Comparison of fixed and gradual array when teaching sound-letter correspondence to two children with autism who use AAC.

The purpose of this study was to compare two conditions for teaching two children with autism (ages 4;10 and 5;4) who used Augmentative and Alternative Communication (AAC) to point to the printed letter that corresponded to the spoken letter sounds of /t/ and /m/. In one condition (gradual array), the printed letter was first presented in isolation and then distracter letters were gradually introduced. In the other condition (fixed array), the printed letter was immediately presented in combination with seven distracter letters. Using an alternating treatment design, results revealed that the fixed array condition resulted in a faster rate of acquisition of target skills for both participants. Implications and directions for future research are discussed.