequence no no yes Test the application with keyboard only access no yes yes Use or convert documents into standard formats yes no Yes Expand abbreviations and acronyms the first time they appear on a page yes no no

Are all the requirement really necessary for the accessibility of the related Web component?

What about assistive technology (AT)?

Assistive technologies used by the blind

Software or hardware specifically designed to support PWDs in carrying out daily activities

ATs for the blind provide sight substitution mechanisms for computer and Web access

The blind require non-visual alternatives for traditionally visual tasks

e.gs of ATs; screen readers , voice browsers, sensory keyboards

In accessible web designs pose challenges to AT users

e.g. with images, video, tables, forms

Table 2 gives a summary of how each requirement makes a difference

Table 1. Summary Justification for the Web Accessibility Requirements Requirement Justification Content Navigation User Interface Text only version of entire website 1 ATs can only read & relay content in text form ATs can only read & relay navigational elements in text form ATs can only perceive and relay intelligibly interface elements in text form Text alternative for every visual element ATs can only read and relay content in text form ATs can only read and relay navigational elements in text form ATs can only relay intelligibly interface elements in text form Synchronized text alternatives for synchronized video Not applicable Not applicable Users can synchronously perform associated interactive tasks Meaningful content structure in the source code Adds a layer of meaning enhancing ATs to read & interpret documents to users Time saving with navigation. ATs read Web pages in serial order Time saving with user interface tasks. ATs ,read’ Web pages in serial order Accessible Tables (data and layout) ATs need to know which cell has header or title info for any given data cell ATs need to relay lay out tables into a usable form for the user Not Applicable Accessible frames or no frame content ( 2 see end of table for definition) Not applicable Facilitates frame identification and navigation with ATs. Facilitates frame identification and access to its elements by ATs. Presentation of form based content in a logical sequence Not applicable Not applicable Helps ATs understand & relay forms & their elements in usable formats Use or convert documents into standard formats Makes documents compatible with ATs Not Applicable Makes documents perceivable with ATs Expand abbreviations and acronyms the first time they appear Enables ATs to provide their full meaning to users Not Applicable Not Applicable Provision for skip navigation Not Applicable Users can skip certain content e.g. adverts to main content Not Applicable Descriptive titles for web pages, links &headings in relation to their purpose Not Applicable For quicker user orientation within the site Users can more quickly identify the parts they need Divide long pieces of content into sections with section headings Not Applicable Users can move from heading to heading, to find quickly content of interest Users will know when they have moved from one section to another & the purpose of each section Make Web pages appear and operate in predictable ways Not Applicable Users can quickly form a mental image of the site Having mental image of the site makes web pages easy to use Help users avoid and correct input mistakes Users will be able to supply the required information Not Applicable Interactive components will be more user friendly Design for device independence Makes pages compatible with ATs Makes pages compatible with ATs Makes pages compatible with ATs Test application with keyboard only access Not Applicable Keyboard is the primary navigational device for the blind Keyboard is the primary input device for the blind

Web Design Framework for Improved Accessibility for People with Disabilities (WDFAD)

An approach for presenting guidelines into precise & Web developer oriented format

Packaged according to the three components of Web applications

Presents Web acc. requirements as pr. goals & sub goals that must be achieved during Web development

Using constructs of NFR framework (Chung & Nixon, 1995)

Pr. goals represent high level acc.design objectives;

to make content, navigation & user interface accessible

Sub goals represent the requirements that must be met in Web design to meet each primary goal

text alternative for visual elements makes images & video (content) accessible

Shows relationships btn pr. goals & sub goals with a justification

Identifies critical sub goals- those shared by all the pr.goals

Figure 1: Primary goals of Web Accessibility for PWDs WDFAD User interface Accessibility Navigation Accessibility Content Accessibility

Figure 2: The Relationship between Web accessibility Requirements and Components of Web Applications/WDFAD E F C-User interface accessibility primary goal A-Content Accessibility primary goal B-Navigational Accessibility primary goal G D

Description and Discussion of WDFAD

WDFAD is presented as a Venn diagram in figure 2 with three sets

Each set corresponds to a primary goal and contains the related sub goals for Web accessibility

|A|=8|

B|=11

|C|=13

D,E,F are the shared sub goals

|D|= 4

|E|=1

|F|=2

|G|=5

D represents the critical sub goals

Distribution of sub goals shows UI with the most & content with the least

Can this be translated into design demands?

Web 2.0 has refocused Web into a more interactive medium

Accessibility too needs refocus - a not easy venture but efforts under way

WCAG 2.0 draft has many guidelines and techniques on making interactive tasks accessible.

We categorize members of D as the most critical sub goals due to their global effect among primary goals e.g. Alt text for visual elements

Navigation and UI share the most sub goals

Accessibility or lack of it for navigation or UI affects more the other than it does to content

Other important observation;

There are more shared sub goals than individual goals

|D|+|E|+|F|+|G| > ((A B U C) + (BA U C) + (CA U B ))

Hence the three components have a lot in common that can be exploited to the benefit of the Web acc. process

WDFAD could make Web access. guidelines easier to understand and apply by Web developers.

Precise & packaged according to universal concepts about Web applications

Preciseness is important because developers are used to communicating in formal instructions.

Familiar tools can be easily understood &assimilated given the demanding work life of developers.

The global versus local classification modularizes the guidelines for easier understanding, application & update

Existing guidelines could be simplified by adopting such a categorization e.g ;

global (content, navigation and user interface), global (content and navigation), global (content and user interface) and global (navigation and user interface).

or according to the types of disabilities that affect a person’s use of the Web.

Conclusion & Future Work

In this paper we have presented a Web Design Framework for Improved Accessibility for People with Disabilities (WDFAD)

An approach for presenting guidelines into precise & a Web developer familiar classification

It is hoped that application of the WDFAD concept to Web access. guidelines could make them easier to understand and apply by Web developers

Thank you for your time

Your Comments & Questions are Welcome

A Web Design Framework for Improved Accessibility for People with Disabilities (WDFAD)

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