Do augmentative and alternative communication interventions really make a difference?: the challenges of efficacy research

The empirical evidence to support the efficacy of augmentative and alternative communication (AAC) interventions is still quite limited. Further efficacy research is urgently needed to establish best practices, maximize outcomes, ensure accountability, and justify cost. However, conducting efficacy research in the AAC field poses significant challenges because of the heterogeneity of the population of AAC users, the complexity of AAC systems and interventions, and the intricacies of the communication process. This paper discusses some of the challenges confronted when conducting AAC efficacy research—challenges in defining meaningful research questions, determining appropriate methods to investigate these questions, and analyzing the results or outcomes of efficacy research. Some potential solutions to these challenges are discussed and illustrated using examples from current efficacy research on AAC interventions to build communicative competence.