w4a2015 - tpg accessibility challenge
TRANSCRIPT
A Controlled-Language Checker Turned into
an Accessibility Evaluation Tool for
Image Text Alternatives
Silvia Rodríguez Vázquez
Sabine Lehmann
The Paciello Group Accessibility Challenge
W4A 2015, Florence, Italy, 18-20 May 2’015
Image accessibility
Use of the alt attribute of the HTML <img> element
Examples from Faulkner, S. (ed.) 2014. HTML5: Techniques for
providing useful text alternatives. W3C Working Draft.
Image accessibility
Use of the alt attribute of the HTML <img> element
Examples from Faulkner, S. (ed.) 2014. HTML5: Techniques for
providing useful text alternatives. W3C Working Draft.
Our proposal
Rule set design
Data generation method: documents
Literature review on how to write text
alternatives for images
Swiss case study
Main goal:
Propose a French controlled-language (CL)-based
automated solution for text alternatives authoring
and verification
Reduced sample of 52/100 websites
1,938 webpages
Total <img>
No alt
Empty alt
Non-empty
altInitial set
50,633 9,241 12,238 29,154
Filtered set
12,778 1,267 3,566 7,945
Linguistic patterns frequently used in
appropriate and non-appropriate
text alternatives for images
Rule set for alt text verification
Type of
content
#
rules
Example Non appropriate
alt
Appropriate
alt
Descriptive 14 Avoid redundant
expression “ “image””(e.g., ‘image de,
image répresentant,
sur cette image on
voit…...…)
Sur cette image:
Eloise avec la
princesse Belle
Eloise avec la
princesse Belle
Functional 18 Describe actions
related to social
media and mailing
appropriately
Flux RSS S’’’’'abonner aux
flux RSS de la
Tribune de
Genève
Uninformative 8 Avoid using
placeholders
Insérer le texte ici alt=“""
Acrolinx GUI
Rule documentation
Rule documentation
Integration with CAT*
tools for translators
Practical applications
*Computer Assisted Translation
Advantages:
Language and rule
customization
Interactive rule
application
Integration with WAE tools for developers and
other content authors
Practical applications
Practical applications
*Huang, Ting-Hao K. Alt Text Editor. Computer software. Alt Text Editor. Vers. 1. N.p., 25 Feb.
2015. Web. Class project of the "Web Accessibility" class (05-897 A3) at Carnegie Mellon
University: https://www.legionpowered.net/Chorus_Sessions/Chorus/AltText/
