why browser zoom for low vision users
DESCRIPTION
SUCKS. Why Browser Zoom For Low Vision Users. Denis Boudreau Deque Systems, Inc. [email protected] @dboudreau. Wayne Dick CSU Long Beach waynedick @ knowbility.org. An production. It all started with this. Or rather, this… (200%). Actually, maybe even this… (300%). - PowerPoint PPT PresentationTRANSCRIPT
Denis BoudreauDeque Systems, Inc.
[email protected]@dboudreau
Why Browser Zoom
For Low Vision UsersSUCKS
An <a11yRant/> production.
Wayne DickCSU Long [email protected]
It all started with this.
Or rather, this… (200%)
Actually, maybe even this… (300%)
But more specifically, THIS.
No, not
THAT KIND
of agnosticism,
but rather…
Thomas Henry Huxley (1869)
Leading to heated internal debates
Browser Zoom!Text Resize!
Why BOTHER
with SC 1.4.4 if it
NEVER FAILS!
Web Developers vs. End Users
Web Developers vs. End Users
What Web Developers Want
Easy SolutionsReliable TestingMeasurable
Results
Browser Zoom
Web Developers vs. End Users
What Web Developers Want
Easy SolutionsReliable TestingMeasurable
Results
Browser Zoom
VS.What Low VisionUsers Expect
Robust SolutionsAdaptive InterfacesUsable Content
Text Resize
WHO estimates 285 million visually impaired people worldwide.39 million are blind. 246 have low vision (7.3x as many).
As opposed to the United States population…
Or even Canada’s!
Our job is not to go easy on developers who should know better, but to help foster digital equality for everyone.
Browser Zoom Only Testing
IS POINTLESS
for HTML Accessibility
Browser Zoom Only Testing
IS POINTLESS
for HTML Accessibility
»»» So what about the end users???
Web Developers vs. End Users
Visual Concepts
Acuity LimitCritical Print Size (CPS)Feasible Print RangeCost + Technology +Reader Preference => CPSTo read you need CPS + Word Wrapping
Image of graph of reading speed (vertical) by font size (horizontal)… very simplified.
Is Zoom bad for Everything?
NO!Zoom is great for spot work near the acuity limitSmall Control forms can be zoomed and operatedZoom just fails for reading.The reason follows
Why?
Enlarged content presented for users with full sight is not the same as content presented for users with compromised sight.
Specifically
Lack of word wrapping creates semantic discontinuity
Discontinuity creates data loss and noise Now let’s quantify the data loss and noise
Figure1:A Simple Text Standard Print
Figure 2:Same Text Zoomed with NO Reflow
Same Text Enlarged WITH Reflow
Counting Words
Figure 1: 113 words
Figure 2: 36 words (counting partial words)
Figure 3: 35 words
At a glance, Figure 2 looks as efficient as
Figure 3
Continuity
• Figure 1 (standard print) and Figure 3 (large
print wrapped) present contiguous data.
• In of the language in the essay the first word of
each line is the immediate successor of the last
word on the preceding line.
• This is true for Figure 1 and Figure 3 even
though Figure 1 has 3 times the words.
• Even though Figure 3 reduces the quantity of
data every word on the page is useful.
Discontinuity and Noise
• Lines are not connected in Figure 2 (Zoom NO Wrap).
• Consider the highlighted line, “Screen magnifier
users may.”
• The last visible preceding word is truncated “assisti”
• Between “assisti” and “Screen” are four words and
“ve”, the tail of “assistive”.
• This means on line has any real meaning.
• The rest are noise
Data Loss
• In the first and third figure there is no noise.
• In Figure 2 (NO Wrap). – Looking at the highlighted line (the signal) we have 4 words
– The remainder the disjoint lines, words we have 32 words
– Thus only 1 in for words on this view port have meaning as
we read the highlighted line.
• Figure 3 has 35 words, Figure 2 has 36 but
• Every word on the Figure 3 (WITH Wrap) viewport is
useful
• Only 1/8 are useful in Figure 2 (NO Wrap)
The Burning Question?
• Is zoom without reflow a functional
tool for reading?
• Is screen magnification reasonable
accommodation?
• Does screen magnification constitute
accessibility support for WCAG 2.0
criteria?
Open Discussion
Thinking RWD
Web Developers vs. End Users
Bake SC 1.4.4 straight into your CSS
Thank you!
Photo Creditshttp://gigaom2.files.wordpress.com/2012/08/shutterstock_97220924.jpg http://udemand.files.wordpress.com/2012/07/14.jpg http://taoofman.com/wp-content/uploads/2012/06/ToM_EnsoCircle.png http://www.information.dk/sites/information.dk/files/media/2009/05/01/20090501-174730-pic-363902257.jpg http://www.namespedia.com/image/Huxley_2.jpg http://www.flickr.com/photos/xurble/196294004/ http://free-illustrations-ls01.gatag.net/images/lgi01a201309211700.jpg http://www.flickr.com/photos/kingdesignchile/9023900039/ http://ministry127.com/sites/default/files/Avoiding%20the%20Traps%20of%20the%20Teen%20Years-blank.jpg http://www.sciculture.ac.uk/files/2013/12/Ignite-Event-Image-2.jpg http://www.abortionmemorial.com/wp-content/uploads/2013/07/blurred-vision.jpg