Switch Access.
An overview of switch access.
Learners with significant or multiple impairments may require a customised system for better computer control. Often these methods can integrate with other technologies such as mobility or communication systems to make them more efficient. They also require less effort to control, allowing the student to focus on the activity at hand.
Customised computer options, such as switch access systems look to replace the standard keyboard and mouse. Several combine both standard methods into a totally new one and will often require a combination of a switch and software which is able to simulate keyboard commands and mouse clicks by scanning.
Features in this section:
How do I know which scanning software to choose?
Setting up a switch access system
Types of computer-switch interfaces
On-Line Interactive Scanning Tutorial
Priory Woods School - free switch resources to download
Meldrethmanor School and Learning Alive
Scanning Software
A scan is comprised of equivalent key and mouse choices that appear on the screen when a software program is running. The student goes through (scans) the various commands and then activates a switch to make a choice.
To use a scanning system, a student must be able to:
(The illustration below shows how the scanning action can move through rows using an on-screen keyboard.)
(The user will click or activate the switch at the required point - the scan will then move to the require letter, for example, E, F, G, etc.)
How do I know which scanning software to choose?
The choice of scanning software will be determined by the requirements and ability of each individual student.
There is a range of 'cause and effect' switch programs that introduce the basic concepts of switching, for example the LaraMera range of switch access software.
Touch Balloons can help to develop hand-eye coordination skills by popping balloons as they float past by using a switch.
However, it is well worth considering a program that allows you to set it up to meet individual requirements, for example, Clicker and The Grid.
Setting up a switch access system
In most cases any switch can be used with a variety of computer-switch interfaces to work as single or multiple keys or mouse functions (click, double click, drag).
The concepts are fairly simple. The computer (1) is connected to the computer-switch interface (2) which is then connected to the the switch (3). The interface jack that is used determines what the computer receives when the switch is pressed.
The example on the left shows the Switch Interface Pro (Don Johnston). When the switch is plugged into the first jack, the computer will take the switch activation as a mouse click. When the switch is to act as the Enter key, it must be inserted into the last jack.
Types of computer-switch interfaces
Some switch interfaces combine the switch with the interface into a single device; you simply plug it in and use the switch.
- This works best for a student who can use a "push switch" and who needs only one key/mouse function to control a program.
- Other switch interfaces offer more options, including using a single switch to act as a choice of keyboard/mouse functions.
For more information about scanning methods, e.g., Step Scan, Auto Scan etc, and scanning movements try the CALL Centre's interactive tutorial.
Switch Types and Positioning
When considering which switch to use it is essential that the user is positioned properly in order to exert maximum control over the switch, and that the switch used should capitalise on their most reliable and consistent movement.
Remember to consider the seating and positioning of the individual at an early stage of assessment.
Switches can be placed in a variety of positions, for example, the head, foot, knee etc.
Switches also come in a variety of formats; single, dual and multiple switches.
They can be activated in a variety of ways, for example; pressure switch, movement switch (blinking of the eye), vibration switch, sound switch and a sip and puff switch (by sucking and blowing).
Choosing which input switch should be used by a disabled individual is a very important step in the process.
Selecting the best possible switch for the user can have a dramatic effect on how much progress they can achieve.
On-Line Interactive Scanning Tutorial
This program is a software resource to teach the principles of scanning to anyone who wants to know more about using switches and scanning as a means of accessing a computer.
Although it is still at an early development stage its possible to use different on-screen keyboards (frequency of use) and one or two switches. It is a great resource for those people who are unfamiliar with scanning etc.
Why not test your scanning skills?
Select this link to try the interactive scanning tutorial
(This site is written in Flash so some users might find it difficult to access.)
Priory Woods School
Priory Woods is an all age community special school situated in east Middlesbrough.
As well as providing a quality, inclusive education for pupils with severe learning
difficulties and those with profound and multiple needs, they have a magnificent website.
The Priory Woods resources section contains over 150 programs for switch, touch-screen and pointing device users - all are free to download and include switch activities, cause and effect/targeting activities, interactive storybooks and much, much more!
Select this link to access the resources section
Meldrethmanor School and Learning Alive
There are some great resources a the Melderthmanor School's website, particularly the PowerPoint and Opus switch accessible talking books. To find out more select this link
Learning Alive is a website designed specially for primary and secondary school pupils and their teachers. It is here for you to have fun and assist in filling your brain with useful and interesting information.
There are three sections which make up Learning Alive: Primary, Secondary and Teachers'. These sections will help you find the information which is most relevant to you and by selecting the button in the top right hand corner, you can choose to automatically go back to that section whenever you visit the Learning Alive website