The methodological characteristics of fifty-six studies published between 1980 and 2007 involving the use of augmentative and alternative communication (AAC) by individuals with autism spectrum disorder (ASD) were analyzed. Eighteen investigations implemented sign language or manual signs, twenty-six used picture-based systems, nine employed voice output devices and three worked with hybrid systems, combining two or more AAC modalities. This review focused on identifying the best practices implemented by intervention programs for individuals with ASD, considering measures of internal, external and social validity. A predominance of experimental and quasi-experimental single subject research designs were identified, whereas a limited number of studies employed group designs. Most worked with a reduced number of participants, which were mainly selected in incidental manners. Half of the investigations clearly revealed generalization measures to other behaviors and environments, as well as the sustainability of the results post intervention. A limited number of investigations evaluated participant satisfaction rates with program outcomes. A framework for developing intervention studies with reliable results was further discussed.
Autism; Augmentative and Alternative Communication; Research Methodology; Literature Review
