W3C logoWeb Accessibility Initiative (WAI) logo

WAI: Strategies, guidelines, resources to make the Web accessible to people with disabilities

Site Navigation: W3C Home > WAI Home > Web Content Accessibility and Mobile Web

Shawn notes on:
Shared Web Experiences: Barriers Common to Mobile Device Users and People with Disabilities (Topic format)
[Editors' Draft, 31 July 2008]

The main content in this document is organized in topic sections.
The same information is also available in a table format.


Below are notes from Shawn, proceeded with SLH: and ending in ]]

Status: This document is an in-progress Editor's Draft. The published version is at www.w3.org/WAI/mobile/experiences-format.
Please send comments to wai-eo-editors@w3.org (a publicly archived list).

People with disabilities (using desktop or laptop computers) and people without disabilities who are using mobile devices have similar interaction limitations and they experience similar barriers when interacting with Web sites. There is also significant overlap between the design solutions for both. For more information, see:

This page provides examples of barriers to interacting with Web content experienced by people with disabilities and people using mobile devices. SLH: Could make this more active: "This page provides examples of barriers that people with disabilities and people using mobile devices experience when interacting with Web content."]] Mobile devices vary widely and not all the problems are present on all models. These barriers are grouped under four principles: perceivable, operable, understandable and robust. These principles lay the foundation necessary for anyone to access and use Web content, as described in Understanding the Four Principles of Accessibility section of Introduction to Understanding WCAG 2.0.

This page also includes links to some relevant solutions in:


The text is short and succinct, which is nice; however, it's not always clear. I think we want to say just a little more in some places, to make it more clear.


Information and user interface components must be presentable to users in ways they can perceive.

Information conveyed using color SLH: Need to add the rest of this that is in the table version (otherwise they are not equivalent)]]

SLH: I think these sentences need context and suggest adding the heading that is in the table version: "Experience:"]] User perceives color incorrectly or not at all, and so misunderstands information, makes mistakes, or misses information. SLH: perhaps put "misses information" first in the list since it is both most common and most important]]

Disabilities Context: User who is blind or colorblind perceives color incorrectly or not at all.

Mobile Context: Many screens have limited color palette and color difference is not presented. Device is often used in poor lighting (for example, outdoors) and because of the glare, colors are not clearly perceived.

top contents list

Large page or large images SLH: what about breaking up "large page" and "large images" in to two different items?]]

User only sees small areas at a time ("keyhole view") or cannot access picture details because they are shrunk, unable to relate different areas of page, becomes disoriented or has to scroll excessively. SLH: needs some editing to be more clear]]

Disabilities Context: User with restricted field of vision or using screen magnifier get only small part of page or image at a time.

Mobile Context: Mobile device has small screen (viewport).

SLH: error in the code above - before SCROLLING is </li><>li>]]

top contents list

Multimedia with no captions

User misses auditory information.

Disabilities Context: User who is deaf or hard of hearing can't hear.

Mobile Context: Mobile users often turn off sound in public places (trains, hotel lobbies) SLH: perhaps add "meetings"? <grin>]] or cannot hear in noisy places (streets, nightclubs).. SLH: two periods]]

top contents list

Audio-only prompts (beeps, buzzes) for important information (warnings, errors)

Can't operate or interact correctly with content, misses prompts, makes mistakes.

Disabilities Context: User who is deaf or hard of hearing can't perceive content.

Mobile Context: Users often cannot hear in noisy (street, nightclub) or in public places (trains, hotel lobbies).

top contents list

Free-text entry (for example, alphabetical characters allowed in numeric fields)

User enters text incorrectly, makes mistakes.

Disabilities Context: User with motor disability (partial paralysis, hand tremor, lack of sensitivity, coordination) has difficulty entering information. SLH: Please add "for example," at the beginning of the parenthesis so it's clear that this is not an inclusive list.]]

Mobile Context: Device has small keypad, or is held in unsteady hand. SLH: consider adding 'an' to "...or is held in an unsteady hand" to make it read more smoothly.]]

top contents list

Embedded non-text objects (images, sound, video) with no text alternative

Information loss due to lack of alternative. User can't perceive information.

Disabilities Context: User who is blind or color blind can't perceive content. SLH: I'm missing why this is a significant issue for people who are color blind, given that color contrast and redundant coding is covered elsewhere.]] Information not available to user whose user agent doesn't support object SLH: suggest: "...not available to user whose browser, assistive technology, other user agent doesn't...]] or with slow connection making it unreasonable to wait for download. SLH: Why is slow connection a particular disability issue? (Sure people with disabilities may have slower connections than average given lower employment and income; however, I don't think we want to get into that in this document.]]

Mobile Context: User with low bandwidth or who declines to run up connection charges. Already small images re-dimensioned even smaller in adaptation, become meaningless.

top contents list

Important information in non-text content (images, multimedia, CSS effects)

User misses important information.

Disabilities Context: Blind or color blind users can't perceive non-text content. SLH: I'm missing why this is a significant issue for people who are color blind, given that color contrast and redundant coding is covered elsewhere.]] They might use alternative style-sheets and not be able to access important information encoded in non-text content. SLH: suggest: "style sheets (CSS)" without a hyphen.]] SLH: Do you mean "encoded" or more simply "presented" or perhaps both?]] SLH: Could you take another pass at wording this one. It's not really clear. Or maybe it needs to be broken up... or maybe one of the issues is that is seems like some of it is already covered in other one points above?]]

