Choosing access method
Individuals with physical disabilities can have great difficulty coordinating their movements to select messages on a communication device. Therefore, the selection method chosen for an individual must be the easiest and fastest. In other words, selection should require as little thought for the AAC user as speech requires for those of us who use speech. Choosing a method of selection can be very easy. A person who has good control of his fingers, hands and arms on at least one side of his body might be able to use those body parts to select. Some individuals use their feet or eyes. However, it can be more challenging if an individual has less control over parts of their body. Many decisions need to be made along the way to ensure the selection method is as easy as possible.
Direct and indirect selection
Direct selection is directly using a part of the body or tool to make a choice. On our telephone, we use our finger to directly select the numbers on the dial pad. In a geography lecture, the professor may use a light pointer to indicate an area on a large map. When using direct selection the individual is able to point to all possible message choices (symbols, words, letters, etc.) on their communication device. They can directly select using their fingers, hands, eyes, toes; or through the use of a pointing device such as a head pointer, mouth stick, beam of light, or pointing using eye gaze. Indirect selection means that the AAC user is not touching the device himself. Instead, there are steps in between which allow them to make the selection (Cook A. M. & S. M. Hussey. 1995. Assistive Technologies: Principles and Practice. St. Louis, MO: Mosby-Year Book, Inc.).
Scanning is the most common type of indirect selection. Scanning involves the systematic presentation of a symbol (icon, letter, word, etc.) choice visually and/or auditorily to the user. The user selects the message by activating a switch (that may be located next to their head or hand for example) at the moment the cursor or indicator electronically highlights the desired word, letter or icon. Switch Direct Joystick Head Stick Selection Copyright © 2014 DynaVox Mayer-Johnson. AAC 101
Choosing a primary and/or secondary selection method
Consider this example: For most of the day, Harold is positioned in a wheelchair. His communication device is mounted to his wheelchair and he can use his hand to select messages. Harold’s primary selection method is direct selection with his finger. However, late afternoon he usually sits in a recliner. In this position he cannot control his hand as well. How will he access his device? He will need a secondary selection method. In this case, he might use a switch to scan through the messages on his page. Some issues to consider when deciding on the primary (or secondary) selection method include the AAC user’s positioning throughout the day, level of endurance, language and communication needs, attention and concentration. It is important to get input from a variety of sources (occupational therapists, physical therapists, speech-language pathologist, families, caregivers, teachers, vision consultants) when choosing a selection method. Each individual will have information from their own expertise and experience to assist in making the best decision. Once the decision is made, the primary means of selection is not set in stone. It should be reviewed regularly by the team and revised as needed. The main selection method should be a “no brainer” rather than something that needs to be improved. The secondary method of selection may be more challenging motorically or cognitively than the primary. The ease and speed of a selection method has a profound effect on an AAC user’s ability to communicate and should be chosen well. using finger using a head pointer using eye gaze Courtesy of the Rehabilitation Institute of Chicago. Revised June 2014, DynaVox. Copyright notification: User may not copy or distribute these materials except for use with the students, patients, clients, or other individuals who receive instruction, therapy, supervision, assessment, care or other services directly from the user. Otherwise, these materials may not be copied without the written consent of DynaVox Mayer-Johnson.