Due to a variety of causes, an individual may have difficulties to communicate with others. The lack of an effective channel of communication tends to cause limited exchange of ideas, frustration, and underachievement toward personal educational and functional daily living goals. A series of alternative and augmentative communication (AAC) approaches and devices have been developed to help individuals with disabilities for them to become more efficient in enhancement of communication. This handbook is to provide educational, therapeutic, and rehabilitation practitioners, parents and families, and other service providers with basic information relating to AAC. It offers a foundation of practical knowledge-based information, concepts and the how-to' suggestions for accomplishing each individualized AAC-facilitated educational or rehabilitation plan. "