This module provides an overview of the different types of switches and interfaces that can be used by students with disabilities. The module includes information on characteristics of switches and switch interfaces, mounting systems and suggestions for classroom switch activities.
Purpose of Switch Use
Switches offer access to anything electronic for persons with disabilities. They are a great way to begin experiencing independent control. Through a variety of interfaces, switches are connected to electronic devices. They work to turn things on and off or indicate choices when used with scanning software or interfaces.
For children with physical disabilities, a single, reliable movement can cause a toy to move or turn a radio on. Those with sensory impairments learn that they can be the controlling source of sound, light and vibration. Children with cognitive impairments are able to interact with toys and computers with a single "button," limiting the need for more complex directions. Switches provide new opportunities to learn and participate.
For example, a simple battery interface can
Children often begin by using switches with toys. This develops skills that can include:
These skills provide a foundation for learning and for more complex technology use such as multiple switch use, computer interactions and more extensive environmental control.
Types of Switch Use
Environmental Control of appliances such as radios, fans, blenders, and televisions found in homes and schools.
Play & Exploration are expanded through using switches to independently participate in games and other recreation activities. Battery-operated toys or games such as Light Brite and Spin Art can be easily adapted for switch use.
Communication is encouraged through early switch use. Single switch devices with recorded messages provide a way to relate language to the activity at hand and to initiate and participate in a variety of activities. More complex systems use multiple switches or internal scanning methods to access multi-layered designs.
If a student is having difficulty participating and interacting with objects in the environment, you may decide to try a switch activity with him. Before you begin you need to observe him in his natural environment to determine his best "switch site"-- the body part and movement that he is most consistently able to control. It can be large or small, weak or strong. The movement should be reliable, meaning it can be repeated. A reflexive pattern is not a good choice. Since switches are designed to work with any body part, look for the movement that requires the least expenditure of energy and the one the student prefers. Ask an Occupational Therapist to help.
You may find more than one switch or switch site that can be used during the day as the student's position, energy level and activities change. All of these will affect the selection of the switch and where it is placed. The student should be able to initiate a movement to activate a switch and then be able to sustain and/or release contact with the switch. You can consider additional interfaces to ensure success.
Try a switch activity. Identify an electronic activity that is fun and motivating to the student. [Ablenet (Making Connections, 2001) suggests starting with a musical activity because of its popularity with students.] Select a switch with features that match the abilities of a student. Connect a switch to the music device (i.e. tape recorder). If the student is able to use his fingers, hands or fists, start with these as their interaction with a switch. The resulting response will all be within a contained visual field. Give the student lots of time to practice, encouraging him with cues and praise.
Switches come in all shapes and sizes. The Abledata database (2001) reports the availability of almost 1800 switches! Switches are often activated by the hand or arm, but can be used with any body part. To independently use a switch, a student must be able to voluntarily move any single body part with large or small movements.
There are several categories of switch types. We have grouped them by how a switch is activated. See our handout on switch types for photos and further explanation.
There are several ways to examine a switch to determine its "match" for a student's abilities and preferences. For example, the size of the surface "target" that a student must activate is a primary characteristic. How large does the surface have to be?
Other questions to ask include:
Other features to consider include:
Ask the student which switch he likes. It is important to let him try a variety of switches during different times of the day as his energy and comfort levels may change. For additional information, we offer a handout on switch features.
Switches sometimes must be mounted in place to make them easier to use. This provides stability for the student by ensuring that the switch stays in one place! For push switches we often use pieces of sticky-backed Velcro to hold them in place on a table or desk. For students who access switches in other ways, a mounting system may be useful. Mounts described below hold up to 5 lbs. They are useful for mounting switches or lightweight communication aids.
Universal Mount (AbleNet, Inc.)
MightyMount (Tash, Inc)
Switches can be used with anything electronic, including devices that work with batteries. However, the electronic device will need an interface to use a switch; a place the switch can be plugged in. Switches can control the flow of power to turn things on and off, such as a battery-operated toy or a radio or fan. Items that run on batteries use direct current (DC) while those with plugs use alternate current (AC). Both types can be adapted for switch use with different interfaces. With other interfaces, the same switches can also control complex electronics such as computers and telephones.
Examples of Switch Interfaces
We have also provided a useful handout explaining switch interfaces in detail.
For optimal switch use, several things must be considered:
1. The child should be in a comfortable position. Wherever the child is positioned, in a chair, at a table, or on the floor, the child should be secure so that she can expend energy on participation. She should not be putting effort into balancing or maintaining a particular position. Watch for signs of fatigue.
2. Place the switch near the child's preferred, most reliable access site. Reflexive or abnormal movement patterns should not be considered appropriate sites. Switch placement should not interfere with stable body positioning. Accidental "hits" are natural consequences!
3. Place the device that the child is activating in close proximity to the switch itself. The closer the switch is to the reacting device, the more concrete the cause/effect relationship is.
4. Secure the switch in a stable position so that it doesn't move out of place when activated. Special switch holders are available or items such as suction cups, Dycem (a non-slip material) or a combination of Show Loop fabric (loop Velcro) with hook Velcro adhered to the switch, will stabilize the switch.
5. As children should be repositioned frequently throughout the day, consider more than one switch access site, mounting system, and/or switch for different activities in different positions. The stamina of the child, the environments and activity requirements will help to identify the most successful solutions.
When starting switch use with the student, choose an activity that is motivating to him. Give the student ample time to activate the switch; wait for the response, and describe what happened. Say, "You're making that car move fast," instead of "Good hitting the switch!" This helps the student understand his ability to control action. Switches can be used throughout classroom routines. View our handout on classroom switch activities.
Paint 'N' Swirl (Ablenet)
Battery-Operated Scissors (Ablenet)
Polaroid(r) Impulse Camera [3-PIC]
All-Turn-It Spinner (Ablenet)
Team Extreme (Pathways Group)
Cassette Player + Microphone (Enabling Devices)
Slide Projector Control Adapter (Ablenet)
Adaptivation's Application Photo Album
Recipes for Success (under 2001 Product catalog)
Book of Possibilities (Ablenet)
Burkhart, L. J. (1980). Homemade Battery - Powered Toys and Educational Devices for Severely Handicapped Children. College Park, MD: Author.
Burkhart, L. J. (1985). More Homemade Battery Devices for Severely Handicapped Children. College Park, MD: Author.
Burkhart, L. J. (1987). Using Computers and Speech Synthesis to Facilitate Communicative Interaction with Young and/or Severely Handicapped. College Park, MD: Author.
George, C. & Lacefield, W. (2001). The Handbook of Adaptive Switches and Augmentative Communication Devices (3rd Edition). Lexington, KY: Academic Software.
Goossens, C., & Crain, S. (1992). Using Switch Interfaces with Children Who Are Severely Physically Challenged. Austin, TX: Pro-ed.
Levine, J., & Enselein, K. (1990). Fun for Everyone. Minneapolis, MN: Ablenet.
Levine, J., & Scherfenberg, L. (1986). Breaking Barriers: How Children and Adults can Access the World through Simple Technology. Minneapolis, MN: Ablenet.
Levine, J., & Scherfenberg, L. (1987). Selection and Use of Simple Technology: In Home, School, Work and Community Settings. Minneapolis, MN: Ablenet.
Wright, C. & Nomura, M., (1985). From Toys to Computers: Access for the Physically Disabled Student. San Jose, CA: Authors.