Ganz, J., Hong, E. & Goodwyn, F. (2013). Effectiveness of the PECS Phase III app and choice between the app and traditional PECS among preschoolers with ASD.

Research in Autism Spectrum Disorders, 7, 973‐983.
Abstract: We investigated the efficacy of a tablet‐computer‐based Picture Exchange Communication System (PECS) application for use with three preschoolers with ASD and investigated participant preference for the app versus traditional PECS (i.e., with a physical communication book) once the participants demonstrated minimal levels of mastery of both. Lee Mas...