Tangible Symbols as an AAC Option for Individuals with Developmental Disabilities: A Systematic Review of Intervention Studies.

We reviewed nine studies evaluating the use of tangible symbols in AAC interventions for 129 individuals with developmental disabilities. Studies were summarized in terms of participants, tangible symbols used, communication functions/skills targeted for intervention, intervention procedures, evaluation designs, and main findings. Tangible symbols mainly consisted of three-dimensional whole objects or partial objects. Symbols were taught as requests for preferred objects/activities in five studies with additional communication functions (e.g., naming, choice making, protesting) also taught in three studies. One study focused on naming activities. With intervention, 54% (n = 70) of the participants, who ranged from 3 to 20 years of age, learned to use tangible symbols to communicate. However, these findings must be interpreted with caution due to pre-experimental or quasi-experimental designs in five of the nine studies. Overall, tangible symbols appear promising, but additional studies are needed to establish their relative merits as a communication mode for people with developmental disabilities.