As with previous editions, the fourth edition acts as a textbook on AAC, and reflects new knowledge and research findings and also trends in service delivery models. A very positive and refreshing element of this edition is the inclusion of documented experiences of AAC users (including Christy Brown), and of family members.

In addressing the question of what AAC is and how it is used, the focus is not only on AAC, but also the purposes of communication interactions. There is also a focus throughout on the other requirements for success, listed as: linguistic, operational, social and strategic skills or competences. The importance of planning for future AAC needs, not just present needs, is emphasized.

Most examples used are related to assistive technology (AT), but there are many mentions of multi-modal strategies, including manual sign and natural gesture. The concept of Early Communicators is used to cover either very young children or individuals with intellectual disabilities. The book is divided in three parts.