Switch access
From Wikipedia, the free encyclopedia
- See also: Switch Access Scanning
Many people with severe physical or cognitive impairment use one or more switches to access computers. A switch is an assistive technology device that replaces the need to use a computer keyboard or a mouse.
Contents
[edit] Types of switch
Switches come in a variety of shapes and sizes depending on the action used to activate them (such as sip-puff, pushing, pulling or squeezing). Switches also vary in their colour and aesthetics and, for push switches, the amount of force required to operate them. A switch can be operated by any suitable body part that is able to produce consistent and voluntary movement.
[edit] Connecting a switch
A switch cannot be plugged directly into a computer. Instead a Switch Interface is required to bridge the gap between the switch and the computer's USB, serial, or PS/2 port.
[edit] What can be accomplished with a switch
Switches can be suitable for people with cognitive difficulties and developmental delays as they are a clear and simple tool to demonstrate action/reaction. Consequently, the activities the switch is accessing also need to be clear and simple. There are a variety of motivating switch activities that can be used to assess and develop a person's understanding of choice and timing.
Switches can be link to a variety of devices for example: Augmentative and Alternative Communication devices, switch adapted toys, switch interfaces for computer access and environmental control devices
[edit] One switch or two
Some users will prefer to use one switch, others will prefer to use two and sometimes more. For users who are using their switches to access simple activities an additional switch brings about an option of choice. It also allows two users to work collaboratively or to play against each other.
Considering multiple switch access is important for users accessing more advanced activities through scanning. This is usually determined by their physical capabilities. A single switch requires less physical control and is usually less tiring to access but it reduces scanning options and usually leads to a slower rate of input. Single-switch scanning also requires much greater concentration. Two-switch scanning enables a range of scanning options including row and column, and overscan. These can greatly increase input rates and can make using a computer or electronic assitive device far more comfortable and efficient.
