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Home > AAC Features > Access Methods > Direct Selection

A. Direct Selection

Direct selection is difficult to define without using those very words. So, the technical definition is somewhat convoluted: the individual "specifically indicates the desired item in the selection set, without any intermediary steps." (Dowden & Cook, 2002).

But, this is just a complex way of saying that the individual points directly at the item without having to wait for options to be presented. Pointing can be done with the finger or hand or toe, or with any number of pointing tools or even by handing a symbol to the partner. In all cases, he makes his selection directly from the existing options which are available in front of him.

Questions to vendors:
Direct Selection

  1. What variations on key shape and size are possible in a given device?
  2. Can the amount of pressure required to activate keys be modified?
  3. What accessories are available to improve direct selection (e.g. keyguard, arm rest, etc.)?

 

There are five types of direction selection methods used for AAC devices and strategies:

  • Pointing with physical contact and force
  • Pointing without physical contact
  • Pointing with contact and no force
  • Pick up and exchange
  • Voice recognition or speech input

1. Pointing with physical contact and force

In this method, a user points and presses to select an item using a finger, the whole hand, a headwand, mouthstick or even a toe.

Image showing selecting symbols using a finger  
Selecting a symbol using a finger.
TuffTalker
Photo courtesy of Words+, Inc.

2. Pointing without physical contact

You can point without actually touching an object to select it. Some examples of this method are

  • eye gazing at an item (requires a partner to read the gaze)
  • using a light pointer
  • using an infrared pointer

    Here is a system based on infrared sensors and a reflective dot on the forehead:


    (click image to enlarge)
    Headmouse, using infrared sensors
    Origin Instruments Corporation

    A variation on this approach is an eye-gaze board, where the user simply looks at the item he or she wants to indicate. Many companies have sought to make technology that's accessible via eye gaze for communication. The reasoning is simple: The military has long had eye-gaze operated systems for their purposes, why not for AAC?

    Here's a system that functions via eye gaze as interpreted by the computer:

A computer than can be accessed via eye-gaze
Eye-Gaze Communication System
LC Technologies, Inc.

Unfortunately, the clinical application of eye-gaze technology for face-to-face communication (as opposed to computer access) isn't so straightforward. This is true for several reasons:

  1. Eye gaze requires that the overall position of the eyes remains stationary or that the system be recalibrated with each move of the head. This is extremely difficult in some motor impairments.
  2. The computer screen has to be placed directly in front of the user, which interferes with face-to-face interaction between the AAC user and the partner. This may be extremely disturbing to some individuals, particularly those with degenerative conditions who are facing the end of life.

3. Pointing with contact and no force

Some people have the ability to touch items but don't have much physical strength or endurance. Others may not have the fine motor control needed to choose a small button or item. For both types of individuals, AAC devices that don't rely on pressure may answer their needs, for example a device with a touch screen:

The DynaVox 3100 with touch screen
The DynaVox 3100
DynaVox Systems, Inc.

In other cases, it is simply not necessary to push to select an item. For example, a communication notebook requires pointing but no pressure.


(click to enlarge)
Daily Communicators
Interactive Therapeutics, Inc.

4. Pick up and exchange

Few textbooks recognize this as a method of direct selection, but Picture Exchange Communication Systems (PECS) should be seen in that light. There are some individuals who benefit more from a method of communication that highlights communication as an "exchange" between two people. The Picture Exchange Communication System (PECS) is the best-known and most well developed system of this type. However, this access method may be considered without use of the entire PECS system.

Photo of the Picture Exchange Communication System. 
 The Picture Exchange Communication System™
Pyramid Educational Corporation

5. Voice Recognition or Speech Input

Beukelman and Mirenda (1998) describe one additional form of direct selection: voice input or speech recognition. Able-bodied individuals are familiar with this technology in hands-free cell phones installed in expensive automobiles; the individual says something equivalent to "phone," "call," or "office," and the phone dials his or her secretary. This isn't yet a method of direct selection for AAC users because technology hasn't overcome the inconsistencies that are characteristic of most speech impairments. However, the time will come when even the most dysarthric individual will be able to speak commands and then have the device produce intelligible speech output.

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