Two Switches for Success: Access for Children with

Severe Physical and/or Multiple Challenges

(Revised October, 2004)

Linda J. Burkhart, Dale Gardner-Fox M.S., RPT, Gretchen Hanser MS, OTR/L,
Deanna K. Wagner, MS/CCC-SLP

Which Students and Why?

Types of Scanning & the Demands

Active Participation

A Closer Look at the Cognitive & Motor Demands of Scanning
- Sensorimotor demands
- Language components
- Considerations for Parallel Programming

Keeping the Balance
- Motivation
- Motor load
- Cognitive load

A Closer Look at Motor Learning

  • Development and use of cognitive/motor schemas
  • Motor loop
  • Feedback

Stepping Stones to Switch Access

Step 1: Single Switch - Cause and Effect

  • Momentary/direct activation to get started
  • Short timed segments for more active engagement
  • Toys with a mission
  • Simple Means-Ends

Step 2: Single Switch - Multiple Locations and Multiple Functions
  • Locating a switch in multiple locations
  • Developing some motor automaticity, through repetition with moderate differences - without the stress of timing
  • Using a switch with clear intent
  • General social and pragmatic timing
  • Sequenced social scripts

Note: Strive to achieve a balance between leaving a switch in one place long enough for the child to accommodate to it, and experimenting with moving the switch to a place that might be easier for the child to access.

Step 3: Two Switches - Two Functions
  • Increase motivation by increasing cognitive engagement and control
  • Two switches trial and error
  • Two switches positionally related to function (Left Right Switch Activities on this CD)
  • Two switches social turn talking
  • Two switches / two functions - Appropriate pragmatic use of function

Types of Scanning - to increase choices and control

  • Automatic Scanning
  • Inverse Scanning
  • Step Scanning with a Delay
  • 2 Switch Step Scanning
  • Morse Code

Why Two Switch Step Scanning?
    • Eliminate need for Timing
    • Concentration / Distraction
    • Allows for more appropriate social skills and pragmatics
    • Active vs. Passive Control
    • Separate Function for Each Switch: Simple Cognitive Map
    • One switch advances scan with each activation, the second switch selects the item.
    • Very few options are available for a single switch user beyond cause and effect

Different Cognitive Levels:

  • Some children have difficulty moving to two switch step scanning because they do not yet understand the cognitive task. These students will go on to Step 4.
  • Some Children will understand the concept of 2 Switch Step Scanning, as soon as they are shown how it works. These students will go on to Step 5.

Step 4: Learning to Two Switch Step Scan

  • One switch is the “mover” or “lister” and one switch is the “get it” or “selector” switch
  • Children who don’t understand the concept of two switch step scanning, may need this intermediate step to experience one switch as the mover and one switch as the selector.
  • These children may appear to activate the two switches randomly and without discrimination of function.
  • Use battery powered toys to move to a location for a play purpose. Use a delay timer that moves the toy a short distance for each activation. (rotating plate)

Step 4a: Side Step: Single Switch timing - Following this step may lead to variations of steps 5-8 for automatic scanning, inverse scanning or step scan with a delay

  • Some children show an ease of activating the switch that indicates they will be able to activate a switch in a timed mode. For these children, you may want to probe this ability by presenting simple single switch activities that require timing. Experiment with automatic scanning, inverse scanning and single switch step scanning with a delay
  • Other children may not be ready for a timed form of scanning until step 8, at which time, they may have developed enough motor automaticity with a switch to be successful with timed scanning.
  • Some children may always be faster with two switch scanning and never use a timed scanning.

Step 5: Two Switch Step Scan Errorless Learning - any choice works

  • This type of activity offers the child a variety of choices through two switch step scanning, but any response is accepted as the child plays or creates a story, rhyme or errorless letter.
  • Similarly the child can use a series of communication displays to direct the action of another person in a play activity script.
  • The child can “scribble” with a talking word processor with a limited set of letters.
  • The child can use different computer voices to listen to a selected tongue twister or silly saying.
  • The chid can use a communication device to direct action in a game such as follow the leader or draw a face, with options that all make sense.

Step 6: Two Switch Step Scan for Clear Choices: Activities for Increasing Accuracy and Cognitive Engagement:

  • Insert some blanks in the array of choices with a communication display or software activity.
  • Use a word like “click” or “nothing” repeatedly and have the child listen/look for a target word such as: “read”, “sing”, or “show me!” Vary the number of clicks each time.
  • When the child selects one of these choices, the feedback shows that it is somehow not logical or not reinforcing. Hopefully the child will not select that item again, and pay more attention to selecting a fun or appropriate choice.
  • Use partner assisted scanning and model self-talk, “hmm, no, no, yes, that’s what I want”
  • The number of blanks or clicks before a target item, should be varied to prevent the child from just learning a motor pattern, instead of staying cognitively engaged to make a clear choice.
  • Gayle Porter’s light tech multi-page dynamic displays

  • Step 7: Practice for Increasing Accuracy with Two Switch Step Scanning
  • There are an endless variety of activities that can be set up to give children experience with two switch step scanning using authoring programs and communication devices.
  • Try activities with some correct answers and some incorrect answers
  • Add slightly negative or illogical items in the array of choices, or simply “no” and repeat what to listen/look for.
  • For communication displays, select vocabulary items that have different pragmatic intents, so that the responses from the listeners provide clear feedback for the child’s comments.
  • Once the child understands the process, then two switch scanning can provide an access strategy to many curricular applications as well as a means of communication. Music, animation, and logical or humorous sequences are often a good starting place.
  • Use errorless activities that allow the child to be creative and generative: For example, errorless letters.
  • Provide emerging literacy activities for creating stories, playing with sounds and letters, or constructing a rhyme or sentence.
  • Keep motivation high and customized for the child
  • With successful and motivating practice, the child will be developing more motor automaticity, and integration of cognitive and motor tasks

  • Step 8: Two Switch Step Scan Reducing Time for Success

(for children who understand the process of two switch step scanning, and have developed some motor automaticity for the task)

  • Present a limited array at appropriate times to increase efficiency (combining letters with word endings)
  • If the child is just spelling out a controlled set of words, it may be faster for the child to be presented with only the possible letters instead of the whole alphabet array.
  • If the child is creating sentences, selected words can be offered, instead of the child having to spell out each word.
  • Make use of sentence starters, endings and phrases.
  • Use the feature of natural branching to present a limited number of choices at each logical step of a discussion, sequence of activity, composition or story. (For example: the next logical vocabulary needed in a sequenced type activity, automatically appears, instead of having to be navigated to from the main page.)
  • Set up the array so that incorrect pictures or items disappear after one selection.
  • Provide practice for rehearsing or studying for a test in a child-controlled flash card format.
  • Provide multiple choice instead of fill in the blank activities.
  • Provide feedback in the form of a voice-output/written explanation for illogical choices.
  • Utilize electronic "Word Walls" and "Word Banks" to provide access to frequently used words.
  • Consider using word prediction or picture/word prediction.
  • Consider using encoded alphabet displays for spelling.
  • Explore other switch access strategies, such as Morse Code.

  • Linda J. Burkhart
    Gretchen Hanser MS, OTR/L
    Dale Gardner-Fox M.S., RPT
    Deanna K. Wagner, MS/CCC-SLP

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