Only the smallest devices show all the available vocabulary at once. Devices with a larger capacity only show some vocabulary and require the user to "retrieve" words that are not readily visible at first. An individual who is not able to use a retrieval method, or does not use it proficiently, will be unable to use that additional vocabulary during communication. There are three types of message retrieval strategies: a) Levels and Overlays, b) Dynamic Displays and c) Encoding.(Note: Encoding also funcitons as a rate enhancement method.)

Unique messages that an individual produces to say exactly what is intended at a given moment. They are the opposite of "preprogrammed" messages that must be composed and programmed ahead of time. True independence in AAC necessitates the ability to create and deliver novel utterances.

see Picture Exchange Communication System

A type of icon encoding (see above) used in devices by one manufacturer: Prentke Romich Company.

A professional who provides services related to activities of daily living, work, and play to individuals who want to enhance their independence and their quality of life

see Physical therapist

A wand that is held in the mouth and used by individuals with poor hand control to perform some tasks otherwise done by hand, such as reaching & pointing. Some AAC users use mouthsticks to select items on a communication display or device.

The obstacles imposed by other people, preventing AAC users from full participation. For example, a teacher or SLP may believe that non-speakers cannot learn to spell, so literacy instruction is not provided. Or a school may have a policy that prevents a child from taking a communication device home. (Beukelman & Mirenda, 1998)

Gestures, pointing, vocalizations, intonation, body language and facial expression are examples of non-symbolic communication. It is limited to the "here and now," responding to what one sees, hears or feels in the immediate environment.

The output is primarily thought of as the method by which information is conveyed to the partner; e.g. visual output or auditory output. Some devices also connect to computers, cell phones and the internet, a type of "electronic" output that is used to control the environment.