Important notice about the «ADG» project
Important notice: Due to large demand, the «Accessibility Developer Guide» project (currently a proof of concept with low priority) will become a top priority priority in 2017. We will make this guide become what it deserves to be for so long already: a comprehensive resource for all folks interested in accessibility. For this we need your support!
Typical disabled users: their preferred tools and workflows
Keyboard users with a motor disability
There are two kinds of Users that can’t use a pointing device to control a Computer. The first category of disabled keyboard users suffers from a motor disability which affects the hands so that they are unable to physically hold or to manipulate a pointing device. On the other hand there are blind users there are unable to see the mouse pointer at all. About these users I will talk later.
The typical keyboard user with a motor disability is using either a standard sized keyboard or a special keyboard witch is bigger den a normal keyboard to avoid typing error coursed by unwanted movements of the arms and fingers. The Layout of these big keyboards can be the same as on a standard keyboard but it can be also different depending on the typing skills of the user. The special keyboards connect through a driver as a standard keyboard to the PC or the Mac.
No matter how this users interact with their keyboard they use the tabulator key to jump from focusable element to focusable element on a page such as links, edit fields etc. To scroll on a page they are using the arrow keys and to open a dropdown list the Short key alt+ arrow down. To activate a link the keyboard user presses enter on the focused link. These are all means of navigation that they have.
There are experienced users with no disability at all that before to use the keyboard, too because there are faster that way.
Blind users using a screen reader software
For blind users input is no problem at all. The most of them are able to touch-type. Another story is to control the output of a Computer. For that blind people are depend on special software called screen reader. A screen reader is software that basically read the content of the screen aloud while the user interacts with the computer. A screen reader is more complex then this free text to speech things that one can download from the internet and that reads text aloud after the user has highlighted it with the mouse. There are free screen readers such as NVDA that can be downloaded, too.
A screen reader reads a text line by line, so that blind users don’t have the overview over a webpage or a word document as a sighted user would have. That fact makes it more complicated to not to lose the orientation on a Website. Especially on the dynamic websites that are today quite common is the navigation with a screen reader not always easy. Another fact that developer of websites must consider is a screen reader doesn’t read from the screen in a browser instead of that, it attempt to analyse the HTML code that the browsers provide.
To navigate on a Webpage a blind user is depend on the keyboard. Unlike a user that uses only the keyboard the Screenreader user has more possibilities to navigate on a webpage. The most screen readers offer the possibility to jump direct to different element of a Webpage like headers, lists, edit fields, tables etc. The screen reader presents the Webpage like a text to the blind users, so that one can navigate like in a word document using the arrow keys.
Most screen reader users use the arrow keys to read a text, more experienced users take advance of the possibilities to jump to the different elements on a webpage such as headers, links, lists and paragraphs .That enables the blind User to skip elements of a webpage that occur on each page such as the navigation.
Using a braille display
A braille display is a device that displays a part (between 12 to 80 characters at the time, depends on the length of the device) of a line of text in braille. In order to read a whole line of text the user has to shift the focus of the braille display to the next junk of text. To make it easier to get the cursor on the position where one read on the braille display there is a mechanism called routing keys. This is a row of tiny keys above the braille elements of the braille display, so when the blind users find a typing error in a text he moves the finger slightly and press the routing key above the wrong character and the courser jumps to the corresponding braille element, in a similar way one can activate a link on a website.
The smaller device typically used in conjunction with mobile device such as smartphones or tablets.
Some screen reader users uses in conjunction with the screen reader a braille display. The braille display is basically used to read text in addition to the speech, sometimes the pronunciation of the synthetic speech is hard to understand or the braille display is used to spellcheck a text. The braille display is controlled by the screen reader software. That means for the Developer of a website it make no difference whether a blind user use a braille display or not.
Using a magnifier software
A magnifier software enlarges the content of the screen up to 20 time of the original size and displays it in different false colour e.g. black on yellow, grayscale or in invert colour. Depend on the needs of the visually impaired person it is possible the screen to split e.g. a window on the top of the screen shows the enlarged part of the screen while the other half of the screen shows the content in normal size. However most people prefer a full screen magnifier setting where the whole screen gets enlarged. That means that one can see only a portion of the content of the screen, to see the entire content the user have to shift the focus of the magnifier by using the mouse pointer which get tracked by the software. By the way the courser in a word processor e.g. get tracked as well, so that the user can write without losing the position in a text.
The fact that the user is unable to see the whole content of the screen at once the orientation on the screen becomes a bit of a problem. The user is forced to scan the screen for specific information I myself scan the screen always from the left top edge to the right lower edge. The user must build a mental picture of the screen so that he can quickly find specific content. This made the orientation on a webpage complicate.
Most users who using a magnifier software are using the mouse pointer to operate a webpage others prefer to use the keyboard because there are faster that way.