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Advice and Guidance for Content
Developers
Advice on Adobe® Flash
Flash accessibility issues have heavily focused on screen reader users but it is
important to be aware of the range of issues that affect other disability groups. This
document outlines the most common accessibility issues for disabled people.
Visual impairments
Screen reader users
This is the most obvious group to encounter issues with Flash and typically most
effort is put into fixing these issues. The most common problems are buttons and
controls not being labelled properly or not being labelled at all – for example it is
quite common for screen reader users to hear ‘button button button’ when going
through a list of links on an inaccessible Flash website.
In Flash it is possible to make objects accessible to screen readers via the options in
the accessibility panel (see Fig 1 for an example screen shot). If 'Make object
accessible' is selected a screen reader will read out any text associated with the
object. You can also override this by putting your own text description in the 'Name'
and/or 'Description' fields.
Figure 1: Screenshot of the Accessibility Panel
The Accessibility panel can also be used to provide additional orientation information
for screen readers not shown visually on the screen. For example the four answer
options in Fig 1 have the additional information that they are 'option 1 of 4', 'option 2
of 4' , 'option 3 of 4'and 'option 4 of 4 ' respectively to help a screen reader user
know where they are in the sequence. In addition, to start with all the answer options
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are labelled as 'unselected' - when one is chosen this is dynamically changed by the
ActionScript _accprops property which is discussed in the next section.
Indication of when a question option has been selected
A key requirement in Flash accessibility is to indicate the change of state of objects
on the screen for screen reader users, in this case telling them when they have
chosen (selected) or deselected any of the four answer options via the keyboard.
This is done in ActionScript by the use of the _accprops property - a way of
dynamically changing any of the information in the Accessibility panel.
For example when the third option is selected in the ActionScript the following code
is triggered to change the 'Name' description this: “_accProps.name = "unselected
: option 1 of 4 You should use the ending ‘Yours faithfully’ if your letter starts
Dear Mrs Green.”.";
If the option is then selected again to deselect the choice then accProps.name is
called again to reset to the option 'unselected...'.
To make this work you also need to add the ActionScript statement:
'Accessibility.updateProperties();' once to update the Accessibility panel after the
_accProps statements. In this way a screen reader user receives auditory feedback
on an answer option choice they have made by hearing 'selected...' when they read
the answer description.
Logical reading order through the page
Other problems include orientation and comprehension issues, it is often hard to
make sense of a movie if the reading order does not follow a logical sequence,
especially if no summary information is provided about what content is on the
screen.
In a Flash movie a screen reader follows a reading order on the page which in Flash
can either be left as the standard left to right top to bottom order or you can set a
specific reading order via the TabIndex property.
In ActionScript The TabIndex on the page is set as the lowest number is read out
first the highest last, so for example for the first two movie buttons in Fig 2 they are
set as follows:
this.mc_exit.tabIndex =10;
this.mc_toolshed.tabIndex =20;
And so on...
For a screen reader it is not just the selectable buttons that are part of the reading
order - every accessible object on the screen is part of the reading order and has a
specific TabIndex value, as you can see from Fig 2 below the order is set in a logical
sequence that is understandable to screen readers but is not a logical visual
sequence. The reason for this is that the page heading 'Opening a document - How
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much do you know? is at the bottom of the page and not the top, so to avoid
disorienting a screen reader it is set as fourth in the reading order sequence.
Figure 2: Screen reader reading order
Looping Flash animations
Additionally a common complaint is around the use of looping Flash animations –
which causes a screen reader to go to the top of the page every time the content in
the movie refreshes which is a very frustrating experience.
Interaction issues
Also there are interaction issues – often a screen reader user can navigate around a
Flash application and read the content but when it comes to interacting with
elements such as multiple choice and drag and drop options they become very
frustrated because the controls don’t work properly and tend to be very visually
focussed – this typically stems from developers not testing with a screen reader
through the whole design process.
Moderate vision impairment - Magnification users
People with moderate vision impairments need to use Magnification technology to
blow up the content on the screen to make it readable for them. Often magnifiers
have a reader function built in to read out text as well. The most typically
magnification range is x4 - x6 but it can increase to x32 which is in reality rarely used
– an individual using this magnification would normally have to use a Screen reader
instead. Flash historically has not supported magnifiers, however this has changed
recently with the ZoomText Screen reader now having basic support.
It is worth noting that Flash does have an inbuilt zoom feature, unfortunately this is
not well known and requires the user to use the mouse to move around the enlarged
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Flash movie. Also this feature is frequently disabled for learning packages so is not
commonly used.
The most important issue for magnification users is having a consistent layout on
each screen as only a portion of the screen is seen at any one time, therefore it
helps to know that, for example, the ‘back’, ‘forward’ and ‘help’ buttons are always in
