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Raphael Clegg-Vinell, Chris Bailey, Voula Gkatzidou.AbilityNet.
Email: [email protected] [email protected]
Twitter: @Raphael_CV; @chrisbailey000; @vouloula
Investigating the Appropriateness and Relevance of Mobile Web Accessibility Guidelines
The Overall Problem
“We haven’t solved the problem of web accessibility”
- Jeff Bigham, W4A 2013.
A New Problem
Mobile Accessibility:
Small Screens
Environmental Factors
Multiple, minor impairments
Mobile Accessibility
Increasing importance to understand accessibility of mobile web content (Carrico et al, 2011).
Clients request WCAG 2.0 and MWBP 1.0 CR for internal ‘sign off’.
Important for guiding developers in developing to support accessibility (Kelly et al, 2007).
Lack of evaluation support tools for WCAG 2.0 and MWBP on mobile devices.
User Testing Sessions
User testing is often requested as a supplement or replacement for expert reviews.
Research supports this approach:
Developers should obtain severity ratings from users or an expert rather than relying on those provided by guidelines (Harrison & Petrie, 2006).
The severity of an issue cannot be accurately rated without contextualising the circumstances under which the problem occurs. Contextual considerations include what the potential barrier is, the type of user affected and what their browsing capabilities are (Brajnik, 2008).
Testing Methodology
Data taken from results of 5 mobile testing sessions.
Participants:
Dyslexia
Deaf (BSL)
Low Vision
Mobile Screen Reader User
Older User
Attention/Memory
6 – 8 tasks
60 – 90 minute session.
Determining the Severity of Issues
The three factors to determine the severity rating:
The frequency with which the problem occurs (number of users).
The impact of the problem if it occurs.
The persistence of the problem.
– Nielsen, J.
Typical Issues
Case Study – Mapping Issues to Guidelines
Banding issues into three categories:
1. Issues which clearly correspond to guidelines under WCAG and or MWBP 1.0.
2. Issues which cannot be easily associated to guidelines under WCAG 2.0 or MWBP 1.0 without expert interpretation from an experienced consultant or developer.
3. Issues which do not fall under WCAG 2.0 or MWBP 1.0 but still cause a significant accessibility barrier.
1. Issues which Clearly Correspond to Guidelines
Users frequently reported issues relating to colour contrast. Clearly corresponds to:
WCAG 2.0 AA 1.4.3 Contrast
MWBP 1.0 [COLOR CONTRAST]
Success Criteria 1.4.3 Contrast (Minimum) is an AA issue – we reported this as High Priority.
Colour contrast is persistent, high frequency, high impact.
2. Issues which Require Expert Interpretation
Finger pinch zoom gestures where text or icons were too small to read or identify.
MWBP 1.0 [CAPABILITIES]
“Exploit device capabilities to provide an enhanced user experience”
WCAG 2.0 AA Success Criteria 1.4.4 Resize Text:
“text can be resized without assistive technology up to 200 percent without loss of content or functionality”.
2. Issues which require Expert Interpretation
Interface elements do not receive focus of screen reader:
MWBP 1.0 [TAB ORDER]:
Create a logical order through links, form controls and objects.
WCAG 2.0 AA 2.1.1 Keyboard:
All functionality of the content is operable through a keyboard interface.
3. Issues which do not Fall Under WCAG 2.0 or MWBP 1.0
Several instances reported of icons which users did not understand the purpose of.
“Dialogues should not contain information which is irrelevant or rarely needed. Every extra unit of information in a dialogue competes with the relevant units of information and diminishes their relative visibility”
– Nielsen, J.
No minimum size requirements for text or icons under WCAG 2.0 or MWBP 1.0.
Conclusion
Our results have shown some issues clearly relate to checkpoints in WCAG 2.0 and MWBP 1.0.
Our findings show that it common issues do not easily relate to guidelines may not be considered not reliably testable.
“We also claim that it is not necessary to assess all MWBP guidelines and that its eligibility for Web content evaluation depends on usage preferences”
- Carriço, L., Lopez, R. and Bandeira
In mobile context, users could be the gold standard.
Future Work
Continue collating the issues raised by our testers.
Monitor and compare severity ratings.
Categorise and classify accessibility issues according to disability types; compare to other studies (Carrico et al, 2011).
Develop Mobile Accessibility principles:
Design: Text Size; Icon Labelling.
Interaction: Target Size; Element Spacing
Structural: [STRUCTURE] Use features of the markup language to indicate logical document structure.
Technical: [REDIRECTION] Do not use markup to redirect pages automatically.
Raphael Clegg-Vinell, Chris Bailey, Voula Gkatzidou.AbilityNet.
Email: [email protected] [email protected]
Twitter: @Raphael_CV; @chrisbailey000; @vouloula
Investigating the Appropriateness and Relevance of Mobile Web Accessibility Guidelines