Mobile Context: User billed for download volume, turns off images to save costs. SLH: This one is worded differently than ones above.]] Device has no CSS support.

top contents list

Content formatted using tables or CSS, and reading order not correct when linearized (for example when CSS or tables not rendered)

Content is garbled.

Disabilities Context: Non-visual (screen reader) user reads content in document tree order. SLH: This one is worded differently than ones above - "Non-visual (screen reader) user" here and "User who is blind" above.]]

Mobile Context: Meaning of content altered by reformatting or restructuring in adaptation process.

top contents list

Information conveyed only using CSS (visual formatting)

Information lost or altered.

Disabilities Context: Blind user doesn't perceive visual formatting effects. SLH: change "Blind user" to "User who is blind"]]

Mobile Context: Often no CSS support or diverging CSS support by mobile browser. SLH: Is there a better word that "diverging"? Perhaps "different" or "inconsistent" or even "incorrect'?]]

top contents list


User interface components and navigation must be operable.

Interaction and navigation requires mouse

User is unable to navigate all content, or wastes time moving through numerous links.

Disabilities Context: User with a motor disability may not be able to use a mouse. SLH: Suggestion: "Some users with a motor disability cannot use a mouse." Also, add people who are blind do not use the mouse.]]

Mobile Context: Device has no mouse, only alphanumeric keypad or rocker switch.

top contents list

Scripting required to operate or generate content

Information loss. Content inoperable.

Disabilities Context: User's assistive technology or browser doesn't support scripting.

Mobile Context: Scripting turned off or not supported.

top contents list

Special plugin required

User can not perceive content or can not operate interface.

Disabilities Context: Plugin turned off, not installed, not compatible with assistive technology. SLH: add 'or' in: "...not installed, or not compatible with...]] Plugin not operable with preferred input device.

Mobile Context: Plugin turned off or not installed; not compatible with input device (for example, requires mouse).

top contents list

Long page title, with generic information first and differentiating information last

SLH: What about missing title all together, and inappropriate title?]]

User has difficulty reading list, misses important information at end of title. SLH: need to explain "has difficulty reading list more here, or maybe better to leave it off here and explain more under 'Disabilities Content'?]]

Disabilities Context: Page titles are used to generate a list of links in site map, screen reader user, person with reading disability or reduced field of vision can't scan the page and reads repetitive information first. SLH: in site map?]] SLH Can you take another pass at the wording on this to make it more clear.]] SLH: This one begs for a visual example...]]

Mobile Context: Page title truncated to fit narrow viewport of mobile device.

top contents list

Focus (tab) order does not match logical document content sequence

SLH: I'm more used to "tab order" and focus order. others?]]

User is unable to navigate content in logical sequence, become disoriented. SLH: become -> becomes]]

Disabilities Context: User with (for example) motor disability uses keyboard for navigation not mouse. SLH: I think you can take out the "for example" here.]] SLH: Add screen reader user?]]

Mobile Context: Pointing device not present or inadequate.

top contents list

Mobile user incurs delay and cost, due to network charges and device limitations. User with disability becomes confused or disorientated; arrives at inaccessible content. SLH: I think both of these can occur with both mobile devices users and people with disabilities. Suggest taking off which user in both sentences - especially since the users are not differentiated in the other Experiences lines.]]

Disabilities Context: User can not determine purpose of link when read out of context SLH: Would it be good to mention that screen reader user often jump to read only the links on a page and thus don't get the context around them? (also, missing period at the end)]]

Mobile Context: User can not determine purpose of link.

top contents list


Information and the operation of user interface must be understandable.

Long words, long and complex sentences, jargon

User has difficulty understanding information.

Disabilities Context: User with cognitive disability has difficulty processing information.

Mobile Context: Text is displayed in small font, and user is often distracted by ambient conditions (background noise, conversations, moving objects in field of vision). SLH: Is it a significant issue for mobile device users when lon sentences are broken across multiple lines? or really long words break in odd places?]]

top contents list

Content spawns new windows without warning user

User becomes disoriented among windows; back button doesn't work. User closes window, not realizing it is last in stack, closing browser instance.

Disabilities Context: User with low vision, restricted field of vision, or blindness doesn't realize active window is new. SLH: add cognitive...]]

Mobile Context: Single window interface. Multiple stacked windows on small screen hide each other.

top contents list

Content blinks, moves, scrolls or auto-updates

User has difficulty reading and comprehending content.

Disabilities Context: People with reading disabilities, cognitive limitations, and learning disabilities do not have sufficient time to read or comprehend information.

Mobile Context: Reduced size of mobile viewport or poor ambient lighting make it difficult to see content. Mobile browsers can behave differently to Desktop browsers, for example due to network and processing capabilities. Auto-refreshed pages may also have cost implications if they are left open or put unnoticed into the background. SLH: Try rewording this to be more clear. Consider limiting it to the most relevant points, and cutting out unnecessary details. (also, lower case "desktop")]]

top contents list


Content must be robust enough that it can be interpreted reliably by a wide variety of user agents, including assistive technologies.

Invalid or unsupported markup

Browser or adaptation system chokes on markup; rejects or garbles it.

Disabilities Context: User's assistive technology or browser can't handle markup.

Mobile Context: Mobile device has embedded browser not supported by content provider. Content passes through adaptation processes. SLH: consider clarifying.]]

top contents list