the same place. Information is easier to read in one column rather than across
multiple columns; a problem commonly encountered in online forms is where one or
two of the fields have been put on the right of the main set of fields; these are often
missed when users are filling in forms. Additionally if a ‘search’ or ‘go’ button is not
close to a form, for example because it has been right justified and the form has
been left justified, users have to hunt around to find the button.
Mild vision impairment
The main issue for people with mild vision impairment is the need to enlarge the text
size and change the background and font colours to improve contrast. Which is one
reason why it is important to give users customization options as close to the start of
the course as possible – it is a frequent complaint that users set up their preference
for a webpage and when they move to a Flash based page all their settings
disappear which can be find frustrating.
This group also might potentially use the Zoom Flash feature – Zoom In / Zoom Out
as shown below in Fig 3 – but again many users are not aware of this option and
those who are aware do not always find it helpful, especially as there are no scroll
bars - users have to use the mouse to navigate around the enlarged movie
Figure 3: The zoom function available in Flash
Dyslexia
People with Dyslexia have a range of issues with seeing information on the screen –
it is such a diverse group that it is difficult to cater for every need. Perhaps the most
useful step is to offer a colour contrast scheme that has a beige (or pastel)
background – a white background is often too harsh to look at and the beige or
pastel colour can make the text easier to read. The text should be left aligned as
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fully justified text can be difficult to read due to the uneven spacing between the
words, which causes the gaps to stand out more than the words.
Font styles are also an issue for people with Dyslexia – san-serif fonts such as Arial,
Tahoma and Verdana are easier to read for most people. Typically slightly larger
font size, for example 14pt, than standard (usually 12pt) is helpful, and wider line
spacing can make the text easier to read.
Often people with Dyslexia will use third party software to read out text on the
screen, for example TextHelp’s Read and Write which is not compatible with Flash.
It is therefore important to consider what audio options are available in courses –
ideally you would have the option for all the content on the screen to be read out
with a replay facility to ensure this group would be able to get the best out the Flash
based courses.
Cognitive impairments
Other impairments, for example those that affect memory and attention span, impact
on people’s ability to process the information on the screen. The key requirements
for this group are to have consistent layout that is easy to navigate and not to have
too much distracting movement on the screen – animations that run once and them
stop are fine, however continuous animation can be particularly distracting for this
group.
Mobility impairments
Hand arm dexterity problems
People with hand and arm dexterity problems often use alternative devices to the
standard mouse, or they will rely solely on the keyboard if it is too uncomfortable to
use a pointing device.
For those that use an alternative pointing device it is important that links and buttons
are of a reasonable size to allow for the reduced level of dexterity - if they are too
small or too close together some people with find it difficult to navigate and interact.
Users relying on keyboard navigation need to be able to tab through the Flash based
courses and selected options and interact in such a way that all the controls work –
an obvious area where this would be an issue is the drag and drop type exercise.
Voice Recognition users
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Voice recognition users can face serious issues with
Flash as there is currently no interface between
Flash and the voice recognition software. Users
therefore rely on a basic interaction system called
mousegrid (see Fig 4). The user begins with a 3 x 3
numbered grid that fills the screen. By selecting a
number the user focuses on a particular part of the
screen. This step is repeated until the pointer is over
the target link which is selected using the voice
command ‘Click’.
This can make using Flash a long winded process
but it is possible to navigate a course, exercises
such as drag and drop that require the use of a
mouse may prove to be a problem.
Figure 4: Example of a mouse
grid used in voice recognition
software
Deaf and Hard of hearing
Hard of hearing and Deaf users obviously need captions for any video and audio
content. For British Sign Language (BSL) users there is a language issue because
BSL as a language has a smaller vocabulary than standard English so a significant
number of words will not be covered. For example, research by the BBC looked at
the interaction between BSL users and their website and found that some words, for
example ‘marinade’, were not understood by BSL users. Their solution was to use a
glossary for words whose meaning might be unclear – they had to term this ‘Jargon
Buster’ as the word glossary itself does not exist in BSL!
Learning Disabilities
For those with learning disabilities it is not easy to make training material fully
accessible. The use of plenty of icons and graphics that are clear and intuitive,
simple language and consistent navigation are elements that can be particularly
helpful.
Further advice and guidance on Flash accessibility for developers
Adobe® Best Practice Guide on accessible Flash:
http://www.adobe.com/resources/accessibility/best_practices/best_practices_acc_fla
sh.pdf
http://www.skillsforaccess.org.uk/howto.php?id=141
http://www.skillsforaccess.org.uk/howto.php?id=93
http://www.skillsforaccess.org.uk/howto.php?id=97
http://www.skillsforaccess.org.uk/howto.php?id=147
http://www.skillsforaccess.org.uk/howto.php?id=137
http://www.skillsforaccess.org.uk/howto.php?id=101
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Standards relating to Flash accessibility
W3C WCAG version 2.0
(due to replace WCAG 1.0 in late 2008): http://www.w3.org/TR/WCAG20/
Relevant guidelines:

1.1 Text Alternatives: Provide text alternatives for any non-text content so that
it can be changed into other forms people need, such as large print, braille,
speech, symbols or simpler language

1.2 Time-based Media: Provide alternatives for synchronized time-based
media

1.3 Adaptable: Create content that can be presented in different ways (for
example simpler layout ) without losing information or structure

1.4 Distinguishable: Make it easier for users to see and hear content including
separating foreground from background

2.1 Keyboard Accessible: Make all functionality available from a keyboard

2.2 Enough Time: Provide users enough time to read and use content

2.3 Seizures: Do not design content in a way that is known to cause seizures

2.4 Navigable: Provide ways to help users navigate, find content and
determine where they are

3.1 Readable: Make text content readable and understandable

3.2 Predictable: Make Web pages appear and operate in predictable ways

3.3 Input Assistance: Help users avoid and correct mistakes

4.1 Compatible: Maximize compatibility with current and future user agents,
including assistive technologies
W3C WCAG version 1.0:
http://www.w3.org/TR/WCAG10/ (due to be replaced by WCAG version 2.0 in late
2008):
Relevant checkpoints:

Checkpoint 1.1 Provide a text equivalent for every non-text element.

Checkpoint 1.3 Provide an auditory description of the important information of
the visual track of a multimedia presentation.

Checkpoint 1.4 For any time-based multimedia presentation, synchronize
equivalent alternatives with the presentation.

Checkpoint 1.5 Provide redundant text links for each active region of a clientside image map.

Checkpoint 2.1 Ensure that all information conveyed with color is also
available without color
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
Checkpoint 7.1 Until user agents allow users to control flickering, avoid
causing the screen to flicker.

Checkpoint 7.2 Until user agents allow users to control blinking, avoid causing
content to blink.

Checkpoint 7.3 Until user agents allow users to freeze moving content, avoid
movement in pages.

Checkpoint 7.4 Until user agents provide the ability to stop the refresh, do not
create periodically auto-refreshing pages.
IMS Guidelines for Developing Accessible Learning Applications:
http://www.imsglobal.org/accessibility/accessiblevers/index.html
Relevant sections:


3. Principles for Accessibility in Online Distributed Learning
5. Guidelines for Accessible Delivery of Text, Audio, Images, and Multimedia
Adobe Guidelines for Accessible Flash - Flash 8 Best Practices - Guidelines
for Accessibility in Flash:
http://www.adobe.com/devnet/flash/articles/flash8_bestpractices_09.html
PAS 78: Publicly Available Specification 78: Guide to good practice in
commissioning accessible websites.
Relevant sections:

7.5.3 Flash: Advice on optimising accessibility when providing content in
Adobe Flash.
Section 508 Standards
(US technical standard for accessibility of web content)
http://www.section508.gov/index.cfm?FuseAction=Content&ID=12
Relevant checkpoints of Section 508 Technical Standard 1194.22 Web-based
intranet and internet information and applications:

(a) A text equivalent for every non-text element shall be provided (e.g., via
"alt", "longdesc", or in element content).

(b) Equivalent alternatives for any multimedia presentation shall be
synchronized with the presentation.

(c) Web pages shall be designed so that all information conveyed with color is
also available without color, for example from context or markup.

(j) Pages shall be designed to avoid causing the screen to flicker with a
frequency greater than 2 Hz and lower than 55 Hz.

(k) A text-only page, with equivalent information or functionality, shall be
provided to make a web site comply with the provisions of this part, when
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compliance cannot be accomplished in any other way. The content of the
text-only page shall be updated whenever the primary page changes.

(m) When a web page requires that an applet, plug-in or other application be
present on the client system to interpret page content, the page must provide
a link to a plug-in or applet that complies with §1194.21(a) through (l).

(n) When electronic forms are designed to be completed on-line, the form
shall allow people using assistive technology to access the information, field
elements, and functionality required for completion and submission of the
form, including all directions and cues.

(o) A method shall be provided that permits users to skip repetitive navigation
links.

(p) When a timed response is required, the user shall be alerted and given
sufficient time to indicate more time is required.
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